Autofluorescence Detection Research Articles

Smartphone offers on-site soil microbiome profiling

A low-cost, portable platform based on autofluorescence detection and machine learning can quickly identify bacterial species to assess soil health.

A smartphone-based approach for comprehensive soil microbiome profiling.

The soil microbiome is crucial for nutrient cycling, health, and plant growth. This study presents a smartphone-based approach as a low-cost and portable alternative to traditional methods for classifying bacterial species and characterizing microbial communities in soil samples. By harnessing bacterial autofluorescence detection and machine learning algorithms, the platform achieved an average accuracy of 88% in distinguishing common soil-related bacterial species despite the lack of biomarkers, nucleic acid amplification, or gene sequencing. Furthermore, it successfully identified dominant species within various bacterial mixtures with an accuracy of 76% and three-level soil health identification at an accuracy of 80%-82%, providing insights into microbial community dynamics. The influence of other soil conditions (pH and moisture) was relatively minor, showcasing the platform's robustness. Various field soil samples were also tested with this platform at 80% accuracy compared with the laboratory analyses, demonstrating the practicality and usability of this approach for on-site soil analysis. This study highlights the potential of the smartphone-based system as a valuable tool for soil assessment, microbial monitoring, and environmental management.

Developing a Portable Autofluorescence Detection System and Its Application in Biological Samples.

Advanced glycation end-products (AGEs) are complex compounds closely associated with several chronic diseases, especially diabetes mellitus (DM). Current methods for detecting AGEs are not suitable for screening large populations, or for long-term monitoring. This paper introduces a portable autofluorescence detection system that measures the concentration of AGEs in the skin based on the fluorescence characteristics of AGEs in biological tissues. The system employs a 395 nm laser LED to excite the fluorescence of AGEs, and uses a photodetector to capture the fluorescence intensity. A model correlating fluorescence intensity with AGEs concentration facilitates the detection of AGEs levels. To account for the variation in optical properties of different individuals' skin, the system includes a 520 nm light source for calibration. The system features a compact design, measuring only 60 mm × 50 mm × 20 mm, and is equipped with a miniature STM32 module for control and a battery for extended operation, making it easy for subjects to wear. To validate the system's effectiveness, it was tested on 14 volunteers to examine the correlation between AGEs and glycated hemoglobin, revealing a correlation coefficient of 0.49. Additionally, long-term monitoring of AGEs' fluorescence and blood sugar levels showed a correlation trend exceeding 0.95, indicating that AGEs reflect changes in blood sugar levels to some extent. Further, by constructing a multivariate predictive model, the study also found that AGEs levels are correlated with age, BMI, gender, and a physical activity index, providing new insights for predicting AGEs content and blood sugar levels. This research supports the early diagnosis and treatment of chronic diseases such as diabetes, and offers a potentially useful tool for future clinical applications.

Multimodal Multiphoton Tomography with a Compact Femtosecond Fiber Laser

Multiphoton tomography (MPT) based on near infrared (NIR) femtosecond laser technology has become a versatile high-resolution clinical and research imaging tool. We report on multimodal MPT with the air-cooled fiber laser tomograph MPTcompact. The ultracompact passively mode-locked erbium-doped 50/80 MHz laser operating at 780 nm is directly integrated into the 360° imaging head mounted on a flexible mechanical arm. The tomograph provides optical biopsies with subcellular resolution and optical metabolic imaging capability based on two-photon autofluorescence (AF), second harmonic generation, fluorescence lifetime imaging (FLIM) by time-correlated single photon counting with 250 ps temporal resolution, reflectance confocal microscopy, and white LED light CMOS camera imaging. For the first time, NIR femtosecond laser pulses have been used on human skin to realize simultaneous one-photon confocal imaging and two-photon imaging. Most useful information is provided by the two-photon excited intratissue AF of the coenzymes NAD(P)H and flavins. The signals of both types of coenzymes can be separated by FLIM. Furthermore, the free and protein-bound forms can be distinguished by time-resolved AF detection because the protein-bound NADH has one order higher AF lifetime than free (non-bound) NADH. The tomograph contains onboard storage batteries so that it can operate for up to a few hours independently from external power supply. Applications include in vivo cancer detection and in situ evaluation of anti-aging drugs and pharmaceuticals. The tomograph MPTcompact has been successfully tested in a clinical multicenter study for the diagnosis of malignant melanoma on 100 patients with suspicious pigmented lesions. MPT has the potential to realize non-invasive high-resolution label-free in vivo histology within minutes and, therefore, to reduce the number of physically taken biopsies.

Retinal atrophy, inflammation, phagocytic and metabolic disruptions develop in the MerTK-cleavage-resistant mouse model.

In the eye, cells from the retinal pigment epithelium (RPE) facing the neurosensory retina exert several functions that are all crucial for long-term survival of photoreceptors (PRs) and vision. Among those, RPE cells phagocytose under a circadian rhythm photoreceptor outer segment (POS) tips that are constantly subjected to light rays and oxidative attacks. The MerTK tyrosine kinase receptor is a key element of this phagocytic machinery required for POS internalization. Recently, we showed that MerTK is subjected to the cleavage of its extracellular domain to finely control its function. In addition, monocytes in retinal blood vessels can migrate inside the inner retina and differentiate into macrophages expressing MerTK, but their role in this context has not been studied yet. We thus investigated the ocular phenotype of MerTK cleavage-resistant (MerTKCR) mice to understand the relevance of this characteristic on retinal homeostasis at the RPE and macrophage levels. MerTKCR retinae appear to develop and function normally, as observed in retinal sections, by electroretinogram recordings and optokinetic behavioral tests. Monitoring of MerTKCR and control mice between the ages of 3 and 18 months showed the development of large degenerative areas in the central retina as early as 4 months when followed monthly by optical coherence tomography (OCT) plus fundus photography (FP)/autofluorescence (AF) detection but not by OCT alone. The degenerative areas were associated with AF, which seems to be due to infiltrated macrophages, as observed by OCT and histology. MerTKCR RPE primary cultures phagocytosed less POS in vitro, while in vivo, the circadian rhythm of POS phagocytosis was deregulated. Mitochondrial function and energy production were reduced in freshly dissected RPE/choroid tissues at all ages, thus showing a metabolic impairment not present in macrophages. RPE anomalies were detected by electron microscopy, including phagosomes retained in the apical area and vacuoles. Altogether, this new mouse model displays a novel phenotype that could prove useful to understanding the interplay between RPE and PRs in inflammatory retinal degenerations and highlights new roles for MerTK in the regulation of the energetic metabolism and the maintenance of the immune privilege in the retina.

In situ observation of cartilage matrix based on two-photon fluorescence microscopy

Articular cartilage lesions remain a major challenge for clinicians and researchers. Several techniques, such as histological scoring, magnetic resonance imaging, and tissue section staining, are available for detecting cartilage degeneration and lesions and evaluating cartilage repairs. Nevertheless, these methods are complex and have numerous influencing factors, which may present obstacles to efficient communication between studies. In this study, we developed a fluorescence observation system that integrated a two-photon laser scanning confocal microscope (TPLSCM) with the second-harmonic generation (SHG) of a cartilage matrix. The observation system enabled the detection of autofluorescence emitted by the cartilage matrix without species specificity, facilitating both qualitative and quantitative analyses of the cartilage matrix. Notably, this observation could be applied three-dimensionally to a fresh specimen in situ up to a depth of 300 μm, obviating the need for traditional histological fixation, slicing, or staining. Furthermore, using this observation system, we reconstructed a three-dimensional (3D) image and a 3D model of the cartilage matrix. The utilization of the 3D fluorescence model may serve as a dependable option for the fabrication of cartilage matrix biomimetic scaffolds in future studies.

TOETVA parathyroid autofluorescence detection: hANDY-i endoscopy attachment.

Treatment options for thyroid pathologies have expanded to include scarless and remote access methods such as the transoral endoscopic thyroidectomy vestibular approach (TOETVA). Currently, no standardized methods exist for locating parathyroid glands (PGs) in patients undergoing TOETVA, which can lead to parathyroid injury and subsequent hypocalcemia. This early feasibility study describes and evaluates the hANDY-i endoscopic attachment for detecting PGs in transoral thyroidectomy. We used a prototype parathyroid autofluorescence imager (hANDY-i) that was mounted to a 10-mm 0-degree endoscope. The device delivers a split screen view of Red-green-blue (RGB) and near-infrared autofluorescence (NIRAF) which allows for simultaneous anatomical localization and fluorescence visualization of PGs during endoscopic thyroid dissection. One cadaveric case and two patient cases were included in this study. The endoscopic hANDY-i imaging system successfully visualized PGs during all procedures. The ability to leverage parathyroid autofluorescence during TOETVA may lead to improved PG localization and preservation. Further human studies are needed to assess its effect on postoperative hypocalcemia and hypoparathyroidism.

Intraoperative microscopic autofluorescence detection and characterization in brain tumors using stimulated Raman histology and two-photon fluorescence.

The intrinsic autofluorescence of biological tissues interferes with the detection of fluorophores administered for fluorescence guidance, an emerging auxiliary technique in oncological surgery. Yet, autofluorescence of the human brain and its neoplasia is sparsely examined. This study aims to assess autofluorescence of the brain and its neoplasia on a microscopic level by stimulated Raman histology (SRH) combined with two-photon fluorescence. With this experimentally established label-free microscopy technique unprocessed tissue can be imaged and analyzed within minutes and the process is easily incorporated in the surgical workflow. In a prospective observational study, we analyzed 397 SRH and corresponding autofluorescence images of 162 samples from 81 consecutive patients that underwent brain tumor surgery. Small tissue samples were squashed on a slide for imaging. SRH and fluorescence images were acquired with a dual wavelength laser (790 nm and 1020 nm) for excitation. In these images tumor and non-tumor regions were identified by a convolutional neural network that reliably differentiates between tumor, healthy brain tissue and low quality SRH images. The identified areas were used to define regions.of- interests (ROIs) and the mean fluorescence intensity was measured. In healthy brain tissue, we found an increased mean autofluorescence signal in the gray (11.86, SD 2.61, n=29) compared to the white matter (5.99, SD 5.14, n=11, p<0.01) and in the cerebrum (11.83, SD 3.29, n=33) versus the cerebellum (2.82, SD 0.93, n=7, p<0.001), respectively. The signal of carcinoma metastases, meningiomas, gliomas and pituitary adenomas was significantly lower (each p<0.05) compared to the autofluorescence in the cerebrum and dura, and significantly higher (each p<0.05) compared to the cerebellum. Melanoma metastases were found to have a higher fluorescent signal (p<0.01) compared to cerebrum and cerebellum. In conclusion we found that autofluorescence in the brain varies depending on the tissue type and localization and differs significantly among various brain tumors. This needs to be considered for interpreting photon signal during fluorescence-guided brain tumor surgery.

Label-free, fast, 2-photon volume imaging of the organization of neurons and glia in the enteric nervous system.

The enteric nervous system (ENS), sometimes referred to as a "second brain" is a quasi-autonomous nervous system, made up of interconnected plexuses organized in a mesh-like network lining the gastrointestinal tract. Originally described as an actor in the regulation of digestion, bowel contraction, and intestinal secretion, the implications of the ENS in various central neuropathologies has recently been demonstrated. However, with a few exceptions, the morphology and pathologic alterations of the ENS have mostly been studied on thin sections of the intestinal wall or, alternatively, in dissected explants. Precious information on the three-dimensional (3-D) architecture and connectivity is hence lost. Here, we propose the fast, label-free 3-D imaging of the ENS, based on intrinsic signals. We used a custom, fast tissue-clearing protocol based on a high refractive-index aqueous solution to increase the imaging depth and allow us the detection of faint signals and we characterized the autofluorescence (AF) from the various cellular and sub-cellular components of the ENS. Validation by immunofluorescence and spectral recordings complete this groundwork. Then, we demonstrate the rapid acquisition of detailed 3-D image stacks from unlabeled mouse ileum and colon, across the whole intestinal wall and including both the myenteric and submucosal enteric nervous plexuses using a new spinning-disk two-photon (2P) microscope. The combination of fast clearing (less than 15 min for 73% transparency), AF detection and rapid volume imaging [less than 1 min for the acquisition of a z-stack of 100 planes (150*150 μm) at sub-300-nm spatial resolution] opens up the possibility for new applications in fundamental and clinical research.

Research and Design of Bacterial Autofluorescence Detection Device

Research and Design of Bacterial Autofluorescence Detection Device

Label-Free Enhancement of Adrenal Gland Visualization Using Near-Infrared Autofluorescence for Surgical Guidance.

During adrenalectomy, surgeons have traditionally relied on their subjective visual skills to distinguish adrenal glands (AGs) from retroperitoneal fat and surrounding structures, while ultrasound and exogenous contrast agents have been employed for intraoperative AG visualization, all of which have their limitations. We present a novel label-free approach that uses near-infrared autofluorescence (NIRAF) detection, which demonstrates potential for enhanced intraoperative AG visualization and efficient tumor resection during adrenalectomies. Patients undergoing adrenalectomy or nephrectomy were enrolled for this feasibility study. NIRAF emitted beyond 800nm was detected in vivo from AGs and surrounding tissues during open adrenalectomies or nephrectomies. NIRAF was also measured ex vivo in excised AGs following robotic adrenalectomies. NIRAF images of tissues were captured using near-infrared (NIR) camera systems, whereas NIRAF intensities were recorded concurrently using fiber-optic probe-based NIR devices. Normalized NIRAF intensities (expressed as mean ± standard error) were analyzed and compared. Among the 55 enrolled patients, NIRAF intensity was elevated significantly for AGs versus retroperitoneal fat and other structures. NIR images of AGs also revealed a distinct demarcation of NIRAF between adrenal cortex and other periadrenal structures. NIRAF intensity in AGs was decreased markedly in malignant adrenal tumors, while benign adrenal cortical tumors and healthy adrenal cortex exhibited the strongest NIRAF levels. Our preliminary findings indicate that NIRAF detection could be a promising label-free technology to enhance intraoperative AG visualization and holds immense potential for effective tumor demarcation during cortical-sparing adrenalectomies or adrenal-conserving surgeries.

Silicon Photomultiplier-A High Dynamic Range, High Sensitivity Sensor for Bio-Photonics Applications.

This work is an overview of silicon photomultipliers (SiPMs) with a view to defining their importance for bio-photonic and clinical applications. SiPMs are benchmarked against other common photodetectors, namely, PIN diodes and avalanche photodetectors (APDs) and are compared with respect to important circuit design parameters. It will be shown that careful selection of the design bias voltage, overvoltage, gain defining components and device integration to micro-optics can allow SiPM detectors to achieve considerable sensitivity for auto-fluorescence (AF) detection and a wide dynamic range at low optical powers (~1 pW to ~4 μW). The SiPM has a manageable bias voltage (~25 V to ~30 V DC) for systems integration, and with optimised sensitivity it will enhance bio-photonic research in the area of AF to detect intraoperatively, for example, brain tumour margins.

The use of near-infrared autofluorescence during total laryngectomy with hemi- or total thyroidectomy.

The aim of this study is to describe the use of near-infrared autofluorescence (NIR-AF) to identify and preserve parathyroid glands (PGs) in a group of patients with advanced hypopharyngeal/laryngeal cancer undergone total (pharyngo)laryngectomy with hemi- or total thyroidectomy. At San Raffaele Hospital, Milan (Italy), from January 2021 to May 2021, 7 patients affected by cT4a laryngeal squamous cell carcinoma (SCC) underwent surgery using an autofluorescence detection system (Fluobeam-Fluoptics®). For proper surgical planning, the demolition phase envisaged extension of the intervention to 4 hemithyroidectomies and 3 total thyroidectomies associated, respectively, with homolateral or bilateral CCND. Serum calcium, ionized calcium, and parathyroid hormone (PTH) levels at post-operative day (POD) 1 and 2 and at 2weeks after surgery were monitored. Finally, we compared the data obtained with a cohort of patients who underwent surgery without the adoption of NIR-AF. With the use of NIR-AF, 18/20 PGs were identified, of which 7/18 were preserved exclusively thanks to the use of autoflorescence. The technique also made it possible to identify and isolate three PGs from the surgical specimen, which were subsequently transplanted only after intraoperative histological confirmation. On POD-1, 3/7 patients (42.8%) were hypocalcemic; on POD-2 and after 2weeks only 1/7 patient (14.2%) was hypocalcemic. Comparing the two groups, we highlighted that the utilization of NIR-AF was related to a significant decrease of median serum (p = 0.026) and ionized calcium levels (p = 0.017) 2weeks after surgery. Using this new technology, in no case did definitive histological examination reveal the presence of PGs in the surgical specimen, reaching an accuracy of 100%. In our cohort of patients who underwent total (pharyngo)laryngectomy with hemi- or total thyroidectomy, the use of near-infrared autofluorescence improved medium term postoperative hypocalcemia rates. This new technology helps to achieve a better calcemic outcome compared to the standard naked eye approach, since it helps the surgeon to identify and preserve parathyroid glandular tissue with a lower incidence of post-operative hypocalcemia.

Highly Sensitive Imaging Spectrometer System Based on Areal Array to Linear Array Optical Fiber Probe for Biological Spectral Detection

Noninvasive bio-molecular spectral sensing method for scattered tissue can be utilized to accurately obtain and analyze bio-molecular information. Propagation of light in biological tissues will gradually present diffusive feature and results in severe attenuation of detection light intensity and deteriorating the signal-to-noise ratio of detection system. In our work, we built a three-channel imaging spectrometer system and designed a compatible special fiber bundle probe for diffusive spectral detection. The system can synchronously collect the spectral signals from 270 fibers in the fiber bundles then convert them into electrical signal. Aiming at the aberration in the system, we also designed a corresponding data processing method to effectively realize the wavelength calibration of spectral signals. Finally, the system was applied to the nondestructive detection of human tissues and mouse with the <inline-formula> <tex-math notation="LaTeX">$15 ~ \mu \text{W}$ </tex-math></inline-formula> white light and 4.05 mw 405 nm laser. For the above extremely weak excitation light source, our system can still obtain the high signal-to-noise ratio diffusive spectra with less than 1 s integration time. Experiments were conducted to obtain spectra of back-scattering and autofluorescence of biological tissue. Experimental results show that the system has certain advantages in biological tissue scattering spectroscopy detection and autofluorescence detection.

Autofluorescence detection and co-axial projection for intraoperative localization of parathyroid gland

BackgroundNear-infrared (NIR) autofluorescence detection is an effective method for identifying parathyroid glands (PGs) in thyroidectomy or parathyroidectomy. Fiber optical probes provide quantitative autofluorescence measurements for PG detection owing to its high sensitivity and high excitation light cut-off efficiency at a fixed detection distance. However, an optical fiber probe lacks the imaging capability and cannot map the autofluorescence distribution on top of normal tissue background. Therefore, there is a need for intraoperative mapping of PGs with high sensitivity and imaging resolution.MethodsWe have developed a fluorescence scanning and projection (FSP) system that combines a scanning probe and a co-axial projector for intraoperative localization and in situ display of PGs. Some of the key performance characteristics, including spatial resolution and sensitivity for detection, spatial resolution for imaging, dynamic time latency, and PG localization capability, are characterized and verified by benchtop experiments. Clinical utility of the system is simulated by a fluorescence-guided PG localization surgery on a tissue-simulating phantom and validated in an ex vivo experiment.ResultsThe system is able to detect indocyanine green (ICG) solution of 5 pM at a high signal-to-noise ratio (SNR). Additionally, it has a maximal projection error of 0.92 mm, an averaged projection error of 0.5 ± 0.23 mm, and an imaging resolution of 748 μm at a working distance ranging from 35 to 55 cm. The dynamic testing yields a short latency of 153 ± 54 ms, allowing for intraoperative scanning on target tissue during a surgical intervention. The simulated fluorescence-guided PG localization surgery has validated the system’s capability to locate PG phantom with operating room ambient light interference. The simulation experiment on the PG phantom yields a position detection bias of 0.36 ± 0.17 mm, and an area intersection over unit (IoU) of 76.6% ± 6.4%. Fluorescence intensity attenuates exponentially with the thickness of covered tissue over the PG phantom, indicating the need to remove surrounding tissue in order to reveal the weak autofluorescence signal from PGs. The ex vivo experiment demonstrates the technical feasibility of the FSP system for intraoperative PG localization with accuracy.ConclusionWe have developed a novel probe-based imaging and navigation system with high sensitivity for fluorescence detection, capability for fluorescence image reconstruction, multimodal image fusion and in situ PG display function. Our studies have demonstrated its clinical potential for intraoperative localization and in situ display of PGs in thyroidectomy or parathyroidectomy.

Autofluorescence Detection and Perfusion Assessment of Parathyroid Glands in Transoral Thyroid Excision

Autofluorescence Detection and Perfusion Assessment of Parathyroid Glands in Transoral Thyroid Excision

Auto-Fluorescence in Phytoliths—A Mechanistic Understanding Derived From Microscopic and Spectroscopic Analyses

The detection of auto-fluorescence in phytogenic, hydrated amorphous silica depositions (phytoliths) has been found to be a promising approach to verify if phytoliths were burnt or not, especially in archaeological contexts. However, it is unknown so far at what temperature and how auto-fluorescence is induced in phytoliths. We used fluorescence microscopy, scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX), and Fourier transform infrared spectroscopy to analyze auto-fluorescence in modern phytoliths extracted from plant samples or in intact leaves of winter wheat. Leaves and extracted phytoliths were heated at different temperatures up to 600°C. The aims of our experiments were i) to find out what temperature is needed to induce auto-fluorescence in phytoliths, ii) to detect temperature-dependent changes in the molecular structure of phytoliths related to auto-fluorescence, and iii) to derive a mechanistic understanding of auto-fluorescence in phytoliths. We found organic compounds associated with phytoliths to cause auto-fluorescence in phytoliths treated at temperatures below approx. 400°C. In phytoliths treated at higher temperatures, i.e., 450 and 600°C, phytolith auto-fluorescence was mainly caused by molecular changes of phytolith silica. Based on our results we propose that auto-fluorescence in phytoliths is caused by clusterization-triggered emissions, which are caused by overlapping electron clouds forming non-conventional chromophores. In phytoliths heated at temperatures above about 400°C dihydroxylation and the formation of siloxanes result in oxygen clusters that serve as non-conventional chromophores in fluorescence events. Furthermore, SEM-EDX analyses revealed that extractable phytoliths were dominated by lumen phytoliths (62%) compared to cell wall phytoliths (38%). Our findings might be not only relevant in archaeological phytolith-based examinations, but also for studies on the temperature-dependent release of silicon from phytoliths and the potential of long-term carbon sequestration in phytoliths.

Detection of near-infrared autofluorescence from adrenal neoplasms: An initial experience.

Fluorescence from adrenal tumors can be detected with near-infrared imaging after injection with indocyanine green. However, it is unknown if adrenal tumors exhibit autofluorescence. The aim of this study was to determine whether adrenal tumors emit near-infrared autofluorescence (NIRAF). This was a prospective study of patients who underwent minimally invasive adrenalectomy at a tertiary center. Intraoperative images were analyzed to detect NIRAF with a 750 nm camera. Descriptive and comparative statistical analyses were performed. Twenty-five adrenalectomies were examined. Only 11tumors (44%), that originated from the cortex exhibited autofluorescence. A contrast distinction between the tumor and retroperitoneum was observed in 23 patients, whereas a contrast distinction between the tumor and normal adrenocortical tissue was seen in 12 patients. The overall fluorescence intensity of adrenal tumors was found to be variable and ranging between 0.3 and 5.6 times that of the background tissue. Pheochromocytoma, malignancy and adrenal cyst did not demonstrate NIRAF. This is the first study to show that adrenocortical tissue can demonstrate NIRAF. The pattern of fluorescence was similar to that observed after indocyanine green injection in our historical experience. NIRAF has a potential to be used as an intraoperative optical adjunct during adrenalectomy.

An Efficient and Fast, Noninvasive, Auto-Fluorescence Detection Method for Early-Stage Oral Cancer

This article proposes an efficient and fast auto-fluorescence method for early-stage oral cancer detection. Using mechanical composition analysis and 3-D modeling, the simple automatic equipment prototype with noninvasive detection and real-time observation is constructed. Herpes simplex, sublingual gland cysts, and biological enzyme solutions [flavin adenine dinucleotide (FAD) and nicotinamide adenine dinucleotide (NADH)] at different concentrations are detected using a 560-nm filter with a bandwidth of 30 nm, and ultraviolet LED (UV-LED) light sources at 3 and 5 W with wavelengths of 375, 395, 405, 410, and 420 nm, respectively. Also, the applicability of the detection conditions for several regions of the oral cavity is demonstrated in detail. Experimental results show that the specificity of 0.95 by selecting UV-LED with specific wavelength and observing the characteristics of lesions. The proposed detection method will be helpful in screening oral cancer and auto-detection of precancerous lesions.

Development of a non-invasive, dual-sensor handheld imager for intraoperative preservation of parathyroid glands.

Intraoperative localization and preservation of parathyroid glands (PTGs) are challenging during thyroid surgery. Using a technique of combined near-infrared PTG autofluorescence detection and dye-free imaging angiography, this study developed a portable device for localization of PTGs and assessment of viability by confirming tissue perfusion. The imager's performance was evaluated through a pilot clinical study (N=10).