Volume 28 Issue 8 | Journal of Biomedical Optics

Journal of Biomedical Optics

VOL. 28 · NO. 8 | August 2023

CONTENTS

IN THIS ISSUE

Review Papers (3)

Special Section on Seeing Inside Tissue with Optical Molecular Probes (9)

General (3)

Imaging (4)

Microscopy (1)

Sensing (2)

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Review Papers

Review of optical reporters of radiation effects in vivo: tools to quantify improvements in radiation delivery technique

Jacob Sunnerberg, William S. Thomas, Arthur Petusseau, Matthew S. Reed, P. Jack Hoopes, Brian W. Pogue

Journal of Biomedical Optics, Vol. 28, Issue 08, 080901, (August 2023) https://doi.org/10.1117/1.JBO.28.8.080901

TOPICS: Radiotherapy, In vivo imaging, Oxygen, Radiation effects, Tissues, Molecules, Tumors, Radio optics, In vitro testing, Skin

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Significance

Radiation damage studies are used to optimize radiotherapy treatment techniques. Although biological indicators of damage are the best assays of effect, they are highly variable due to biological heterogeneity. The free radical radiochemistry can be assayed with optical reporters, allowing for high precision titration of techniques.

Aim

We examine the optical reporters of radiochemistry to highlight those with the best potential for translational use in vivo, as surrogates for biological damage assays, to inform on mechanisms.

Approach

A survey of the radical chemistry effects from reactive oxygen species (ROS) and oxygen itself was completed to link to DNA or biological damage. Optical reporters of ROS include fluorescent, phosphorescent, and bioluminescent molecules that have a variety of activation pathways, and each was reviewed for its in vivo translation potential.

Results

There are molecular reporters of ROS having potential to report within living systems, including derivatives of luminol, 2′7′-dichlorofluorescein diacetate, Amplex Red, and fluorescein. None have unique specificity to singular ROS species. Macromolecular engineered reporters unique to specific ROS are emerging. The ability to directly measure oxygen via reporters, such as Oxyphor and protoporphyrin IX, is an opportunity to quantify the consumption of oxygen during ROS generation, and this translates from in vitro to in vivo use. Emerging techniques, such as ion particle beams, spatial fractionation, and ultra-high dose rate FLASH radiotherapy, provide the motivation for these studies.

Conclusions

In vivo optical reporters of radiochemistry are quantitatively useful for comparing radiotherapy techniques, although their use comes at the cost of the unknown connection to the mechanisms of radiobiological damage. Still their lower measurement uncertainty, compared with biological response assay, makes them an invaluable tool. Linkage to DNA damage and biological damage is needed, and measures such as oxygen consumption serve as useful surrogate measures that translate to in vivo use.

Optical imaging for early detection of cervical cancer: state of the art and perspectives

Alisha Rahaman, Arpitha Anantharaju, Karthika Jeyachandran, Repala Manideep, Uttam M. Pal

Journal of Biomedical Optics, Vol. 28, Issue 08, 080902, (August 2023) https://doi.org/10.1117/1.JBO.28.8.080902

TOPICS: Cervical cancer, Cancer detection, Tissues, Raman spectroscopy, Cancer, Optical imaging, Cervix, Fluorescence imaging, Fluorescence, Imaging systems

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Review of imaging test phantoms

Liam Christie, Wenhan Zheng, William Johnson, Eric Marecki, James Heidrich, Jun Xia, Kwang W. Oh

Journal of Biomedical Optics, Vol. 28, Issue 08, 080903, (August 2023) https://doi.org/10.1117/1.JBO.28.8.080903

TOPICS: Tissues, Biomedical optics, Biological imaging, Magnetic resonance imaging, Tissue optics, Acoustics, Ultrasonography, Optical properties, Manufacturing, Biomedical applications

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Significance

Photoacoustic tomography has emerged as a prominent medical imaging technique that leverages its hybrid nature to provide deep penetration, high resolution, and exceptional optical contrast with notable applications in early cancer detection, functional brain imaging, drug delivery monitoring, and guiding interventional procedures. Test phantoms are pivotal in accelerating technology development and commercialization, specifically in photoacoustic (PA) imaging, and can be optimized to achieve significant advancements in PA imaging capabilities.

Aim

The analysis of material properties, structural characteristics, and manufacturing methodologies of test phantoms from existing imaging technologies provides valuable insights into their applicability to PA imaging. This investigation enables a deeper understanding of how phantoms can be effectively employed in the context of PA imaging.

Approach

Three primary categories of test phantoms (simple, intermediate, and advanced) have been developed to differentiate complexity and manufacturing requirements. In addition, four sub-categories (tube/channel, block, test target, and naturally occurring phantoms) have been identified to encompass the structural variations within these categories, resulting in a comprehensive classification system for test phantoms.

Results

Based on a thorough examination of literature and studies on phantoms in various imaging modalities, proposals have been put forth for the development of multiple PA-capable phantoms, encompassing considerations related to the material composition, structural design, and specific applications within each sub-category.

Conclusions

The advancement of novel and sophisticated test phantoms within each sub-category is poised to foster substantial progress in both the commercialization and development of PA imaging. Moreover, the continued refinement of test phantoms will enable the exploration of new applications and use cases for PA imaging.

Special Section on Seeing Inside Tissue with Optical Molecular Probes

Special Section Guest Editorial: Seeing Inside Tissue with Optical Molecular Probes

Nada N. Boustany, Mark Niedre, Manojit Pramanik

Journal of Biomedical Optics, Vol. 28, Issue 08, 082801, (August 2023) https://doi.org/10.1117/1.JBO.28.8.082801

TOPICS: Biomedical optics, Tissue optics, Contrast agents, Tissues, Nervous system, Fluorescence resonance energy transfer, Fluorescence, Tumors, Photoacoustic spectroscopy, Photoacoustic imaging

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Preclinical evaluation of molecularly targeted fluorescent probes in perfused amputated human limbs

Logan Bateman, Kendra Hebert, Jenna Nunziata, Samuel Streeter, Connor Barth, Lei Wang, Summer Gibbs, Eric Henderson

Journal of Biomedical Optics, Vol. 28, Issue 08, 082802, (January 2023) https://doi.org/10.1117/1.JBO.28.8.082802

TOPICS: Fluorophores, Nerve, Nervous system, Animal model studies, Lead, Adipose tissue, Tissues, Imaging systems, Muscles, Fluorescence imaging

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Barium sulfate and pigment admixture for photoacoustic and x-ray contrast imaging of the gut

Hailey I. Kilian, Huijuan Zhang, Mohammad Mahdi Shiraz Bhurwani, Anoop M. Nilam, Daewoon Seong, Mansik Jeon, Ciprian N. Ionita, Jun Xia, Jonathan F. Lovell

Journal of Biomedical Optics, Vol. 28, Issue 08, 082803, (February 2023) https://doi.org/10.1117/1.JBO.28.8.082803

TOPICS: Pigments, Barium, Dyes, X-rays, X-ray imaging, Photoacoustic imaging, Photoacoustic spectroscopy, Contrast agents, Biomedical optics, Mixtures

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Multiscale photoacoustic tomography using reversibly switchable thermochromics

Chenshuo Ma, Xiao Kuang, Maomao Chen, Luca Menozzi, Laiming Jiang, Qifa Zhou, Yu Shrike Zhang, Junjie Yao

Journal of Biomedical Optics, Vol. 28, Issue 08, 082804, (February 2023) https://doi.org/10.1117/1.JBO.28.8.082804

TOPICS: Photoacoustic spectroscopy, Photoacoustic tomography, Acquisition tracking and pointing, Switching, Signal detection, Tissues, Color, Temperature metrology, In vivo imaging, Absorption

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In vivo quantitative photoacoustic monitoring of corticosteroid-induced vasoconstriction

Donggyu Kim, Joongho Ahn, Eunwoo Park, Jin Young Kim, Chulhong Kim

Journal of Biomedical Optics, Vol. 28, Issue 08, 082805, (February 2023) https://doi.org/10.1117/1.JBO.28.8.082805

TOPICS: Skin, Blood vessels, Biological imaging, Photoacoustic spectroscopy, Imaging systems, In vivo imaging, Capillaries, Visualization, Tissue optics, Biomedical applications

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Dual probe difference specimen imaging for prostate cancer margin assessment

Marcus J. Kwon, Broderick J. House, Connor W. Barth, Allison Solanki, Jocelyn A. Jones, Scott C. Davis, Summer L. Gibbs

Journal of Biomedical Optics, Vol. 28, Issue 08, 082806, (April 2023) https://doi.org/10.1117/1.JBO.28.8.082806

TOPICS: Tumors, Adipose tissue, Prostate cancer, Prostate, Muscles, Tissues, Resection, Antibodies, Fluorescence, Cancer

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Significance

Positive margin status due to incomplete removal of tumor tissue during radical prostatectomy for high-risk localized prostate cancer requires reoperation or adjuvant therapy, which increases morbidity and mortality. Adverse effects of prostate cancer treatments commonly include erectile dysfunction, urinary incontinence, and bowel dysfunction, making successful initial curative prostatectomy imperative.

Aim

Current intraoperative tumor margin assessment is largely limited to frozen section analysis, which is a lengthy, labor-intensive process that is obtrusive to the clinical workflow within the operating room (OR). Therefore, a rapid method for prostate cancer margin assessment in the OR could improve outcomes for patients.

Approach

Dual probe difference specimen imaging (DDSI), which uses paired antibody-based probes that are labeled with spectrally distinct fluorophores, was shown herein for prostate cancer margin assessment. The paired antibody-based probes consisted of a targeted probe to prostate-specific membrane antigen (PSMA) and an untargeted probe, which were used as a cocktail to stain resected murine tissue specimens including prostate tumor, adipose, muscle, and normal prostate. Ratiometric images (i.e., DDSI) of the difference between targeted and untargeted probe uptake were calculated and evaluated for accuracy using receiver operator characteristic curve analysis with area under the curve values used to evaluate the utility of the DDSI method to detect PSMA positive prostate cancer.

Results

Targeted and untargeted probe uptake was similar between the high and low PSMA expressing tumor due to nonspecific probe uptake after topical administration. The ratiometric DDSI approach showed substantial contrast difference between the PSMA positive tumors and their respective normal tissues (prostate, adipose, muscle). Furthermore, DDSI showed substantial contrast difference between the high PSMA expressing tumors and the minimally PSMA expressing tumors due to the ratiometric correction for the nonspecific uptake patterns in resected tissues.

Conclusions

Previous work has shown that ratiometic imaging has strong predictive value for breast cancer margin status using topical administration. Translation of the ratiometric DDSI methodology herein from breast to prostate cancers demonstrates it as a robust, ratiometric technique that provides a molecularly specific imaging modality for intraoperative margin detection. Using the validated DDSI protocol on resected prostate cancers permitted rapid and accurate assessment of PSMA status as a surrogate for prostate cancer margin status. Future studies will further evaluate the utility of this technology to quantitatively characterize prostate margin status using PSMA as a biomarker.

Ensemble and single-particle level fluorescent fine-tuning of carbon dots via positional changes of amines toward “supervised” oral microbiome sensing

Fatemeh Ostadhossein, Parikshit Moitra, Maha Alafeef, Dinabandhu Sar, Shannon D’Souza, Lily Benig, Michael Nelappana, Xuedong Huang, Julio Soares, Kai Zhang, Dipanjan Pan

Journal of Biomedical Optics, Vol. 28, Issue 08, 082807, (July 2023) https://doi.org/10.1117/1.JBO.28.8.082807

TOPICS: Cadmium sulfide, Fluorescence, Bacteria, Materials properties, Photoluminescence, Nanoparticles, Proteins, Nitrogen, X-ray photoelectron spectroscopy, Transmission electron microscopy

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Significance

Carbon dots (CDs) have attracted a host of research interest in recent years mainly due to their unique photoluminescence (PL) properties that make them applicable in various biomedical areas, such as imaging and image-guided therapy. However, the real mechanism underneath the PL is a subject of wide controversy and can be investigated from various angles.

Aim

Our work investigates the effect of the isomeric nitrogen position as the precursor in the synthesis of CDs by shedding light on their photophysical properties on the single particles and ensemble level.

Approach

To this end, we adopted five isomers of diaminopyridine (DAP) and urea as the precursors and obtained CDs during a hydrothermal process. The various photophysical properties were further investigated in depth by mass spectroscopy. CD molecular frontier orbital analyses aided us in justifying the fluorescence emission profile on the bulk level as well as the charge transfer processes. As a result of the varying fluorescent responses, we indicate that these particles can be utilized for machine learning (ML)-driven sensitive detection of oral microbiota. The sensing results were further supported by density functional theoretical calculations and docking studies.

Results

The generating isomers have a significant effect on the overall photophysical properties at the bulk/ensembled level. On the single-particle level, although some of the photophysical properties such as average intensity remained the same, the overall differences in brightness, photo-blinking frequency, and bleaching time between the five samples were conceived. The various photophysical properties could be explained based on the different chromophores formed during the synthesis. Overall, an array of CDs was demonstrated herein to achieve ∼100 % separation efficacy in segregating a mixed oral microbiome culture in a rapid (<0.5 h), high-throughput manner with superior accuracy.

Conclusions

We have indicated that the PL properties of CDs can be regulated by the precursors’ isomeric position of nitrogen. We emancipated this difference in a rapid method relying on ML algorithms to segregate the dental bacterial species as biosensors.

Förster resonance energy transfer efficiency measurements on vinculin tension sensors at focal adhesions using a simple and cost-effective setup

Camille Dubois, Ludivine Houel-Renault, Marie Erard, Nada Boustany, Nathalie Westbrook

Journal of Biomedical Optics, Vol. 28, Issue 08, 082808, (July 2023) https://doi.org/10.1117/1.JBO.28.8.082808

TOPICS: Fluorescence resonance energy transfer, Focal adhesions, Calibration, Sensors, Tunable filters, Resonance energy transfer, Optical filters, Cameras, Photobleaching, Energy efficiency

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Significance

Forces inside cells play a fundamental role in tissue growth, affecting important processes such as cancer cell migration or tissue repair after injury. Förster resonance energy transfer (FRET)-based tension sensors are a remarkable tool for studying these forces and should be made easier to use.

Aim

We prove that absolute FRET efficiency can be measured on a simple setup, an order of magnitude more cost-effective than a standard FRET microscopy setup, by applying it to vinculin tension sensors (VinTS) at the focal adhesions of live CHO-K1 cells.

Approach

Our setup located at Université Paris-Saclay acquires donor and acceptor fluorescence in parallel on two low-cost CMOS cameras and uses two LEDs for rapid switching of the excitation wavelength at a reduced cost. The calibration required to extract FRET efficiency was achieved using a single construct (TSMod). FRET efficiencies were measured for VinTS and the tail-less control VinTL, lacking the actin-binding domain of vinculin. Measurements were confirmed on the same cell type using a more standard intensity-based setup located at Rutgers University.

Results

The average FRET efficiency of VinTS (22.0 % ± 4 % ) over more than 10,000 focal adhesions is significantly lower (p < ^{10 − 6}) than that of VinTL (30.4 % ± 5 % ), our control that is insensitive to force, in agreement with the force exerted on vinculin at focal adhesions. Attachment of the CHO-K1 cells on fibronectin decreases FRET efficiency, thus increasing the force, compared with poly-lysine. FRET efficiency for the VinTL control is consistent with all measurements currently available in the literature, confirming the validity of our measurements and hence of our simpler setup.

Conclusions

Force measurements, resolved spatially inside a cell, can be achieved using FRET-based tension sensors with a cost effective intensity-based setup. This will facilitate combining FRET with techniques for applying controlled forces such as optical tweezers.

Clinical assessment of a low-cost, hand-held, smartphone-attached intraoral imaging probe for 5-aminolevulinic acid photodynamic therapy monitoring and guidance

Shakir Khan, Bofan Song, Srivalleesha Mallidi, Shaobai Li, Hui Liu, M. A. Bilal Hussain, Shaista Siddiqui, Amjad P. Khan, Kafil Akhtar, Shahid Ali Siddiqui, Syed Abrar Hasan, Colin Hopper, Stephen G. Bown, Rongguang Liang, Tayyaba Hasan, Jonathan P. Celli

Journal of Biomedical Optics, Vol. 28, Issue 08, 082809, (July 2023) https://doi.org/10.1117/1.JBO.28.8.082809

TOPICS: Photodynamic therapy, Tissues, Image segmentation, Cancer, Oncology, Biomedical optics, Tumors, Imaging systems, Light emitting diodes, Collagen

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Significance

India has one of the highest rates of oral squamous cell carcinoma (OSCC) in the world, with an incidence of 15 per 100,000 and more than 70,000 deaths per year. The problem is exacerbated by a lack of medical infrastructure and routine screening, especially in rural areas. New technologies for oral cancer detection and timely treatment at the point of care are urgently needed.

Aim

Our study aimed to use a hand-held smartphone-coupled intraoral imaging device, previously investigated for autofluorescence (auto-FL) diagnostics adapted here for treatment guidance and monitoring photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) fluorescence (FL).

Approach

A total of 12 patients with 14 buccal mucosal lesions having moderately/well-differentiated micro-invasive OSCC lesions (<2 cm diameter and <5 mm depth) were systemically (in oral solution) administered three doses of 20 mg / kg ALA (total 60 mg / kg). Lesion site PpIX and auto-FL were imaged using the multichannel FL and polarized white-light oral cancer imaging probe before/after ALA administration and after light delivery (fractionated, total 100 J / cm² of 635 nm red LED light).

Results

The handheld device was conducive for access to lesion site images in the oral cavity. Segmentation of ratiometric images in which PpIX FL is mapped relative to auto-FL enabled improved demarcation of lesion boundaries relative to PpIX alone. A relative FL (R-value) threshold of 1.4 was found to segment lesion site PpIX production among the patients with mild to severe dysplasia malignancy. The segmented lesion size is well correlated with ultrasound findings. Lesions for which R-value was >1.65 at the time of treatment were associated with successful outcomes.

Conclusion

These results indicate the utility of a low-cost, handheld intraoral imaging probe for image-guided PDT and treatment monitoring while also laying the groundwork for an integrated approach, combining cancer screening and treatment with the same hardware.

General

Multivariate analysis of breast tissue using optical parameters extracted from a combined time-resolved fluorescence and diffuse reflectance system for tumor margin detection

Erica Dao, Gabriela Gohla, Phillip Williams, Peter Lovrics, Fares Badr, Qiyin Fang, Thomas Farrell, Michael Farquharson

Journal of Biomedical Optics, Vol. 28, Issue 08, 085001, (August 2023) https://doi.org/10.1117/1.JBO.28.8.085001

TOPICS: Tumors, Tissues, Adipose tissue, Breast, Tissue optics, Modeling, Biological samples, Reflectivity, Cancer detection, Principal component analysis

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Depth-dependent attenuation and backscattering characterization of optical coherence tomography by stationary iterative method

Yaning Wang, Shuwen Wei, Jin U. Kang

Journal of Biomedical Optics, Vol. 28, Issue 08, 085002, (August 2023) https://doi.org/10.1117/1.JBO.28.8.085002

TOPICS: Signal attenuation, Optical coherence tomography, Backscatter, Tissues, Signal intensity, Monte Carlo methods, Biological samples, Scattering, Optical properties, Attenuation

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Significance

Extracting optical properties of tissue [e.g., the attenuation coefficient (μ) and the backscattering fraction] from the optical coherence tomography (OCT) images is a valuable tool for parametric imaging and related diagnostic applications. Previous attenuation estimation models depend on the assumption of the uniformity of the backscattering fraction (R) within layers or whole samples, which does not accurately represent real-world conditions.

Aim

Our aim is to develop a robust and accurate model that calculates depth-wise values of attenuation and backscattering fractions simultaneously from OCT signals. Furthermore, we aim to develop an attenuation compensation model for OCT images that utilizes the optical properties we obtained to improve the visual representation of tissues.

Approach

Using the stationary iteration method under suitable constraint conditions, we derived the approximated solutions of μ and R on a single scattering model. During the iteration, the estimated value of μ can be rectified by introducing the large variations of R, whereas the small ones were automatically ignored. Based on the calculation of the structure information, the OCT intensity with attenuation compensation was deduced and compared with the original OCT profiles.

Results

The preliminary validation was performed in the OCT A-line simulation and Monte Carlo modeling, and the subsequent experiment was conducted on multi-layer silicone-dye-TiO₂ phantoms and ex vivo cow eyes. Our method achieved robust and precise estimation of μ and R for both simulated and experimental data. Moreover, corresponding OCT images with attenuation compensation provided an improved resolution over the entire imaging range.

Conclusions

Our proposed method was able to correct the estimation bias induced by the variations of R and provided accurate depth-resolved measurements of both μ and R simultaneously. The method does not require prior knowledge of the morphological information of tissue and represents more real-life tissues. Thus, it has the potential to help OCT imaging based disease diagnosis of complex and multi-layer biological tissue.

Spatial averaging method based on adaptive weight for imaging photoplethysmography

JongSong Ryu, HyonSam Ryu, Shili Liang, SunChol Hong, Yueqi Lian, Zong Zheng

Journal of Biomedical Optics, Vol. 28, Issue 08, 085003, (August 2023) https://doi.org/10.1117/1.JBO.28.8.085003

TOPICS: Pulse signals, Signal to noise ratio, Databases, Skin, Interference (communication), Biomedical optics, Video, Heart, Photoplethysmography, Cameras

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Imaging

Evaluating the identification of the extent of gastric cancer by over-1000 nm near-infrared hyperspectral imaging using surgical specimens

Tomohiro Mitsui, Akino Mori, Toshihiro Takamatsu, Tomohiro Kadota, Konosuke Sato, Ryodai Fukushima, Kyohei Okubo, Masakazu Umezawa, Hiroshi Takemura, Hideo Yokota, Takeshi Kuwata, Takahiro Kinoshita, Hiroaki Ikematsu, Tomonori Yano, Shin Maeda, Kohei Soga

Journal of Biomedical Optics, Vol. 28, Issue 08, 086001, (August 2023) https://doi.org/10.1117/1.JBO.28.8.086001

TOPICS: Cancer, Tumors, Tissues, Hyperspectral imaging, Near infrared, Resection, Endoscopy, Natural surfaces, Surgery, Biological samples

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Two-stage classification strategy for breast cancer diagnosis using ultrasound-guided diffuse optical tomography and deep learning

Menghao Zhang, Shuying Li, Minghao Xue, Quing Zhu

Journal of Biomedical Optics, Vol. 28, Issue 08, 086002, (August 2023) https://doi.org/10.1117/1.JBO.28.8.086002

TOPICS: Histograms, Tumor growth modeling, Image classification, Breast cancer, Feature extraction, Breast, Data modeling, Image restoration, Deep learning, Education and training

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Smartphone-based dual radiometric fluorescence and white-light imager for quantification of protoporphyrin IX in skin

Alberto J. Ruiz, Richard Allen, Mia K. Giallorenzi, Kimberley S. Samkoe, M. Shane Chapman, Brian W. Pogue

Journal of Biomedical Optics, Vol. 28, Issue 08, 086003, (August 2023) https://doi.org/10.1117/1.JBO.28.8.086003

TOPICS: Imaging systems, Photodynamic therapy, Tunable filters, Skin, Blood, Fluorescence, Photobleaching, Light emitting diodes, Cameras, Image filtering

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Significance

The quantification of protoporphyrin IX (PpIX) in skin can be used to study photodynamic therapy (PDT) treatments, understand porphyrin mechanisms, and enhance preoperative mapping of non-melanoma skin cancers.

Aim

We aim to develop a smartphone-based imager for performing simultaneous radiometric fluorescence (FL) and white light (WL) imaging to study the baseline levels, accumulation, and photobleaching of PpIX in skin.

Approach

A smartphone-based dual FL and WL imager (sDUO) is introduced alongside new radiometric calibration methods for providing SI-units of measurements in both pre-clinical and clinical settings. These radiometric measurements and corresponding PpIX concentration estimations are applied to clinical measurements to understand mechanistic differences between PDT treatments, accumulation differences between normal tissue and actinic keratosis lesions, and the correlation of photosensitizer concentrations to treatment outcomes.

Results

The sDUO alongside the developed methods provided radiometric FL measurements (nW / cm²) with a demonstrated sub nanomolar PpIX sensitivity in 1% intralipid phantoms. Patients undergoing PDT treatment of actinic keratosis (AK) lesions were imaged, capturing the increase and subsequent decrease in FL associated with the incubation and irradiation timepoints of lamp-based PDT. Furthermore, the clinical measurements showed mechanistic differences in new daylight-based treatment modalities alongside the selective accumulation of PpIX within AK lesions. The use of the radiometric calibration enabled the reporting of detected PpIX FL in units of nW / cm² with the use of liquid phantom measurements allowing for the estimation of in-vivo molar concentrations of skin PpIX.

Conclusions

The phantom, pre-clinical, and clinical measurements demonstrated the capability of the sDUO to provide quantitative measurements of PpIX FL. The results demonstrate the use of the sDUO for the quantification of PpIX accumulation and photobleaching in a clinical setting, with implications for improving the diagnosis and treatment of various skin conditions.

Customizable optical tissue phantom platform for characterization of fluorescence imaging device sensitivity

Christopher Gibson, Arcturus Phoon, Ralph S. DaCosta

Journal of Biomedical Optics, Vol. 28, Issue 08, 086004, (August 2023) https://doi.org/10.1117/1.JBO.28.8.086004

TOPICS: Tissues, Fluorophores, Imaging devices, Breast, Adipose tissue, Connective tissue, Tissue optics, Absorption, Polydimethylsiloxane, Semiconducting wafers

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Microscopy

Three-dimensional angular scattering simulations inform analysis of scattering from single cells

Kaitlin J. Dunn, Andrew J. Berger

Journal of Biomedical Optics, Vol. 28, Issue 08, 086501, (August 2023) https://doi.org/10.1117/1.JBO.28.8.086501

TOPICS: Signal to noise ratio, Simulations, Mie scattering, Scattering, Light scattering, Quantum reading, Interference (communication), Mitochondria, Quantum numbers, Quantum noise

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Sensing

Noninvasive blood glucose sensing by secondary speckle pattern artificial intelligence analyses

Deep Pal, Amitesh Kumar, Nave Avraham, Yoram Eisenbach, Yevgeny Beiderman, Sergey Agdarov, Yafim Beiderman, Zeev Zalevsky

Journal of Biomedical Optics, Vol. 28, Issue 08, 087001, (August 2023) https://doi.org/10.1117/1.JBO.28.8.087001

TOPICS: Glucose, Blood, Magnetism, Speckle pattern, Data modeling, Education and training, Skin, Speckle, Plasma, Reflection

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Significance

Diabetes is a prevalent disease worldwide that can cause severe health problems. Accurate blood glucose detection is crucial for diabetes management, and noninvasive methods can be more convenient and less painful than traditional finger-prick methods.

Aim

We aim to report a noncontact speckle-based blood glucose measurement system that utilizes artificial intelligence (AI) data processing to improve glucose detection accuracy. The study also explores the influence of an alternating current (AC) induced magnetic field on the sensitivity and selectivity of blood glucose detection.

Approach

The proposed blood glucose sensor consists of a digital camera, an AC-generated magnetic field source, a laser illuminating the subject’s finger, and a computer. A magnetic field is applied to the finger, and a camera records the speckle patterns generated by the laser light reflected from the finger. The acquired video data are preprocessed for machine learning (ML) and deep neural networks (DNNs) to classify blood plasma glucose levels. The standard finger-prick method is used as a reference for blood glucose level classification.

Results

The study found that the noncontact speckle-based blood glucose measurement system with AI data processing allows for the detection of blood plasma glucose levels with high accuracy. The ML approach gives better results than the tested DNNs as the proposed data preprocessing is highly selective and efficient.

Conclusions

The proposed noncontact blood glucose sensing mechanism utilizing AI data processing and a magnetic field can potentially improve glucose detection accuracy, making it more convenient and less painful for patients. The system also allows for inexpensive blood glucose sensing mechanisms and fast blood glucose screening. The results suggest that noninvasive methods can improve blood glucose detection accuracy, which can have significant implications for diabetes management. Investigations involving representative sampling data, including subjects of different ages, gender, race, and health status, could allow for further improvement.

Porcine vocal fold elasticity evaluation using Brillouin spectroscopy

Vsevolod Cheburkanov, Ethan Keene, Jason Pipal, Michael Johns, Brian Applegate, Vladislav Yakovlev

Journal of Biomedical Optics, Vol. 28, Issue 08, 087002, (August 2023) https://doi.org/10.1117/1.JBO.28.8.087002

TOPICS: Elasticity, Spectroscopy, Tissues, Imaging spectroscopy, Materials properties, Biological samples, Iodine, Scattering, Acetone, Viscoelasticity

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