This PDF file contains the front matter associated with SPIE Proceedings Volume 11073, including the Title Page, Copyright information, Table of Contents, Author and Conference Committee lists.

Alzheimer’s disease (AD) is the most common form of dementia, which is one of the main death leading causes with around 46 million people affected worldwide. Alzheimer’s disease is characterized by the accumulation of extracellular deposits of proteins in the brain, known as amyloid-beta (Aβ) plaques. Currently, in-vivo detection of Aβ pathology is solely possible by two invasive techniques: the analysis of cerebral fluid or PET imaging. Raman spectroscopy may be an alternative way of in-vivo diagnosis of Aβ deposits as it is sensitive to concentrations of biomolecules. It is an established and common non-destructive technique, which in addition allows for minimal sample preparation. Recent publications on transgenic mouse and human AD brain tissue suggest that Raman spectroscopy is an adequate technique to identify and localize Aβ plaques1,2. However, publications on human tissue lack the proof of plaque existence at the same location, imaged with Raman spectroscopy. The present study is designed to confirm ultimately a match between Raman spectra and possible amyloid-beta plaque locations. This is achieved by superimposing the autofluorescence image, the Raman imaging map and the stained fluorescence image of the same tissue section. Additionally, obtained data will be compared to previous studies of post mortem human AD brain tissue that was formalin fixed and paraffin embedded.

Wound healing is a biological response in order to recover the tissue stability after injury. The impaired healing by third-degree, when the damage achieves the major part of dermis, is defined in four sequential and overlapping phases: Inflammation, transition, proliferative and maturative¹. The role of biochemical cascade associated in each phase are still not fully understood, thus systematic evaluations tests are crucial. In fact, the gold standard to interrogate the molecular signature of wound healing is concern on immunohistochemical analysis. This approach tends to be laborious, time-consuming and require multiple assays². Since Fourier transform infrared spectroscopy (FTIR) has been demonstrated in other studies to provide molecular change report upon biological samples, the present study aims to estimate the feasibility of FTIR to discriminate healthy and burned skin throughout wound stages.

The most common type of bladder cancer is urothelial carcinoma (UC), whose treatment depends from both tumour extension (stage) and aggressiveness (grade). The gold standard for detecting UC is white-light cystoscopy, followed by tissue biopsy and pathological examination for determining tumour stage and grade. However, such process is invasive, time-consuming and prone to sampling errors. In this framework, optical spectroscopy techniques provide fast, label-free and non-invasive alternatives to standard histopathology. Thus, we combined auto-fluorescence, diffuse reflectance and Raman spectroscopy in a compact and transportable setup based on an optical fibre-probe. The latter was coupled to three laser diodes (emitting at 378 nm, 445 nm and 785 nm) and to a halogen lamp for exciting and collecting autofluorescence, Raman and reflectance spectra, respectively. This experimental setup was used for studying fresh biopsies of urothelial tumour (103 samples) and healthy bladder (34 samples) collected from 63 patients undergoing Transurethral Resection of Bladder Tumours (TURBT). All spectral recordings were done within 30 minutes from surgical resection, and optical inspection required less than 2 minutes for each sample. The recorded data were analysed using Principal Component Analysis (PCA) for obtaining an automated classification of the examined samples based on the intrinsic spectral information provided by all three techniques. We found that multimodal spectroscopy provides high-sensitivity, high-specificity discriminating capability for UC detection, grading and staging. The presented strategy generates results similar to gold standard histology, but in a fast and label-free way, offering the potential for endoscopic in vivo applications.

Raman spectroscopy has been applied to investigate the suitability of the drop coating deposition technique to study plasma samples from healthy donors and a patient with underlying cardiac condition. When blood plasma is deposited on a solid substrate, a droplet with coffee-ring is formed, and the plasma proteins will distribute inhomogeneously depending on the chemical and physical properties of the proteins. Changes in the fingerprint region of the Raman spectra were observed from the outer-ring and central zone of the droplet through a systematic investigation. For complete characterization of the sample, optimum measurement scheme has been proposed. To obtain clinically relevant information of the effects of immunoadsorption (IA) treatment of dilated cardiomyopathy (DCM) patient’s, Raman spectral information from outer-ring as well as from the central zone is required.

Recent discoveries suggest that ovarian cancer has its origins in the oviducts (Fallopian tubes) and may exist as intraepithelial carcinoma for up to 6 years. One route of access to the oviducts and ovaries is through the wall of the vagina. We have developed an approximately 3.8 mm diameter rigid salpingoscope for surveillance of high-risk women and early detection of ovarian cancer. The salpingoscope contains multiple advanced imaging modalities, as well as a channel for instillation of saline or dyes, and another channel for introduction of biopsy forceps. The single optical channel combines the modalities of multispectral fluorescence and reflectance wide-field imaging, multiphoton microscopy (MPM), and optical coherence tomography (OCT). Multiple modalities through a single channel are achieved by a novel lens system with dichroic coatings which create separate optical paths for visible wavelengths (low numerical aperture (NA) imaging) and near-infrared wavelengths (high NA imaging). A quartered piezoelectric tube actuator scans a dual-clad fiber with added mass to facilitate both relatively slow (OCT) and fast (wide field and MPM) scanning. Visible wavelength laser diodes are the source for wide field reflectance and fluorescence imaging, with remitted light collected through 12 high NA multimode fibers. A novel femtosecond laser with near-infrared output provides the source for OCT and MPM, with remitted light collected through the core and inner cladding of the dual-clad fiber, respectively. Detectors include high sensitivity photodiodes for wide field, a linear array with spectrometer for OCT, and photomultiplier tubes to collect twoand three-photon signals for MPM imaging.

We demonstrate that a RGB camera and a continuous wave white light illumination is a suitable approach to intraoperatively localize in real time the sensory and motor areas of the patient brain. The analysis of the reflectance spectra of the acquired light and Monte Carlo simulations allow us to measure the concentration changes of oxygenated and deoxygenated hemoglobin during the video acquisition. These measures are compared to the expected hemodynamic response to precisely localize the functional areas of the patient brain.

Mueller polarimetric imaging appeared to be very promising to detect the modifications in the microstructure of the uterine cervix due to the development of a precancerous lesion, thus providing very useful information for diagnostics to which practitioner cannot to access with classic color imaging. The first multispectral Mueller Polarimetric Colposcope (MPC) for the in vivo analysis of the uterine cervix will be presented. It has been obtained by miniaturizing a Mueller polarimetric imaging system and “grafting” it on a conventional colposcope, which is a low magnification binocular system, currently used in medical practice to examine the uterine cervix for detection of precancerous lesions. The multispectral MPC enables to obtain reliable Mueller polarimetric images in less than 2 seconds with a spatial resolution of 100 μm simultaneously at 450, 550 and 650 nm. Currently, it is being tested in vivo in the University Hospital of Kremlin Bicêtre in France. In order to evaluate the performance of the technique, polarimetric images need to be compared with histological analyses of biopsies. The procedure developed in collaboration with medical doctors to obtain an accurate correlation between polarimetric images and biopsies will be described.

The effective and non-invasive diagnosis of skin cancer is a hot topic in biophotonics since the current gold standard, biopsy followed by histological examination, is a slow and costly procedure for the healthcare system. Therefore, authors have put their efforts in characterizing skin cancer quantitatively through optical and photonic techniques such as 3D topography and multispectral imaging. Skin relief is an important biophysical feature that can be difficult to appreciate by touch, but can be precisely characterized with 3D imaging techniques, such as fringe projection. Color and spectral features given by skin chromophores, which are routinely analyzed by the naked eye and through dermoscopy, can also be quantified by means of multispectral imaging systems. In this study, the outcomes of these two imaging modalities were combined in a machine learning process to enhance classification of melanomas and nevi obtained from the two systems when operating isolately. The results suggest that the combination of 3D and multispectral data is relevant for the medical diagnosis of skin cancer.

We have developed a low-cost, wearable, CMOS-based device for the long-term measurement of skin physiological parameters in contact with tissue from spatially resolved diffuse reflectance measurements. The device has been tested for the assessment of the tissue oxygenation in vivo.

The purpose of this study was to determine potential of remote photoplethysmography for skin perfusion monitoring, using 540 nm narrowband and 530 nm broadband illuminations. The alterations of cutaneous circulation were produced by topical skin heating protocol. The setup comprises of 530 nm LED light source and two identical cameras operated simultaneously: one equipped with narrowband optical filter (CWL=540nm), and another without filter. Results demonstrate the typical heating test response curve- comprising first peak, nadir and plato phase, which were significantly different in narrowband and broadband illumination. It was concluded that selection of optimal light source parameters is crucially important for registering of physiological responses using rPPG, and therefore require more extensive studies.

Diabetes mellitus 1 requires tight control of the blood glucose levels to avoid harmful effects of either too high (hyperglycemia) or too low (hypoglycemia) blood sugar. Due to the availability of low-cost components, fiber- coupled near infrared (NIR) absorption spectroscopy could be a feasible measurement method. From the molar absorptivity of glucose, it is shown that to achieve high accuracy using near infrared spectroscopy for glucose sensing, relative noise levels should not exceed 0:003 %. Two supercontinuum (SC) sources and one broadband lamp were investigated with a low-cost portable spectrometer. The SNR of the two SC sources was limited by amplitude fluctuations and could be improved by averaging. The SNR of the broadband source was found to be largely limited by the detector noise due to the weak intensity. 16 aqueous glucose samples ranging from 0 to 500mm were measured with the broadband source and an SC laser. A partial least squares regression (PLSR) model was built for both measurement sets, yielding root mean square errors of 49 and 54mm, illustrating how the limit of detection is restrained by the high relative intensity noise. A reference arm setup was built and could account for much of the variability of the SC source. A glucose measurement series using this setup and five samples (100 to 500mm) yielded a root mean square error of 10:6mm. The results indicate that an SC source can be feasible for absorption spectroscopy in a reference arm setup.

Mueller polarimetry has been shown to effectively detect multiple pathologies on a striking variety of biological tissues. The ongoing challenge is to implement Mueller polarimetry into the clinical practice in-vivo. This technique is suitable for this purpose since it provides wide field images (up to 20 cm²) well adapted to the exploration of entire organs while revealing information on their microstructure. In addition, it is non-invasive, label-free and non-destructive. One instrument of great interest for biomedical diagnostics in vivo is the conventional rigid endoscope, also called laparoscope. This instrument is used to explore the inner cavities of the human body and is a standard in many minimally invasive surgery applications. However, it is implemented by using conventional white light intensity imaging which does not provide enough contrast to identify, for example, tumor margins during surgical resection. Mueller polarimetric imaging could provide useful contrast which can considerably improve the definition of these margins. However, to adapt a conventional laparoscope to Mueller polarimetric imaging is an instrumental challenge due to its complex polarimetric response. In this work, we provide a detailed characterization of the polarimetric properties of a conventional laparoscope. It is shown that a conventional laparoscope is characterized at the same time by birefringence and strong spectral depolarization that can be reduced by reducing the spectral bandwidth. The origin of these polarimetric effects have been investigated and modeled. Our work provides useful knowledge about implementing rigid endoscopes in polarimetric applications.

Depth sensitive optical spectroscopy detects optical spectra from different layers in layered samples, revealing crucial information about the samples, for example, and the progress of epithelial cancer. In depth sensitive fluorescence measurements, multiple light scattering in tissues significantly degrades the depth sensitivity to a subsurface target layer. To address this issue, feedback based wavefront shaping led by guide stars can be used to refocus light to increase the depth sensitivity to a target layer. However, the low target to background ratio caused by multiple scattering in tissue leads to weak fluorescence measurement from the target layer inside. In this study, we demonstrate that by using feedback based wavefront shaping, we can increase the signal contribution from the target and suppress that from the background region in tissue-like scattering phantoms. After wavefront optimization, the signal from the target can increase by quite a few times. Feedback based wavefront shaping can be very useful in depth sensitive fluorescence spectroscopy for the characterization of layered structures such as epithelial tissues.

We propose an ultrasonic-assisted point-one-shot mid-infrared Fourier spectroscopy device involving an ultrasonic liquidcell and point-one-shot Fourier spectroscopy (diameter: 6 mm, thickness: 5 mm) for ear clip type non-invasive blood glucose sensors, at a low cost (approximately 1,000 EUR). As the prevalence of diabetes increases over time, methods for non-invasive monitoring of blood glucose concentration in daily life are increasingly important for diabetes control and prevention. However, there are currently no sensors for non-invasively detecting biological components in daily environments. In the current study, we propose a point-one-shot Fourier spectroscopy method comprising one objective lens and a camera. The objective lens is a spherical lens at the front side and a dual-axis wedge prism inclined along the horizontal and vertical axes. An objective beam is collimated by the objective lens, with a difference in optical path length caused by the wedge prism. This device can be used to obtain two-dimensional spatial fringe patterns. Conventional oneshot Fourier spectroscopy produces one-dimensional fringe patterns in the horizontal direction of the array device. Thus, the maximum optical path length is limited by the number of pixels in only the horizontal line of the array device. However, our proposed point-one-shot Fourier spectroscopy device can produce an interferogram with longer maximum optical path lengths compared with conventional devices because horizontal lines at difference rows are connected by the same phase pixel. Thus, spectroscopic imaging devices can be produced at a low cost because low-resolution cameras (e.g., 80 × 80 pixels) can be used for spectroscopy.

Biodynamic imaging of chemotherapy response in ex vivo patient biopsies measures changes of intracellular dynamics in response to applied therapeutics. The technique is based on near-IR low-coherence digital holography of Dopplerbroadened light scattering from intracellular dynamics. Three clinical trials of this diagnostic biophotonic technology are nearing completion in esophageal cancer, epithelial ovarian cancer and breast cancer.

The use of iSPIM and optical-clearing enables 3D high-content histological imaging of large tissues with subcellular resolution and almost 2 mm imaging depth, providing 3D structural information for generating tissue models or for validating low-resolution imaging modalities.

Cryolipolysis has become a popular non-invasive method of reducing excess fat by cooling. However, the results vary as metabolism, gender and diet may affect the freezing point of human subcutaneous fat. To increase the success for all patients, it is essential to better understand the process of cryolipolysis in vivo. Therefore, we have developed a side-facing needle probe with an outer diameter of 390 μm achieving a lateral resolution of 10 μm at a working distance of 1.5 mm. To obtain a spatially resolved visualization of the immediate processes involve in cryolipolysis, cross-sectional images was obtained by moving the needle probe back and forth in a transparent catheter. At the tip, the transparent catheter was equipped with a lancet for smoothly penetrating through the skin. By a rigorous design including optical wave simulation and by a careful combination of different materials astigmatic aberrations were avoided. Ex vivo measurements on subcutaneous porcine fat were performed to confirm, that imaging with the needle probe is a suitable method for investigating phase changes.

Infra-red (IR) spectroscopic imaging of live cells is greatly affected by the presence of water, which is a strong absorber of IR radiation. In order to overcome this, a variety of methods have been developed using complex microfluidic devices to reduce the liquid sample path length. However, these devices are often custom made needing both specialised equipment and detailed fabrication steps. Here we show the novel utilisation of a liquid-air interface configuration and a negative contrast imaging device (NCI) reflectance imaging system for the collection of spectral data from live cells within an in vitro environment. Spectral differences were observed between two different cell densities, both in the presence and absence of cell culture media. Additionally, differences were observed between control and test cultures exposed to dimethyl sulfoxide (DMSO) to induce cell apoptosis. The NCI system acquired data in the 2.5 – 3.5 μm spectral region, at a spectral sampling interval of 10 nm. This method will allow further investigation of spectral biomarkers within cell cultures to augment understanding of specific cell contributions to wound healing in vivo.

To improve the spatial resolution in near-infrared-ray computed tomography (NIR-CT), a first-generation scanner in the first-living-body window was constructed. The NIR photons are produced from an 850 nm laser module, and penetrating photons from an object are detected using a photodiode (PD). To improve the spatial resolution, we used a 1.0-mm-diam graphite pinhole and a 1.0-mm-diam 5.0-mm-length graphite collimator. To detect the penetrating photons, the pinhole is set behind the object, and the collimator is attached to the PD to improve the spatial resolution. The NIR-CT is accomplished by repeated translations and rotations of the object. The translation is performed by the object moving between the laser and the PD modules. The translation and rotation steps were 0.25 mm and 1.0°, respectively, and the spatial resolutions were determined as 1.0×1.0 mm². The scanning time and the total rotation angle for CT were 9.8 min and 180°, respectively.

The absorption coefficient μa and scattering coefficient μ´s of different tissue types obtained during parotidectomy are determined in the wavelength range of 250 nm to 800 nm. These values are obtained by high precision integrating sphere measurements in combination with an optimized inverse Monte Carlo simulation (iMCS). To conserve the optical behavior of living tissues, the optical spectroscopy measurements are performed directly after tissue removal. This study includes fresh samples of the ear, nose and throat (ENT) region, as muscle tissue, nervous tissue, white adipose tissue, stromal tissue and parotid gland of five patients. The measured behavior of adipose corresponds well to the literature, which sustains the applied method. It is shown, that muscle is well supplied with blood as it features the same characteristic peaks at 430 nm and 555 nm in the absorption curve. The parameter μ´s decreases for all tissues type above 570 nm. The accuracy is adequate for the purposes of providing μa and μ´s of different human tissue types as muscle, fat or gland tissue, which are embedded in large complex structures such as in the ENT area. It is therefore possible for the first time to present reasonable results for the optical behavior of human soft tissue located in the ENT area and in the near-UV, visual and near-IR areas.

We construct stochastically inhomogeneous epithelial cell models via simulation of Gaussian random fields; the extent and correlation length of subnuclear refractive index fluctuations are based on values quantified from high-resolution images of cervical tissue. We then employ the finite-difference time-domain method to simulate azimuth-resolved light scattering patterns of the constructed models. We process these two-dimensional patterns and calculate a series of Haralick features with the ultimate goal of identifying signatures that directly point to changes in subnuclear refractive index profile. Our results show that azimuthal contrast calculated over specific angular ranges is highly sensitive to the extent and correlation length of refractive index fluctuations. This metric is insensitive to changes in the overall size and mean refractive index of the constructed models, thereby allowing for selective tracking of changes in subnuclear refractive index variations.

The problem of complete resection of human brain glioma during neurosurgery is still one of the most challenging, since the existed diagnostic methods are plagued with limited sensitivity and specificity; they remain laborious, time-consuming and/or rather expensive. The present work includes the ex vivo study of malignant brain gliomas featuring different grades (according to the World Health Organization) by means of two methods, i.e. optical coherence tomography (OCT) and terahertz pulsed spectroscopy (TPS). Both OCT and TPS studies were done just after the tissue resection and included gelatin embedding of the samples for conservation of water content. The further histological examination using hematoxylin and eosin (H&E) stained microscopy approved the diagnosis. The results demonstrate the potential of TPS to differentiate intact and malignant tissues and the potential of OCT to differentiate low- and high-grade gliomas as well as intact tissue and low-grade gliomas. Thus, combination of these modalities seems to be rather prospective for the further development of the advanced intraoperative diagnostic tools.

Fourier Transform Infrared (FTIR) spectroscopy is a label-free analytical technique used to evaluate the chemical profile of a sample based on its molecular vibrations. The potential dermatological applications of FTIR spectroscopy has been well demonstrated over the past decades through many proof-of-concept studies evaluating cancerous and non-cancerous cutaneous diseases. Considering that the correctly identification of skin components plays an important role in the study of cutaneous diseases, the present study aims to evaluate the spectrochemical signatures of dermis and epidermis based on the pixels of a FTIR hyperspectral image collected from healthy skin.

Gliomas are diffuse brain tumors still hardly curable due to the difficulties to identify their margins. 5-ALA induced PpIX fluorescence measurements have enabled to gain in sensitivity for discriminating margin from healthy tissue but they remain limited. In this study, we assume that two states of PpIX contribute to total fluorescence. We show that fluorescence in low density margins of high grade gliomas or in low grade gliomas comes mainly from PpIX peak centered at 620 nm. These results could help to improve fluorescence-guided resection of gliomas by discriminating healthy tissues from tumor margins.

Changes in the structure of the nasal mucosa can be a morphological biomarker and therefore helpful for diagnosis and follow-up of various pulmonary diseases such as asthma, cystic fibrosis and primary ciliary dyskinesia. In order to verify that microscopic optical coherence tomography (mOCT) is a valuable instrument for the investigation of those changes, an endoscopic OCT system with microscopic resolution (emOCT) was developed and built for clinical testing. The endoscope is based on a graded-index (GRIN) lens optic and provides a calculated lateral resolution of 0.7 μm and an axial resolution of 1.25 μm. The imaging depth was up to 500 μm in tissue; axially, a lateral range of approximate 250 μm could be covered. B-scans were acquired at 80 Hz with 512 pixels in lateral and 1024 pixels in depth-direction. The diameter of the endoscope decreases over a length of 8 cm from 8 mm at the beginning to 1.4 mm at the end and is small enough to observe the mucous membrane in the human nasal concha media and inferior down to the nasopharynx. The emOCT workstation was designed to meet German electrical, optical and biological safety standards. The applicability of the endoscope could be demonstrated in vivo. Mucus transport, glands, blood and lymphatic vessels could be visualized.

Novel imaging methods permitting real-time, wide-field and quantitative optical mapping of biological tissue properties offer an unprecedented range of potential new applications for clinical use such as guided surgery or patient monitoring. However, significant technical challenges have so far prevented such tools from performing in real-time (for both acquisition and processing) and therefore from being deployed in clinical practice. To overcome these limitations, recent research introduced methods based on Spatial Frequency Domain Imaging (SFDI) that allow real-time (within milliseconds) wide-field imaging of optical properties. In this study we present a novel implementation of general purpose graphic processing unit (GPGPU) direct programming in C CUDA (Compute Unified Device Architecture) for real-time, wide-field and quantitative multispectral imaging using our recently-developed spatio-temporal modulation of light imaging method. Using this new method, we are able to quantitatively obtain optical properties images (1 megapixel) at 2 wavelengths (665 nm and 860 nm) in only 1.52 ms with at most 1% error in comparison with standard Matlab processing.

In order to fully exploit the diagnostic potential of optical coherence tomography (OCT) in contemporary restorative dentistry, an intraorally applicable OCT probe has been constructed. The probe was connected to a commercially available OCT system. The handling of the probe and the quality of the OCT images were optimized and evaluated on human extracted teeth fixed in a patient-equivalent simulation. In addition, the probe was applied intraorally to volunteers. With the intraoral OCT probe hard tooth substances, carious lesions in enamel and dentin and composite restorations could be imaged. In vivo, the probe allowed OCT imaging of all tooth surfaces except the vestibular surfaces of third molars and proximal surface areas of molars within a "blind spot" at a distance of 2.5 mm from the tooth surface. Superficial tissue structures of the marginal gingiva could also be imaged. The intraoral OCT probe is a promising tool for non-invasive imaging and monitoring of healthy and diseased hard tooth substances and tooth-colored restorations. It can be a valuable addition to established methods for caries diagnosis and restoration evaluation.

Slide-free imaging of hematoxylin-eosin-stained whole mount tissues is demonstrated using multi-modal third harmonic generation and three photon fluorescence microscopy. As a result, the demonstrated microscopy shows promise for rapid margin assessment during surgery without compromising the contrast and features of conventional H&E histology.

Eye fundus photography routinely used in clinical practice is restricted to color imaging of the retina. In the last years, hyperspectral imaging has shown to be a powerful tool for the spectral analysis of biological tissue. In this study, we present a fully custom-made fast hyperspectral fundus camera based on light emitting diodes (LED) with 15 different wavelengths of emission and with extended spectral sensitivity towards the near infrared (NIR) (from 400 nm to 1300 nm), which allows imaging deeper retinal layers, including the choroid, than current clinical devices. These new features will be very useful for a better understanding of ocular diseases as well as aiding in their diagnosis.

Raman micro-spectroscopy was used for an in vitro investigation aimed to elucidate the effects of X-rays and polyphenols derived from autochthonous sweet cherries from Campania (Italy) on specific sub-cellular regions of single SH-SY5Y human neuroblastoma cells. Nucleus and cytoplasm regions of single cells were investigated after the exposure to different doses of X-rays (0, 2, 4 Gy). Cells were fixed immediately after irradiation and/or after having been exposed to the cherry polyphenol extracts. Two different concentrations of polyphenol extracts (25 μg/mL and 500 μg/mL) with an exposure time of 48 h to polyphenols were considered. A deconvolution procedure using Lorentzian curves along with the evaluation of ratios between the intensity of selected peaks were used for analyzing the collected spectra in order to highlight the changes due to the different treatments. Biochemical changes occurring in nucleus and cytoplasm regions of single cells as a consequence X-ray irradiation were observed. In particular, the analysis of Raman spectra allowed us to detect modifications in the contribute from proteins, nucleic acids, lipids, and carbohydrates of cells, induced at different extent on the two cell regions. In fact, in the absence of polyphenols, the most relevant effects were observed in the cell nucleus region where modifications in the cell cycle were detected with an increase of DNA/RNA contribution, protein rearrangement and changes in lipids. The presence of the extracts induced changes in the observed variations. Our approach was also able to show the radiomodulating effects induced by the presence of different doses of polyphenols and different exposure times to these substances.

The coupling of Lateral Flow Assays (LFA) to Surface Enhanced Raman Scattering (SERS) readout is promising to obtain field biosensors with exquisite sensitivity. For Point of Care (POC) applications, however, the operation of such a SERSLFA sensor needs to be automated. We developed an acquisition protocol together with a procedure for processing the Raman spectra to address this point. We describe this method and present some results obtained on Ovalbumin as a model target.

Utilization of surface-enhanced Raman spectroscopy as a measurement technique is of particular interest in biodetection due to its superb chemical specificity and high sensitivity. The use of SERS substrates further improve this method by massive enhancement of the molecule Raman spectrum, permitting very low levels of detection. Therefore it is important to seek for new ways to develop reliable substrates, which are quickly and easily manufactured at a low cost. This paper describes the development of a simple and cost-effective substrate for the SERS detection. The substrate is synthesized from a silver ink on the glass, and its utilization for biodetection is shown. The hydrophobicity of the substrate permits the pre-concentration benefit of the drop-coating deposition, by the formation of the coffee-ring. This allows to achieve lower limits of detection, by effectively measuring areas with higher concentration of measured molecules than the initial sample. However, the different properties of the medium, such as the influence of protein types and amounts, may influence the ring formation mechanics, thus effectively changing the pre-concentration of the target analyte.

Extracellular vesicles (EVs) are nanoparticles secreted from cells into bodily fluids. EVs are potential biomarkers for diseases such as thrombosis or cancer. However, the small size and low refractive index of EVs complicates their detection. A flow cytometer is suited for EV characterisation, but typically lacks scatter sensitivity on one or both scatter detectors for derivation of both particle size and refractive index. Here, we aim to improve the FACSCanto (Becton Dickinson) forward scatter detector for the detection of 100 nm EVs, which requires an improvement in SNR of 10⁷-fold based on Mie theory. This was achieved through replacement of the 20 mW laser by an 200 mW laser, replacement of the photodiode detector with a photomultiplier tube and a confocalized optical geometry. Using a prototype optical setup, we obtained an improvement in SNR which was 1,11·10⁴ – fold better than the standard design. However, the optics was suboptimal and far from diffraction-limited. Zemax simulations led to a nearly diffraction limited optical design which is expected to yield another 200-fold improvement. Taken together these changes will improve the SNR 2.2·10⁶-fold and thus improve the detection limit of the FACSCanto to 130 nm EVs.

We present three optical multi-channels spectrometers for the interrogation of label-free biosensors based on different kinds of transducers : resonant nanopillars (RNP), microring resonators (MRR), localized and propagative surface plasmon resonance (LSPR and SPR). Light is collected from the multi-channel biosensors (up to 12-channels) with optical fibers and is remapped to a packed straight line forming the input slit of the spectrometers. The combination of high resolution CMOS sensors and embedded signal processing makes it possible to extract the resonant wavelengths of the transducers with a precision in the range of 1-20 pm depending on the type of transducer. The performance of the three transducer / spectrometer systems has been evaluated in the framework of EU and regional projects for the monitoring of chemical pollutants found in oceanic waters (FP7 - EnviGuard), crop health monitoring (Interreg France-Wallonie-Vlaanderen - SmartBioControl/BioSens) and bioreactor monitoring (EutoTransBio - APTACHIP).

Rapid identification of bacterial infection is very important and in many cases can save human life. Many pathogens can cause infections. While these infections share identical symptoms, the immune system responds differently to these pathogens. The current microbiology lab methods used to diagnose the infection type are time consuming (2-4 days). Thus, physicians may be tempted to start unnecessary antibiotic treatment, based on their wrong diagnosis (based on experience) of the infection. Uncontrolled use of antibiotics is the main driving force for the development of multi drug resistant bacteria which is considered a global health problem. We hypothesize that the different responses of the immune system to the infecting pathogens, cause some minute biochemical changes in the blood componentsthat can be detected by infrared spectroscopy which is known as a fast, accurate, sensitive and low cost method. In this study, we used infrared microscopy to measure the vibrational spectra of white blood cells (WBC) samples of 105 infected patients (69 bacterial and 36 with viral infection) and 90 controls (non-infected patients). The obtained spectra were analyzed using machine learning algorithms to identify the infection type as bacterial or viral in a time span of less than one hour after blood sample collection. Our study results showed that it is possible to determine the infection type with high success rates of 93% sensitivity and 85% specificity, based solely on WBC obtained from simple peripheral blood samples.

Diagnoses performed on the basis of histopathological evaluation depend on the premise that information derived from a small number of samples is valid for the entire tissue volume. By insufficiently sampling a biopsy volume the ability of pathologists to draw meaningful inferences from the sample is impeded. This work attempts to apply an information theoretic approach to biopsy sampling rates informed by variation in tissue morphology identified by persistent homology. By quantifying the diagnostic information present in a sample may be possible to prevent under sampling by the clinician by creating a “Nyquist limit" for histopathological sampling given the frequency of morphologically distinct regions in a single biopsy.

A RGB camera and a continuous wave white light illumination is a suitable approach to intraoperatively localize the sensory and motor areas of the patient brain. The analysis of the reflectance spectra through the modified Beer-Lambert law enables us to measure the concentration changes of oxygenated and deoxygenated hemoglobin during the video acquisition. However these concentration changes depend on the wavelength dependent optical mean path length. A manual image segmentation and Monte-Carlo simulations allow us to precisely choose the mean path length in a pixel-wise manner.

Lack of corneal transparency is a major cause of blindness worldwide. However, means to assess corneal transparency are limited and in current clinical and eye-bank practice usually involve a subjective and qualitative observation of opacities, sometimes with comparison against an arbitrary grading scale, by means of slit-lamp biomicroscopy. To address this unmet need, we have developed a method for corneal transparency assessment based on a new optical data analysis-based approach. Our method allows the objective extraction of quantitative parameters (including the scattering mean-free path, l_s, a major indicator of scattering extent and thus of transparency of a medium) based on a physical model of corneal transparency and has been validated by laboratory experiments, using high-resolution, ex-vivo “fullfield” optical coherence tomography (FF-OCT). Here, we apply our algorithm to depth-resolved spectral domain OCT (SD-OCT) images of in-vivo corneas and demonstrate the feasibility of our approach by means of four representative clinical cases. Specifically, we illustrate its potential in discriminating between the four clinical cases and, if applicable, deriving the scattering mean-free path as a quantitative measure of corneal transparency from objective analysis of stromal light backscattering (attenuation of the coherent mean) with SD-OCT. This measure may be related to, or expressed as, Strehl ratio reduction and thus retinal PSF broadening. As such, our approach not only has the potential to supply the demand for an objective means to quantify corneal transparency in the clinical setting, but also to create an association with visual function.

In this work we demonstrate optical coherence tomography (OCT) to support peripheral nerve surgery which provides superior resolution than intraoperative sonography. For that purpose, a handheld probe covered with a sterile foil was utilized. In total 34 patients were measured with the OCT device during surgery. In this study eight different peripheral nerves have been accessed at various positions of the human body. It could be observed that near-surface nerves provided the best contrast. In the acquired images it was possible to identify single fascicles within the volumetric images of the peripheral nerves. However, due to the use of a sterile foil, the sensitivity was decreased compared to ex vivo results. In order to highlight different areas within a nerve, e.g. the perineurium, texture analysis was performed. Thus, chronic nerve compression with an enhanced amount of connective tissue can be precisely located. We are confident that in the future this methodology can provide high resolution images of a peripheral nerve’s microstructure in real time, which leads to multiple possible applications, e.g. the revealing of scar tissue or the direct optical biopsy without the need of a pathological analysis.

Terahertz time-domain spectroscopy (THz-TDS) has been applied to medical applications as THz waves are sensitive to biomolecules. In this paper, terahertz time-domain attenuated total reflection spectroscopy (THz-ATR) was used to identify human colon cancer cell line. The refractive indices of cancerous and normal cell lines with six different concentrations were analyzed in the frequency domain from 0.1-1.2THz. t-Distributed Stochastic Neighbor Embedding (t-SNE) and Principal Components Analysis (PCA) methods were adopted to extract the key features from the THz spectrum. Experimental results showed that the features extracted by t-SNE had better recognition accuracy owing to enhanced clustering efficacy. This work may be helpful for detecting human colon cancer cells by using terahertz techniques.

Cancer prognosis and treatment efficacy are assessed by evaluating the hallmarks of a tumor which are volume change of the tumor and the vascular network reformation around a tumor. Non-invasive quantitative assessment of those indications, in-vivo, is still a challenge for traditional imaging modalities, owing to a large interrogation area and deep-seated molecular (fluorescence) signal in highly scattering, anatomically complex skin tissue. Currently available techniques either utilize surgically implanted imaging windows or conduct terminal experiments for each time point. The former is prone to inflammation at the implantation site thus interfering with the tumor microenvironment. The latter one is prone to sample variability thus results in a pseudo-longitudinal outcome for tumor development. Here, we combine Intravital Fluorescence Tomography (IFT) and Spectral Domain Optical Coherence Tomography (SD-OCT) for tumor imaging with a Non-invasive Intravital Imaging Window (NIIW) for tissue stabilization. This platform enabled us to follow tumor development non-invasively covering tumor initiation, development and regression on the same animal over months-long period. IFT-OCT multimodal imaging not only reveals tumor volume change but also skin anatomical features, and it is capable of revealing neo-vascularization around the tumor site. This platform thus serves as a useful non-invasive tool to explore future research questions pertaining to cancer biology in common fluorescence-based mouse models, such as tumor progression or treatment efficacy. In addition, our multi-modal platform alleviates the burden put on animals while imaging and reduce the experimental cost significantly.

Raman spectroscopy has demonstrated its great potential in skin wound assessment. Given that biochemical changes in skin wound healing is a layer dependent process, depth sensitive Raman spectroscopy could enhance the power of Raman spectroscopy in this application. Considering the critical importance of rodent studies in the field of skin wound assessment, it is necessary to develop and validate a system that can perform depth sensitive measurements in rat skin with a proper target depth range. In this manuscript, we report the design, optimization and evaluation of a new snapshot depth-sensitive Raman instrument for rat skin measurements. The optical design and optimization process are presented first. The depth sensitive measurement performance is characterized on ex vivo rat skin samples with wounds. Raman signal emitted by the ex vivo rat skin from different target depths were simultaneously acquired. The feasibility of using the measured Raman spectra to differentiate between the wound edge and healthy skin was validated using PLS-LDA with leave-one-out. The accuracy of the classification improves monotonically as more data from new depths are used, which implies that each depth offers additional information useful for classification. This instrument demonstrates the ability to perform snapshot depth sensitive Raman measurements from rat skin, which paves the way towards in vivo preclinical studies of rat skin wounds.

While passive thermal imaging of temperature difference between tumor and neighboring tissue provides limited contrast, active infrared thermal imaging with external heating or cooling may provide a unique contrast mechanism due to distinct thermal responses of tumor from neighboring tissue. We previously developed an active thermo-modulation imaging method with physiologically relevant parameters including the rate of temperature change and thermal relaxation time for tumor detection. Different from conventional passive thermal imaging, active thermo-modulation provides a contrast factor which is the average rate temperature change between tumor and neighboring tissue. With the tumors, the average rate of temperature change was higher than that of neighboring tissue with heating and cooling modulation. For endoscopic infrared thermal imaging, anti-reflection germanium lenses are tested as they have higher reflected indices and transmittance at mid-infrared spectrum. Combined with thermo-modulation, the newly developed infrared endoscopy can advance label-free non-invasive endoscopic screening.

Ovarian cancer is the deadliest gynecologic cancer, but can be addressed with early detection. We investigate optical coherence tomography for imaging ovarian cancer, finding that tissue changes can be detected through quantitative analysis.

The present study is devoted to the assessment of oral mucosa perfusion using remote photoplethysmography (rPPG) technique. The alterations of mucosal perfusion were evoked by regional infiltration anesthesia containing adrenaline. Simple rPPG setup comprising white LED light source, video camera and narrowband optical filter (CWL=540nm), are able to detect subtle microcirculation changes in gingiva. Results demonstrate substantial decrease of rPPG waveform amplitude and subsequently perfusion index in affected gingiva region, following administration of anesthetics. The present study emphasizes clinical advantages of remote photoplethysmography and perfusion index mapping as a simple and cost-effective technique for assessment of oral mucosa function.

Optical spectroscopy is a fast, label-free and non-invasive method for analysing tissue composition and, thus, has the potential for improving standard diagnostic capabilities. This is particularly relevant for brain surgery due to the lack of contrast between diseased tissues (e.g. malformations and tumours) and the surrounding brain. In this study, we used an optical fibre-probe system combining multiple spectroscopic techniques for analysing ex vivo human brain biopsies taken from both tumour and dysplastic tissues. Specifically, the probe – based on a fibre-bundle with optical fibres of various size and properties – allowed performing spectroscopic measurements based on fluorescence, Raman, and diffuse reflectance spectroscopy. Two visible laser diodes were used for fluorescence spectroscopy, a laser diode emitting in the NIR was used for Raman spectroscopy, and a fibre-coupled halogen lamp for diffuse reflectance. All spectral recordings were done within 30 minutes from surgical resection, and optical inspection required less than 2 minutes for each sample. The recorded data were analysed using Principal Component Analysis (PCA) for obtaining an automated classification of the examined samples based on the intrinsic spectral information provided by all three techniques. The presented method demonstrated high sensitivity and specificity in discriminating different tissue types in good agreement with histopathological examination. Furthermore, we found that the multimodal approach is crucial for improving diagnostic capabilities beyond what can be achieved from individual techniques.

Tissues-mimicking phantoms are widely used for performance evaluation of imaging systems. Disease specific design of the phantom is necessary for the correct assessment of a system’s parameters. Such phantoms are a key requirement for the continued development of various imaging techniques such as optical coherence tomography (OCT), which has been successfully applied for diagnosis of diseases in the esophagus and preliminary data show that it can be also highly perspective for diagnosis of colorectal cancer. However, in vivo validation of this novel optical approach is often difficult, since the disease model development in large animals, such as pigs, is a quite challenging task. The optimal colorectal cancer phantoms should have the following criteria: 1) realized geometry in three dimensions, 2) customizable material and optical properties, 3) mounting system allowing placement in various locations of the bench-top colon model (plastic or tissue) and removal using standard endoscopic tools, 4) visual appearance compatible with white light endoscopic imaging, and 5) long term stability. To match all these criteria, we propose tissue-mimicking phantoms prepared using 3D printing and PDMS/TiO₂ insertions for cancer-like regions that are covered with the layer of Dragon skin to color-match the mucosa appearance, as we believe these materials are the most promising for durable and accurate replication of tissue properties. The polyps are mounted in the colon using small neodymium magnet embedded in the base of the polyp. The developed polyps were evaluated using optical coherence tomography system.

Skin cancer is the most common type of malignant tumors in humans. Early diagnosis is the key to successful surgical treatment. In this work we present a non-invasive screening tool for early stage detection of skin cancer and also for the evaluation of post-operative scars.

This study explores endobronchial optical coherence tomography (OCT) imaging of lung transplant patients with chronic lung allograft dysfunction (CLAD). Optical coherence tomography (OCT), the optical analog of ultrasonography with superior resolution (10μm) but shallow (2mm) penetration, allows for the visualization of the early structural changes in the small airways, which is of interest in CLAD progression. Imaging was conducted with a catheter-based rotary OCT probe during routine bronchoscopy procedures, resulting in three-dimension pullbacks of three subsegmental airways per patient (n=9). A scoring rubric for visualized features of interest was used to quantify characteristics of the image set: loss of alveolar visualization, emphysema-like alveolar enlargement, alveolar hyperinflation, airway dilation, excessive mucous, excessive duct-like structures, and an unidentified structure. Four raters, blinded to clinical status, scored the set. Statistical analysis including Pearson correlation coefficients (R), Fleiss’ Kappa (κ) were used on this score set to assess preliminary potential of these features. 3/9 patients met the diagnostic criteria for both obstructive (BOS) and restrictive (RAS) phenotypes of CLAD and 6/9 for solely the obstructive phenotype. The airway dilation feature was found to be significantly associated (p<0.05) with the BOS+RAS diagnosis for three raters (R=0.72-0.94), with fairly consistent rater reliability (κinterrater = 0.25, κintrarater = 0.59). No OCT features were significantly correlated with infection status. Small airway dilation, as measured through catheterized OCT imaging, shows potential for use in detection of CLAD and distinguishing between CLAD phenotypes.

Optical coherence tomography (OCT) is a contactless and non-invasive imaging technique. Due to the high resolution of some 10 μm and the penetration depth of 1-2 mm in scattering tissue, OCT closes the gap between microscopy and sonography. Here, we present a GRIN-based endoscopic OCT (eOCT) system for middle ear diagnostics. EOCT combines the benefit of endoscopic imaging and the advantage of morphological and functional investigation of the tympanic membrane (TM). The eOCT system has a working distance of 10 mm, which results in a field-of-view of 10 mm. This allows a full three-dimensional visualization of the TM and surrounding tissue. In addition, the oscillation of the TM can be measured spatially resolved and in the frequency range between 500 Hz and 5000 Hz with 125 Hz resolution, which is realized by phase-resolved Doppler-OCT. First clinical results are demonstrated for one selected cases, a middle ear effusion.

Fourier-Transform Infrared micro-spectroscopy (μFT-IR) was used for an in vitro investigation targeted to examine the effects on SH-SY5Y human neuroblastoma cells of X-rays irradiation. μFT-IR thanks to its ability in analyzing cells at a molecular level can be particularly useful in investigating the biochemical changes induced in protein, nucleic acid, lipid, and carbohydrate content of cells after irradiation by graded X-ray doses (0, 2, 4, 6, 8 and 10 Gy). Cell samples were fixed immediately (t0-cells) or 24h after (t24-cells) irradiation. A deconvolution procedure using Lorentzian curves was used for analyzing the collected spectra in order to highlight the changes due to the different treatment. Significant differences were evidenced in spectra from unexposed and exposed cells. Peaks related to important cell components (as Amide and DNA) show significant shifts depending on radiation dose and also the ratios between the intensity of selected bands are affected by the interaction with ionizing radiation. These changes are less evident in t24h-cells, thus suggesting the occurrence of repairing processes of the X-ray induced damage. The results of the present analysis can be helpful in order to develop innovative approaches to monitor radiation cancer radiotherapy outcome so as to reduce the overall radiation dose and minimize damage to the surrounding healthy cells, both aspects being of great importance in the field of radiation therapy.

Glioblastoma (GBM) is the most common and aggressive malignant brain tumour in adults. Patient survival rates are strongly dependent on the successfully resection of the tumour. In this framework, multimodal optical spectroscopy could provide a fast and label-free tool for improving tumour detection and guiding the removal of diseased tissue. In this study, we used an optical fibre-probe system combining multiple spectroscopic techniques for in vivo examination of normal and GBM tissues in mouse brain. Specifically, the probe – based on a fibre-bundle with optical fibres of various size and properties – allowed performing spectroscopic measurements based on fluorescence, Raman, and diffuse reflectance spectroscopy though two optical windows implanted on the head of each animal. Two visible laser diodes were used for fluorescence spectroscopy, a laser diode emitting in the NIR was used for Raman spectroscopy, and a fibre-coupled halogen lamp for diffuse reflectance. All spectral recordings were done when the animals were anesthetized; optical inspection required less than 4 minutes for each animal. The recorded data were analysed using Principal Component Analysis (PCA) for obtaining an automated classification of the examined tissues based on the intrinsic spectral information provided by Raman and reflectance spectroscopy. The presented method demonstrated high sensitivity and specificity in discriminating GBM from normal brain. Furthermore, we found that the multimodal approach is crucial for improving diagnostic capabilities beyond what can be achieved from individual techniques.

Diagnosis of inflammatory diseases of the paranasal sinuses is one of the urgent problems of modern otolaryngology. Presently, radiography, computed tomography, magnetic resonance imaging, rhinoscopy and ultrasound are used to identify these pathologies. However, due to use of carcinogenic roentgen radiation during the study, a high level of falsenegative results and painfulness of the diagnostic procedures, application of these methods is limited. To overcome these shortcomings, the application of the digital diaphanoscopy method seems to be promising. For realization of this approach the experimental setup was designed and assembled. Low-intensity radiation of the visible and near IR ranges and CMOS-camera were used for translucence of the paranasal sinuses and visualizing the pattern of scattering light. To identify the range of exposure values of the CMOS-camera to obtain maximum sensitivity to identify of pathological changes, experimental studies were conducted on healthy volunteers and patients with inflammatory diseases of paranasal sinuses. During the studies the exposure time of CMOS-camera changed in the range from 0 to 39.7 ms with a step of 1 ms, followed by comparison of the results of digital diaphanoscopy with results of MRI. The results of study 20 volunteers and 15 patients of different genders and ages showed variations in the scattering patterns with the same exposure time. This was explained by such anatomic features as the structure of the skin, the thickness of the skull bone tissue, the size of the sinuses and their asymmetry.

Since plasma proteins are varied depending on diseases states, its continuous monitoring has been considered as effective diagnostic tool. In this study, a simple and efficient method for separate plasma and red blood cells (RBCs) from blood sample is proposed with a microfluidic device. To separate plasma in continuous way, microfluidic guiding channel is designed by connecting two channels with different heights in parallel, and employs inertial force and Zweifach–Fung bifurcation law. Due to its unique geometry, most RBCs flowed inside wall region with higher height. Then, plasma is collected from center region with lower height. As a result, the efficiency of plasma separation is achieved over 90 %. Furthermore, it is remained constant, even up to high value of 40% hematocrit. In the near future, the proposed method will be integrated with a lab-on-a-chip for diagnosing diseases.

The aim of this study is to develop a novel non-invasive approach for skin cancer (melanoma, basal cell and squamous cell carcinomas) diagnostics by mapping the AF intensity decrease (photo-bleaching) rates under continuous 405 nm LED excitation. For parametric mapping of skin AF intensity decrease rates a sequence of filtered AF imaging under 405 nm LED excitation for 20 seconds at a power density of ~7 mW/cm² with a frame rate 0.5 fps was recorded and analyzed by cloud-based prototype device. Several clinical cases and potential future applications of the proposed autofluorescence photobleaching rate imaging technique are discussed.

We report here a comparative study for oral precancer detection using fluorescence spectroscopy on human oral cavity and body fluid saliva. In-vivo detection of oral precancer has been carried out by an in-house developed handheld system and detection on human saliva has been performed by in-house developed compact set-up. The Study has been conducted on three groups of patients: oral squamous cell carcinoma (OSCC), dysplastic (precancer), and control (normal). Fluorescence spectra recorded from oral buccal mucosa (BM) consist of major and minor bands of flavin adenine dinucleotide (FAD) and porphyrins near 500, 634, 689 and 703 nm. Spectra recorded from human saliva also showed the same bands in addition to a new band near 437 nm. Receiver operating characteristic (ROC) analysis has been used to evaluate diagnostic performance. Ratios of the peak values of intensities of porphyrin (634 nm) to FAD (500 nm) bands from the spectra of BM and area under the entire spectra of saliva samples are taken as discriminating parameters to differentiate the groups. Obtained results with human saliva are found to be similar as from BM and we conclude that it may be used as a substitute diagnostic medium of early oral cancer detection.

Monitoring cell culture media by traditional methods has high costs and requires significant analytical expertise and laboratory space. Surface-Enhanced Raman spectroscopy (SERS) can offer a method for a simple and fast analysis of cell culture media under different conditions. In particular, to examine cell culture media during cell exposure to ionizing radiation deserves particular attention. In this way, useful information on the complex processes occurring during the interaction between cells, cell culture media and radiation can be obtained. We report about a SERS study of the radiation-induced changes on cell culture media that were in contact or not with human cells. SERS measurements were performed by using commercial substrates and a conventional micro-Raman spectroscopy set-up. By employing a suitable data treatment based on “wavelet” denoising algorithm and background subtraction, spectra with clear Raman features were obtained for two cell culture media that were subject to different irradiation treatments. The obtained results evidence that SERS can be used to rapidly identify and monitor chemical changes in cell culture media.

Samples of liquid dispersions of 4 μm polystyrene microspheres with cyanine 5 and cyanine 5.5 dyes were synthesized and studied using developed experimental setup for fluorescence microscopy. It was shown the possibility of identification of microspheres with different dyes and different dye concentration in the image. The low coefficient of variation of fluorescence intensity in the image makes it possible to use a large number of types of spectrally encoded microspheres in the immunofluorescence analysis.

Non-invasive diagnostics methods are very helpful for cancer diagnosis and they are a research hotspot in the field of biomedicine. Terahertz (THz) photonics is an emerging technology that can be applied in the field of medical diagnostics. This is due to unique features of THz radiation such as harmlessness to biological tissues, strong absorption by water, ability to identify various biomolecules, etc. In this work we have investigated different types of normal and cancer fresh tissues of the stomach using terahertz time domain spectroscopy in reflection mode. Refractive indices of mucous, serous and tumor stomach tissues were obtained in the frequency range of 0,2 - 1 THz. These optical properties are higher for cancer tissue than for mucosa and lower than for serosa. Thus possibility of discrimination of tumor from normal stomach tissue was demonstrated. This study has practical significance for the field of clinical cancer diagnosis and will help to better understand the specifics of the method of pulsed THz spectroscopy applicable to this field.

In our work, we demonstrate the current results of acetone measurements in exhaled breath using cavity ring down spectrometry for diagnostics of diabetes and other diseases. Our cavity ring down spectrometer is a portable system that works in UV region with the pulsed Nd:YAG laser at 266 nm. Calibration of the system was performed using generated samples by KinTek automated permeation tube system, both, self-prepared and commercial mixtures with known concentration acetone samples in air. In this experiment, we examined breath samples from healthy volunteers and some persons with diabetes before medical treatment.

Last years the development of computer-aided diagnostic systems for medical image analysis has become a hot topic. A key step is connected with informative features extraction. Here, we discussed multiphoton microscopy and optical coherent tomography lymphedema tissue images analysis using gradient processing methods.

Human body mainly consists of muscle, bone and air, and we name penetrating photons the human-body-window (HBW) rays. The HBW spectra were measured using a white power light-emitting diode (LED) and a spectrometer. The photons from the LED penetrate the human body, and reflect, refract and scatter. Therefore, we measured only penetrating HBW spectra from the human body. In the computed tomography (CT), we used a 1.0-mm-diam graphite collimator, two 1.0- mm-diam copper pinholes, and a 1.0-mm-diam aluminum pinhole. The white beam diameter is reduced using the collimator and the first copper pinhole, and the 1.0-mm-diam beam is irradiated to the object. The penetrating HBW photons are selected out using the second copper pinhole behind the object and detected by the photodiode through the aluminum pinhole. HBW-CT is accomplished by repeated translations and rotations of the object. The peak wavelength of the HBW spectra was 610 nm. The translation and rotation steps were 0.25 mm and 1.0º, respectively, and the spatial resolutions were determined as 1.0×1.0 mm2. The scanning time and a total rotation angle for CT were 9.8 min and 180º, respectively.

Modulation interference microscopy is one of the promising technologies for early personalized cancer diagnostics that allow for assessment of the real-time changes of subcellular microstructures with 2D and 3D reconstructions of the images and multifactorial data analysis. Our investigation is aimed to assess the heterogeneity of the CTCs population in patients with breast cancer using modulation interference microscopy (Quantitative Phase Imaging (QPI) technology). Morpho-functional changes in living CD326 (EpCam)+ and Annexin ^V+ cell were measured with a laser modulation interference microscope MIM (PA UOMZ, Russia): height accuracy 0,1 nm, coordinate accuracy 10 nm, image area 1280x1024 pixels, optical magnification 1000, acquisition time 0,3 sec. The complex algorithm included the definition of optic and geometrical characteristics of living cells and , statistical analysis of data and creation of medical documents. We evaluated the functional cellular conditions based on the phase-interference features of their nuclear structures including nucleoli organizer areas which reflect metabolic and proliferative activity of cells and also serve the markers of their malignant transformation.

Publisher’s Note: This paper, originally published on 19 July 2019, was replaced with a corrected/revised version on 4 February 2022. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance.