Elena Potapova

Orlov State University · Scientific-educational center «Biomedical engineering»

Objectives One of the widely used optical biopsy methods for monitoring cellular and tissue metabolism is time-resolved fluorescence. The use of this method in optical liver biopsy has a high potential for studying the shift in energy-type production from oxidative phosphorylation to glycolysis and changes in the antioxidant defense of malignant ce...

A multimodal device for assessing the metabolic status of tissues during minimally invasive surgeries is proposed. The hardware and software system and specially developed fine-needle fiber-optic probes support assessment of the fluorescence of the main tissue fluorophores, as well as tissue saturation. The approach proposed here addresses a number...

The effects of the interaction of optical radiation and biological tissues underlie various optical diagnostics technologies, including laser Doppler flowmetry, diffuse reflection spectroscopy, fluorescent spectroscopy, photodynamic diagnostics (fluorescent cystoscopy), confocal microscopy, optical coherence tomography, etc. The efficiency of these...

Timely detection and prognosis of liver failure play an important role in improving treatment outcomes for patients with biliary obstruction. The study describes the use of optical biopsy methods to determine the functional state of the liver in patients with obstructive jaundice syndrome during and after antegrade biliary decompression. Fluorescen...

Microscopic images of cells often contain multiple objects with similar properties. In this study, we collected videos of blood microcirculation in nailfold capillaries to identify correlations between video data and indicators of complete blood count tests. The specific features of these videos include a high number of capillaries and a high varia...

The fluorescence intensities of the cellular respiratory cofactors NADH (reduced nicotinamide adenine dinucleotide) and FAD++ (oxidized flavin adenine dinucleotide) reflect energy metabolism in skin and other tissues and can be quantified in vivo by fluorescence spectroscopy (FS). However, the variability of physiological parameters largely determi...

Animal models mimicking human transient ischemic attack (TIA) and cerebral microinfarcts are essential tools for studying their pathogenetic mechanisms and finding methods of their treatment. Despite its advantages, the model of single arteriole photothrombosis requires complex experimental equipment and highly invasive surgery, which may affect th...

Introduction . Breast cancer (BC) is the most common malignant tumor in women worldwide. It amounts more than 16 % of all cases of malignant neoplasms in women. Modern advances in radiological methods of breast tumors detection significantly increased the number of non-palpable neoplasms revealed during examinations, while further progress requires...

This paper presents a microscopic diagnostic system that combines hyperspectral and frequency domain fluorescence lifetime imaging to record the content of chromophores and highspeed changes in cell and tissue metabolism. The efficiency of the system was tested on liver tumor slices of a laboratory mouse.

This paper presents the results of investigating the blood flow dynamics using the laser speckle contrast imaging method in rats with blood loss and without it. The results indicate that under such conditions, there was no significant decrease in speckle perfusion values.

This work reports a machine-learning-based approach to interpret time-resolved fluorescence spectroscopy data acquired during optical biopsy of the liver. The approach allowed to differentiate between liver parenchyma and tumor with sensitivity and specificity above 0.91 and 0.79, respectively, providing differential diagnosis of liver cancer (prim...

The development of modern technologies, tendencies to reduce traumatization and extent of surgical interventions have created conditions for intensive implementation and widespread use of minimally invasive surgery (MIS). For all their advantages, MIS interventions have a number of peculiarities, primarily related to limited access to the organ. Th...

Neurodegenerative diseases are chronic conditions occurring when neurons die in specific brain regions that lead to loss of movement or cognitive functions. Despite the progress in understanding the mechanisms of this pathology, currently no cure exists to treat these types of diseases: for some of them the only help is alleviating the associated s...

Profound changes in the metabolism of cancer cells have been known for almost 100 years, and many aspects of these changes have continued to be actively studied and discussed. Differences in the results of various studies can be explained by the diversity of tumours, which have differing processes of energy metabolism, and by limitations in the met...

Background. Acute intestinal ischemia is a disease characterized by a violation of blood supply, which leads to hypoxia of intestinal wall tissues and secondary pathological changes. One of the main factors determining the urgency of the problem of acute intestinal ischemia is the intraoperative determination of the viability of the intestinal wall...

Breast cancer is the most common malignant disease in women worldwide. According to the World Health Organization and the International Agency for Research on Cancer, it accounts for 25.1% of all cancer cases in women. Intracystic breast cancer is one of the most rare and difficult to diagnose forms of this disease. Due to this improving existing m...

BACKGROUND: Despite an enormous progress in the field of reproductive endocrinology, the mechanisms of premature ovarian insufficiency have not been fully understood so far. Knowledge of the supposed causes and mechanisms underlying the development of premature ovarian insufficiency has expanded significantly in recent years, mainly due to advances...

Introduction. Diseases accompanied by a violation of the blood supply to the intestinal wall occupy one of the main places in urgent surgery of the abdominal organs. Intraoperative assessment of intestinal viability is one of the most difficult tasks and plays a leading role in determining the volume of surgical aid, predicting the course of the po...

This study presents a hyperspectral optical imaging system for the diagnosis of infantile hemangiomas. Pilot studies were conducted in the clinic on infants. As the main results, the parameters of blood flow and saturation of the areas with hemangiomas were calculated using a previously developed neural network approach. The results indicate the po...

This work shows the application of LSCI for mapping the cerebral vessels of a laboratory animal, and also presents the time-frequency processing of the registered signal. Thus, we expand the capabilities of the existing LSCI approach and demonstrate spatial mapping of blood flow fluctuations.

Modern preclinical and clinical studies show that the use of diagnostic methods based on the registration of fluorescent radiation can improve the early diagnosis of cancer and other destructive processes of various organs. Currently, many studies are being conducted aimed at studying the processes of oxidative metabolism using methods that registe...

Objectives: Currently, one of the most pressing issues for surgeons in the treatment of obstructive jaundice is the ability to assess the functional state of the liver and to detect and determine the degree of liver failure in a timely manner with simple and objective techniques. In this regard, the use of fluorescence spectroscopy method can be c...

BACKGROUND:Uterine fibroids are the most common benign tumor of the female reproductive system. A number of factors affect endometrial receptivity in patients with uterine fibroids such as transcription factorsHOXA10andHOXA11, cytokines (growth factors and inflammatory markers), etc. The negative effect of myomatous nodes, which deform the uterine...

Improving noninvasive approaches to monitoring blood microcirculation is an urgent topic in modern biomedical engineering. One of the actively developing methods is laser speckle contrast imaging (LSCI), which allows not only the visualization of microvessels but also the quantitative measurements of microcirculatory blood flow. This work shows the...

Previous studies have shown that intraoperative optical diagnostics can be used to solve fundamental and applied problems in gynecology. Our article presents results from experimental in vivo intraoperative measurements of endogenous fluorescence and blood perfusion in various sections of the uterus, myometrium, endometrium, myomas, and pseudocapsu...

Modern photonics methods are considered in relation to solving a number of diagnostic problems in practical medicine. The basic principles of the application of optical noninvasive diagnostic methods are described and examples are given: laser Doppler flowmetry, digital diaphanoscopy, Raman spectroscopy, spectrophotometry, time-resolved fluorescenc...

In this work, we demonstrate the results of measuring the optical properties of rat liver tissue slices after the liver itself underwent the perfusion procedure with an isotonic solution. The approach is suggested as a means to attenuate the influence of blood absorption on recorded characteristics and demonstrates its effectiveness in changing the...

Blood microcirculation plays a key role in maintaining tissue homeostasis and is involved in the pathological process in the early stages of the diabetes, leading to severe and difficult-to-treat complications in the future. Vascular tone regulation is an important feature of microvessels and underpins the performance of numerous functions of micro...

Singlet oxygen (1O2) is an electronically excited state of triplet oxygen which is less stable than molecular oxygen in the electronic ground state and produced by photochemical, thermal, chemical, or enzymatic activation of O2. Although the role of singlet oxygen in biology and medicine was intensively studied with photosensitisers, using of these...

At the moment, percutaneous needle biopsy (PNB) remains the gold standard for diagnosing liver cancer. However, the relatively high probability of false-negative results can still be an issue with the method. The introduction of real-time feedback for the precise navigation of the biopsy tool is an up-and-coming technology to immensely reduce the m...

This article presents a liquid phantom technology that simulates the fluorescent properties of protoporphyrin IX (PPIX). A technology was developed for the isolation of PPIX from dark egg shells with a final concentration close to the real values in human tissues. A comparative analysis of the transmittance coefficient of the manufactured phantom a...

The aim of this work is to develop practical tools to recognize the average flow rate of physiological fluids in capillaries. This tool is represented by classification models in an artificial neural networks form. The flow rate data were obtained experimentally. Intralipid was used as the test liquid. Laser speckle contrast imaging was used to obt...

In this work, we propose the results of pilot studies on using the modulated CMOS camera for the imaging of autofluorescence in murine hepatocellular carcinoma cells with excitation in UV light. Here, we assess the capabilities of the imaging system to detect changes in the NAD(P)H fractions produced and utilised in the glycolysis, pentose phosphat...

Neurodegenerative disorders are currently incurable devastating diseases which are characterized by the slow and progressive loss of neurons in specific brain regions. Progress in the investigation of the mechanisms of these disorders helped to identify a number of genes associated with familial forms of these diseases and a number of toxins and ri...

This work presents results of in vivo and in situ measurements of hepatocellular carcinoma by a developed optical biopsy system. Here, we describe the technical details of the implementation of fluorescence lifetime and diffuse reflectance measurements by the system, equipped with an original needle optical probe, compatible with the 17.5G biopsy n...

The article presents the results of studies of the melanin effect on recorded signals in laser Doppler flowmetry (LDF) and tissue reflectance oximetry (TO). By investigating the properties of recorded microvascular blood flow and skin oxygenation signals, we have gained new knowledge about race-related differences in the formation of these signals....

The article describes a multiparametric approach to the assessment of cutaneous microcirculation in dermatological patients (using the example of psoriasis patients). The multiparametric diagnostic approach consisted of three stages of successive measurements performed according to the methodology of laser speckle contrast imaging (LSCI), laser Dop...

Due to the widespread introduction of laparoscopic studies into modern surgical practice, the task of objectifying the obtained data and expanding the opportunities for obtaining additional diagnostic information is urgent. In this work, we develop the first-of-its-kind multimodal laparoscopic system integrating hyperspectral, fluorescence, and las...

In this paper we demonstrate results of combined measurements by diffuse reflectance and fluorescence lifetime measuring techniques for real time liver cancer differentiation using a needle optical probe.

The laser speckle contrast imaging allows the determination of the flow motion in a sequence of images. The aim of this study is to combine the speckle contrast imaging and machine learning methods to recognition of physiological fluids flow rate. Data on the flow of intralipid with average flow rate of 0-2 mm/s in a glass capillary were obtained u...

LSCI technique provides experimental data which can be considered in the context of spatial blood flow coherency. Analysis of vascular tone oscillations gives additional information to ensure a better understanding of the mechanisms affecting microvascular physiology. The oscillations with different frequencies are due to different physiological me...

Based on the combined use of polymerisable polyacrylamide, collagen and an aqueous solution of flavin adenine dinucleotide (FAD), we have developed a new technique for fabrication of composite phantoms mimicking fluorescence properties of human skin. A comparative analysis of the absorption and scattering coefficients, refractive indices, as well a...

A flexible fibre optical probe is implemented to record the parameters of the endogenous fluorescence during minimally invasive interventions in patients with cancers of hepatoduodenal area. Using machine learning techniques, the obtained spectra are classified to indicate cancerous or healthy tissue. For this, a set of different binary classifiers...

Abdominal cancer is a widely prevalent group of tumours with a high level of mortality if diagnosed at a late stage. Although the cancer death rates have in general declined over the past few decades, the mortality from tumours in the hepatoduodenal area has significantly increased in recent years. The broader use of minimal access surgery (MAS) fo...

The aspects of using optical instruments for minimally invasive interventions in abdominal surgery are considered. The results of clinical and preclinical trials of the application of the multimodal optical approaches in endoscopic instruments for the treatment and diagnosis of abdominal cancer are reviewed and discussed. A significant increase in...

This paper describes the experimental monitoring of pancreatic oxidative metabolism in laboratory mice that combines the methods of fluorescence and diffuse reflectance spectroscopy and laser speckle contrast imaging with a pancreatic ischemia model. The combined measurements show a close dependence of tissue metabolism on blood and oxygen supply....

Liver cancer remains one of the most widespread cancer types worldwide. The time spent on the diagnosis is one of crucial factors ensuring the effectiveness of treatment. As percutaneous needle biopsy remains the gold standard for liver diagnosis, it is necessary to develop new methods for improving this procedure. One of the most promising directi...

This paper presents the results of the experiments which were performed using the optical biopsy system specially developed for in vivo tissue classification during the percutaneous needle biopsy (PNB) of the liver. The proposed system includes an optical probe of small diameter acceptable for use in the PNB of the liver. The results of the feasibi...

A device for optical biopsy with a fluorescence spectroscopy channel and a fine-needle optical probe for use in fine-needle aspiration biopsy of liver tumors is described. To test the developed device, experimental measurements of the fluorescence of internal organs of a laboratory rat were carried out in vivo while exposing the tissue surface to m...

Aggregation of the misfolded proteins β-amyloid, tau, huntingtin, and α-synuclein is one of the most important steps in the pathology underlying a wide spectrum of neurodegenerative disorders, including the two most common ones—Alzheimer's and Parkinson's disease. Activity and toxicity of these proteins depends on the stage and form of aggregates....

The article describes the development of the optical phantom mimicking flavin adenine dinucleotide (FAD) and skin collagen fluorescence. The results of experimental studies using fluorescence imaging and fluorescence spectroscopy methods are demonstrated. The method of optical phantom production for quick calibration of fluorescence imaging devices...

To determine optimal lighting conditions for contrast imaging of surgical objects, optical characteristics of biological tissues and spectral characteristics of smart light "LED light" source based on RGBW LED are compared. The spectral characteristics of tissues and organs have been investigated. Optimal lighting conditions for contrast imaging of...

The paper describes the results of experimental studies using custom developed optical biopsy system for diagnostics in vivo during the procedure of fine needle aspiration biopsy. Experimental studies were conducted in laboratory mice with inoculated hepatocellular carcinoma. The measurements were carried out using fluorescence spectroscopy and dif...

The possibility of using a multi-modal approach in the clinical practice of a dermatologist for psoriasis, which includes 3 optical non-invasive technologies: laser Doppler flowmetry, video capillaroscopy, and laser speckle-contrast imaging, is demonstrated. The dynamics of changes in the main microhemodynamic parameters of the microcirculatory bed...

Currently, optical biopsy is a promising area of diagnosing the state of tissues in real time during the surgical treatment of oncological diseases. The important part of this direction is the development of fluorescence imaging systems and ensuring the accuracy of the calibration of optical measurements. The article describes the development of fl...

Laser speckle contrast imaging of the microcirculatory bed of the pancreas is performed, which allows its condition to be assessed and thereby is an additional valuable tool for making a diagnostic decision and dynamically monitoring the effectiveness of the treatment for pathology of the abdominal organs. Laparoscopic operations on the pancreas ar...

During surgery, it is important for the surgeon to determine the optimal lighting conditions for contrast imaging of the operated objects. The paper analyzes various parameters of a controlled colour-dynamic surgical lamp based on a powerful led when contrasting individual organs and tissues of model animals, as well as optical parameters of the or...

Objective: Spectral analysis of laser Doppler flowmetry (LDF) signals has been widely used in studies of physiological vascular function regulation. An alternative to LDF is the laser speckle contrast imaging method (LSCI), which is based on the same physical principle. In contrast to LDF, LSCI provides non-scanning full-field imaging of a relativ...

Presently, in the modern laser Doppler flowmetry (LDF) the distribution of blood perfusion and its changes along the Doppler shift frequencies are simply ignored and/or not properly addressed. Utilizing the registered power spectrum of photocurrent, we introduce an LDF signal processing approach suitable for expanding of diagnostic capabilities of...

The paper describes the methodology and technical implementation of a multimodal approach for optical diagnostics in hepatopancreatobiliary organs focal and diffuse neoplasms. Fine needle aspiration biopsy technique and following cytological examination show its effectiveness and safety but its performing takes several days. However, the problem of...

The variation of blood flow characteristics caused by the probe pressure during noninvasive studies is of particular interest within the context of fundamental and applied research. It has been shown previously that the weak local pressure induces vasodilation, whereas the increased pressure is able to stop the blood flow in the compressed area, as...

The problem of diabetes (DM) has attracted scientists of different specialties, as its prevalence is increasing worldwide and assumes the character of a pandemic. Recent studies have noted that timely diagnosis and treatment, including increasing patient control, reduces complications of DM and makes it possible to reverse their development if dete...

Fine needle aspiration biopsy technique and following histological examination show its effectiveness and safety but its performing takes several time. However, the problem of real-time analysis of pathological changes in tissues remains relevant. We demonstrate optical fine-needle biopsy method, combining a fine needle (17.5G) and a fiber-optic pr...