Journal of Biomedical Optics最新文献

{"title":"Python-controlled multimodal UV-VIS hyperspectral imaging system.","authors":"Elizabeth A Bullard, Erin M Stout, Oscar R Benavides, Anaya Bawiskar, Lakhvir Singh, Ngoc Nhu Vu, Samuel Mabbott, Alex J Walsh","doi":"10.1117/1.JBO.31.9.096003","DOIUrl":"10.1117/1.JBO.31.9.096003","url":null,"abstract":"<p><strong>Significance: </strong>Traumatic and chronic wound healing is a complex process that often requires careful observation by healthcare professionals. Noninvasive optical technologies such as hyperspectral reflectance imaging and tissue autofluorescence imaging detect changes in optical properties related to physiological parameters such as tissue perfusion. Macroscopic hyperspectral systems with a large field of view to visualize tissue structure and perfusion are well suited for wound care.</p><p><strong>Aim: </strong>Here, a custom-built benchtop hyperspectral and autofluorescence imaging system (HySAF) is optimized to measure tissue optical properties. It operates using a custom Python script to allow precise control over acquisition parameters.</p><p><strong>Approach: </strong>HySAF was built using off-the-shelf components, and Python code was written to control primary devices. HySAF's performance was evaluated by imaging oxygenated and deoxygenated blood samples, scattering induced by nanoparticles, scorpion autofluorescence, and rat wounds.</p><p><strong>Results: </strong>HySAF has a large field of view (FOV) with <math><mrow><mn>176.7</mn> <mtext>  </mtext> <mi>μ</mi> <mi>m</mi></mrow> </math> pixel resolution and 10 nm spectral resolution from 420 to 730 nm. Changes in absorbance were observed during blood deoxygenation, nanoparticle presence in cells, and healing wound tissue in rats, while autofluorescence distinguished anatomical parts of the scorpion.</p><p><strong>Conclusion: </strong>HySAF is capable of detecting changes in sample fluorescence and absorbance across visible light with large FOV and could be implemented in clinical applications such as monitoring and assessing wound healing.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 9","pages":"096003"},"PeriodicalIF":3.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13577617/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148976876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Label-free two-photon fluorescence lifetime imaging of FADH₂ for rapid diagnosis and grading of glioma.","authors":"Shiqi Wang, Yixuan Yang, Chaodong Yin, Jiaqing Guo, Yan Xu, Binglin Shen, Shijun Huang, Li Wang, Jie Chen, Shuai Ye, Zhang Hong, Jianqiang Li, Liwei Liu, Lingchao Chen","doi":"10.1117/1.JBO.31.9.095004","DOIUrl":"10.1117/1.JBO.31.9.095004","url":null,"abstract":"<p><strong>Significance: </strong>Glioma diagnosis currently relies on histopathology, which provides essential morphological information but fails to capture the dynamic metabolic heterogeneity underlying tumor progression.</p><p><strong>Aim: </strong>This study seeks to establish a label-free fluorescence lifetime imaging strategy to characterize the metabolic microenvironment of gliomas, with the goal of achieving accurate tumor grading and real-time malignancy assessment.</p><p><strong>Approach: </strong>We developed a phasor plot-based two-photon fluorescence lifetime imaging microscopy (TP-FLIM) system. This imaging approach was utilized to evaluate tumor tissues by mapping microenvironmental phenotypes across four distinct glioma subtypes. In addition, we performed longitudinal <i>in vivo</i> tracking within an orthotopic glioma mouse model to monitor metabolic changes over time.</p><p><strong>Results: </strong>This method successfully identified distinct tissue regions defined as reduced flavin adenine dinucleotide (FADH₂) hotspots. These areas serve as specific metabolic niches that are strongly associated with collagen IV deposition. Furthermore, the longitudinal <i>in vivo</i> tracking validated the feasibility of utilizing these FADH₂ signatures to accurately discriminate varying degrees of tumor malignancy.</p><p><strong>Conclusions: </strong>These findings establish FADH₂ hotspots as a promising and reliable optical biomarker. The study highlights TP-FLIM as a rapid and label-free platform capable of providing intraoperative metabolic navigation, precise diagnosis, and molecular stratification for glioma.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 9","pages":"095004"},"PeriodicalIF":3.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13617214/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149074929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Histopathological analysis for human articular cartilage using a Raman probe system.","authors":"Hiroshi Kiyomatsu, Kosuke Toda, Takashi Katagiri, Akinori Taketani, Kaori Sugiyama, Tatsuhiko Kutsuna, Tomofumi Kinoshita, Takashi Tsuda, Masaki Takao, Yusuke Oshima","doi":"10.1117/1.JBO.31.9.097005","DOIUrl":"10.1117/1.JBO.31.9.097005","url":null,"abstract":"<p><strong>Significance: </strong>The molecular pathogenesis of degenerative alterations in articular cartilage is still not fully understood. Raman spectroscopy using a fiber-optic probe system is a promising approach for the early diagnosis and prevention of joint disorders such as osteoarthritis.</p><p><strong>Aim: </strong>This study aims to characterize the degenerative changes in the joint articular cartilage using a hollow-core fiber Raman probe designed for future arthroscopic use.</p><p><strong>Approach: </strong>Human articular cartilage specimens were obtained from 12 patients who underwent knee ( <math><mrow><mi>n</mi> <mo>=</mo> <mn>5</mn></mrow> </math> ) or shoulder ( <math><mrow><mi>n</mi> <mo>=</mo> <mn>7</mn></mrow> </math> ) arthroplasty. All surgical specimens were measured ex vivo after fixation in 10% neutral buffered formalin. The articular cartilage tissues at the knee, hip, and shoulder joints were obtained from a single cadaver donor. Raman spectra of the cartilage specimens were acquired and analyzed using a handheld Raman probe system.</p><p><strong>Results: </strong>The hollow-core fiber Raman probe detected molecular differences between less-degenerated and degenerated areas in human shoulder and knee articular cartilage <i>ex vivo</i>, with clearer separation in the knee, and additionally revealed joint-specific baseline spectral features among cadaveric shoulder, hip, and knee cartilage.</p><p><strong>Conclusions: </strong>These results support the novelty and translational potential of this probe as a future <i>in vivo</i> arthroscopic tool for objective molecular assessment of cartilage degeneration.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 9","pages":"097005"},"PeriodicalIF":3.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13620353/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149080962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Generalized self-calibrating probe approach for CW tissue oximetry.","authors":"Leila Motamed Jahromi, Lin Yang, Alexander von Lühmann, Dirk Grosenick","doi":"10.1117/1.JBO.31.9.095001","DOIUrl":"10.1117/1.JBO.31.9.095001","url":null,"abstract":"<p><strong>Significance: </strong>Functional near-infrared spectroscopy (fNIRS) and oximetry are important noninvasive methods to investigate physiological processes and states in the human brain and muscle tissue. Self-calibrating probe methods combine two light sources with typically two detectors to improve the stability of continuous-wave (CW) devices, but so far are limited to fully symmetric geometries.</p><p><strong>Aim: </strong>We developed a generalized self-calibrating probe approach to improve accuracy and stability in CW oximetry for arbitrary configurations of two light sources and detectors.</p><p><strong>Approach: </strong>We used the diffusion theory of light transport to derive the effective attenuation coefficient from self-calibrating probes with arbitrary asymmetric source-detector configurations in reflection. The theory was validated by measurements on tissue-like reference phantoms and by a vascular occlusion test on the forearm muscle of a healthy subject using a dual-wavelength CW fNIRS imager. Results were compared with conventional analysis by spatially resolved spectroscopy (SRS). Time-domain measurements served as a reference.</p><p><strong>Results: </strong>The phantom studies with the generalized self-calibrating probe approach provided accurate results for effective attenuation and oxygen saturation for the wide variety of source-detector configurations examined. Results from the SRS method showed a slightly larger spread. When submillimeter shifts of the source positions were neglected in the data analysis, large errors were observed in oxygen saturation for both methods. The vascular occlusion test showed good agreement between the self-calibrating approach and the time-domain reference data. Oxygenation profiles from SRS differed strongly across the source-detector combinations, with significant deviations already for the baseline saturation. When CW measurements were analyzed using literature values for the tissue scattering properties, systematic shifts of the oxygen saturation occured. The shifts remain small when the ratio of the reduced scattering coefficients at the two wavelengths of the CW device is close to the true tissue value.</p><p><strong>Conclusions: </strong>The proposed generalized self-calibrating approach enables quantification of oxygen saturation <i>in vivo</i> for a wide variety of source-detector configurations whereby a good estimate of the ratio of the tissue scattering properties at the two wavelengths is required. Our single-case study shows the potential of the self-calibrating approach to considerably improve the accuracy and stability of CW oximetry for the large dynamic range of a vascular occlusion compared with conventional measurements using SRS with a single light source.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 9","pages":"095001"},"PeriodicalIF":3.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13549469/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148906097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Endoscopic multispectral imaging sensor systems for intraoperative tissue differentiation.","authors":"Andrea Rüdinger, Kira Holstein, Alissa Tarnoruzki, Nora Lösch, Tobias Haist, Stephan Reichelt","doi":"10.1117/1.JBO.31.9.097003","DOIUrl":"10.1117/1.JBO.31.9.097003","url":null,"abstract":"<p><strong>Significance: </strong>To remove the entire tumor area in cancer surgery, the margins are currently assessed by frozen sectioning or by analyzing the resected tissue afterwards. By utilizing spectral differences between healthy and malignant tissue, multispectral imaging (MSI) enables real-time tissue differentiation. Through miniaturization, the system can be used intraoperatively, thereby enabling the surgeon to define tumor margins, which reduces the need for a follow-up surgery.</p><p><strong>Aim: </strong>By obtaining characteristic spectral differences of healthy and malignant breast tissue, a miniaturized multispectral sensor system should be developed. The system should be compatible to commercial endoscopes, so that it can be used in minimally invasive endoscopic procedures.</p><p><strong>Approach: </strong>We analyzed hyperspectral measurements of an <i>ex vivo</i> breast cancer study in the visible to shortwave infrared spectral range (450 to 1390 nm) and defined characteristic spectral differences. With these, we designed two MSI sensor systems, which only use few spectral channels, gaining a potentially real-time-capable sensor system. By miniaturization, they can be used intraoperatively with a commercial endoscope.</p><p><strong>Results: </strong>The final setups can be used with a commercial endoscope and allow for 90 deg field of view and a high spatial resolution, but showed limitations in the SWIR transmission.</p><p><strong>Conclusion: </strong>The two demonstrated systems are promising steps towards real-time endoscopic tissue differentiation.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 9","pages":"097003"},"PeriodicalIF":3.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13597026/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149025067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Weighting scheme for robust depth normalization in reflectance time-domain diffuse optical tomography.","authors":"Ifechi A E Ejidike, Michael G Tanner","doi":"10.1117/1.JBO.31.9.097002","DOIUrl":"10.1117/1.JBO.31.9.097002","url":null,"abstract":"<p><strong>Significance: </strong>Reflectance mode diffuse optical tomography (DOT) is limited in its depth sensitivity. Current approaches to improve depth sensitivity need some prior knowledge to correctly localize deep inclusions. It has been shown that time-domain (TD) measurements can enhance depth sensitivity, but reconstructions still tend to be biased toward the surface, and TD modeling of diffuse light is computationally burdensome. Efficient TD modeling of diffuse light and prior-free reflectance DOT is critical to streamline the adoption of the technology into clinics.</p><p><strong>Aim: </strong>Our aim is to develop an efficient simulation tool for TD fluence in tissue as well a weighted reconstruction algorithm that uses TD measurements to enhance both the depth sensitivity and spatial selectivity of DOT without relying on any prior knowledge of the tissue structure or inclusion location.</p><p><strong>Approach: </strong>To overcome the computational burden of TD modeling of diffuse light, we solve the diffusion approximation in the Fourier domain for many frequencies parallelizing our solver across mesh nodes, sources, and frequencies. Using only the sensitivity matrix calculated from this modeled fluence, we calculate a weighting matrix that optimizes the spatial selectivity and depth sensitivity of our measurements. This weighting matrix was used in a Levenburg-Marquardt algorithm to retrieve the three-dimensional absorption profile of single inclusions at different depths, two complex scenes with inclusion(s) that spanned the depth of the sample, and computational phantoms adapted from publicly available breast lesion magnetic resonance imaging data.</p><p><strong>Results: </strong>We found in our simulations that our weighted scheme enables enhanced spatial selectivity for diffuse measurements as well as flattening the net sensitivity across the depth of the sample for DOT. We were able to accurately localize inclusions up to 40 mm deep without using prior knowledge of inclusion depth to normalize the sensitivity. Investigations of the effect of shot noise and Monte-Carlo-generated data on our reconstructions revealed we are still able to localize inclusions up to 30 mm deep for realistic noise levels. The complex targets were also well reconstructed up to 40 mm for noise-free measurements and up to 30 mm for the same noise levels. We found our regularization parameters had limited dependence on the geometry or ground truth optical property distribution. For all our reconstructions, we only tuned the regularizer used to find the weighting matrix based on the noise level.</p><p><strong>Conclusions: </strong>We demonstrate by simulation a weighting scheme for diffuse measurements and DOT that greatly enhances spatial selectivity and depth sensitivity, with no explicit depth prior. As well as this, we demonstrate the robustness of our approach by reconstructing complex targets with the same initial parameters used throughout.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 9","pages":"097002"},"PeriodicalIF":3.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13576694/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148976913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and optical characterization of a multilayered head phantom for optical brain monitoring.","authors":"Karina Awad-Pérez, Maria Roldan, Panicos A Kyriacou","doi":"10.1117/1.JBO.31.9.095003","DOIUrl":"10.1117/1.JBO.31.9.095003","url":null,"abstract":"<p><strong>Significance: </strong>Optical techniques are promising tools for non-invasive cerebral monitoring; however, optical measurements acquired from the forehead can be influenced by extracranial tissues and skin pigmentation, potentially complicating interpretation of cerebral signals. Tissue-mimicking phantoms provide controlled platforms for studying these effects; however, existing head phantoms employ simplified geometries and lack the features required for cerebral photoplethysmography (PPG) investigations.</p><p><strong>Aim: </strong>We present the development and characterization of a multilayer head phantom reproducing key anatomical, optical, and hemodynamic features relevant to optical brain monitoring while enabling future investigation of confounding factors.</p><p><strong>Approach: </strong>The phantom incorporates a custom-made silicone brain with embedded vessels, a three-dimensional-printed skull, a vascularized scalp, and interchangeable skin layers representing different pigmentation levels, integrated with an <i>in vitro</i> cardiovascular system enabling selective perfusion of cerebral and extracranial compartments. The optical and colorimetric properties of the tissue-mimicking layers were assessed.</p><p><strong>Results: </strong>The scalp and skin layers exhibited absorption and reduced scattering coefficients within ranges reported for human tissues. Colorimetric assessment confirmed physiologically relevant pigmentation characteristics across the skin layers. Using the pale skin, the phantom generated measurable PPG signals across multiple wavelengths and source-detector separations.</p><p><strong>Conclusions: </strong>The multilayer head phantom provides an anatomically and optically representative platform for optical brain monitoring research. Its interchangeable skin layers and independently perfusable cerebral and extracranial compartments enable future controlled investigations of skin pigmentation and extracranial hemodynamics as confounding factors in cerebral optical measurements.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 9","pages":"095003"},"PeriodicalIF":3.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13587242/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149008579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of surgical resection on tissue autofluorescence lifetime signatures in head and neck cancer: implications for intraoperative tumor margin assessment.","authors":"Farzad Fereidouni, Willy Ju, Sarah Rezapourdamanab, Dena Sayrafi, Mohamed Abul Hassan, Brent Weyers, Xiangnan Zhou, Julien Bec, Dorina Gui, Andrew Birkeland, Laura Marcu","doi":"10.1117/1.JBO.31.9.096002","DOIUrl":"10.1117/1.JBO.31.9.096002","url":null,"abstract":"<p><strong>Significance: </strong>Accurate identification of residual tumor during head and neck cancer surgery is essential for preventing local recurrences and improving patient outcomes, yet current methods for intraoperative margin assessment remain limited. Fluorescence lifetime imaging (FLIm), a label-free optical technique, has shown strong potential for distinguishing cancerous from noncancerous tissue <i>in vivo</i>. However, the effect of tissue resection on autofluorescence properties is not well defined, raising the question of whether diagnostic signatures established<i>in vivo</i> translate reliably to <i>ex vivo</i> specimens.</p><p><strong>Aim: </strong>The aim is to characterize how fluorescence lifetime properties change between <i>in vivo</i> and <i>ex vivo</i> conditions across multiple head and neck anatomical sites and to assess how these changes affect diagnostic separability between cancerous and noncancerous tissue.</p><p><strong>Approach: </strong>A custom fiber-based, point-scanning FLIm system with phasor-based analysis was used to characterize fluorescence lifetime features <i>in vivo</i> and <i>ex vivo</i> across oral tongue, base of the tongue, and palatine tonsil tissue from 75 patients undergoing oropharyngeal surgery. A separability index based on phasor distributions was used to quantify cancer versus noncancer contrast across multiple spectral channels.</p><p><strong>Results: </strong>Resection-induced changes in decay dynamics and fluorescence lifetime values varied by anatomy: oral tongue and tonsil showed reduced contrast <i>ex vivo</i>, whereas the base of tongue demonstrated improved separation after excision. The base of the tongue showed a higher separability index <i>ex vivo</i> (0.43 versus 0.15 <i>in vivo</i>), whereas oral tongue and tonsil maintained superior contrast <i>in vivo</i> (0.27 versus 0.18 and 0.46 versus 0.28, respectively).</p><p><strong>Conclusions: </strong>Surgical resection substantially alters autofluorescence signatures in an anatomy-dependent manner, emphasizing the need to train and validate diagnostic algorithms independently for <i>in vivo</i> surgical guidance and <i>ex vivo</i> pathology assessment.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 9","pages":"096002"},"PeriodicalIF":3.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13544624/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148897375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Label-free wide-field imaging of brain tumors using near-infrared endogenous fluorescence and reflectance normalization.","authors":"Gabriel Beaudoin, Victor Blanquez-Yeste, Frédérick Dallaire, Seung Soo Lee, Romain Cayrol, Marie-Christine Guiot, Mark A Trifiro, Miltiadis Paliouras, Kevin Petrecca, Frédéric Leblond","doi":"10.1117/1.JBO.31.8.086005","DOIUrl":"10.1117/1.JBO.31.8.086005","url":null,"abstract":"<p><strong>Significance: </strong>Maximizing safe tumor resection remains a major challenge in brain tumor surgery due to the lack of reliable real-time intraoperative contrast between tumor and healthy brain tissue. Label-free optical methods based on endogenous tissue fluorescence could provide simple, noninvasive feedback to guide resection while avoiding the logistical and regulatory limitations of exogenous fluorophores.</p><p><strong>Aim: </strong>The study aims to investigate whether endogenous near-infrared (NIR) fluorescence can differentiate tumor from normal brain tissue <i>in vivo</i> and to develop a wide-field fluorescence and reflectance imaging system for label-free visualization of brain tumor specimens <i>ex vivo</i>.</p><p><strong>Approach: </strong>We analyzed <i>in vivo</i> data acquired with a hand-held near-infrared spectroscopy probe from 26 patients (430 measurements) to quantify endogenous fluorescence differences between glioblastoma or astrocytoma and normal brain. Based on these findings, we built a wide-field imaging prototype using 808-nm laser excitation, red-shifted fluorescence detection with an InGaAs short-wave infrared camera, and co-registered reflectance imaging for ratiometric normalization. The system was validated with <i>ex vivo</i> human surgical specimens (14 samples from five patients).</p><p><strong>Results: </strong>Endogenous fluorescence intensity measured <i>in vivo</i> was significantly higher in normal brain tissue compared with tumor, yielding positive predictive values of 85 to 88% for tumor and a negative predictive value of 96% for normal tissue. <i>Ex vivo</i> wide-field imaging reproduced this contrast: normalized fluorescence was lower in tumor regions than in histologically confirmed normal areas, consistent with metabolic differences observed <i>in vivo</i>.</p><p><strong>Conclusions: </strong>Endogenous NIR fluorescence provides intrinsic contrast between normal and tumoral brain tissue. The demonstrated corrected wide-field fluorescence imaging approach could offer a feasible, label-free method for real-time visualization of tumor margins, supporting its future clinical translation as an intraoperative guidance tool.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 8","pages":"086005"},"PeriodicalIF":3.3,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13463984/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148724951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Freeform extended depth-of-focus intraocular lens for more robust performance against physiological variations.","authors":"Julien Charlot, Thierry Lépine, Fannie Castignoles, Vincent Nourrit","doi":"10.1117/1.JBO.31.8.085002","DOIUrl":"10.1117/1.JBO.31.8.085002","url":null,"abstract":"<p><strong>Significance: </strong>Extended depth-of-focus (EDOF) intraocular lenses (IOLs) aim to provide improved visual performance over a range of distances, but their clinical outcomes are still sensitive to individual biometric variability. Improving the robustness of EDOF IOL optical performance to these patient-specific variations is critical to enhance visual predictability and patient satisfaction following cataract surgery.</p><p><strong>Aim: </strong>We aim to determine if freeform surfaces can improve the robustness of EDOF IOLs by maintaining consistent optical performance (refractive error, depth of field) despite individual biometric variations.</p><p><strong>Approach: </strong>A database of synthetic eyes was adapted to simulate pseudophakic eyes. The post-operative performances (refractive error and depth of field) for three types of EDOF IOLs (L1, L2, L3) were estimated using polychromatic Visual Strehl ratio based on the Optical Transfer Function, with photopic wavelength spectrum for a 3 mm and a 5 mm entrance pupil diameter. L1 is a standard refractive EDOF; L2 is identical to L1 but with a freeform back surface optimized in-eye; L3 is similar to L2 but calculated by a model trained to predict freeform surfaces, using preoperative biometric data (higher-order aberrations of the cornea; effective lens position, calculated from preoperative data; ELP-retina distance; and transverse position of the lens).</p><p><strong>Results: </strong>The addition of a freeform surface allowed us to significantly reduce the difference between the target refraction and subjective refraction, in polychromatic condition, for small and large pupil sizes while maintaining the depth of field. Performances with L3 were equal to L2.</p><p><strong>Conclusions: </strong>The use of a freeform surface can significantly reduce the impact of individual biometric variations such as corneal aberrations and transverse IOL positioning on EDOF behavior lenses, for small and large pupil sizes.</p>","PeriodicalId":15264,"journal":{"name":"Journal of Biomedical Optics","volume":"31 8","pages":"085002"},"PeriodicalIF":3.3,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13504705/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148818585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}