Viktor Dremin

Aston University · Aston Institute of Photonic Technologies

We developed a compact, hand-held hyperspectral imaging system for 2D neural network-based visualization of skin chromophores and blood oxygenation. State-of-the-art micro-optic multichannel matrix sensor combined with the tunable Fabry-Perot micro interferometer enables a portable diagnostic device sensitive to the changes of the oxygen saturation...

Recent advances in the development of ultra-compact semiconductor lasers and technology of printed flexible hybrid electronics have opened broad perspectives for the design of new pulse oximetry and photoplethysmography devices. Conceptual design of optical diagnostic devices requires careful selection of various technical parameters, including spe...

The prevalence of diabetes complications is a significant public health problem with a considerable economic cost. Thus, the timely diagnosis of complications and prevention of their development will contribute to increasing the length and quality of patient life, and reducing the economic costs of their treatment. This article aims to review the c...

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...

Aging and diabetes lead to protein glycation and cause dysfunction of collagen-containing tissues. The accompanying structural and functional changes of collagen significantly contribute to the development of various pathological malformations affecting the skin, blood vessels, and nerves, causing a number of complications, increasing disability ri...

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.

The fabrication of artificial tissue and organ models is one of the important directions of the development of modern biomedicine. Assessment of the morphology, maturation, and viability is an important part of such developments. Here, we report on the validation of our custom-build fluorescence spectroscopy (FS) system with optical coherence tomog...

This study contains analysis of existing approaches for detecting photosensitizer-free laser-induced singlet oxygen, including their ability to quantitatively measure the relationship between a dose of laser radiation and the amount of singlet oxygen produced.

Current medicine might be greatly enhanced by the ability to in vivo control and monitor neurons using opsins/phytochromes expressed in neural cells. The fundamental challenge with non-invasive neural cell activity regulation is a high absorption of visible light into biological tissues. This drawback could be mitigated by the photoconversion of ph...

This work investigates the influence of laser irradiation parameters (wavelength, power density and exposure time) on singlet oxygen (1O2) generation efficiency. Chemical trap (L-histidine) and fluorescent probe (Singlet Oxygen Sensor Green, SOSG) detection methods were used. Studies have been conducted for 1267, 1244, 1122 and 1064 nm laser wavele...

Bulk tissue polarimetry is a promising method for label-free imaging of biological samples utilizing naturally accrued polarization contrast of structural tissue composition exploiting vector nature of the light. Besides, the hyperspectral imaging is an emerging diagnostic modality widely used for functional tissue characterization. We develop an a...

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...

The process and results of numerical Monte Carlo simulation of optical radiation propagation in laser Doppler flowmetry and fluorescence spectroscopy channels of a wearable diagnostic multimodal device are described in this paper. To achieve the goal, a multilayer skin model with different parameters of blood and melanin content and different dista...

Maxillary sinus pathologies remain among the most common ENT diseases requiring timely diagnosis for successful treatment. Standard ENT inspection approaches indicate low sensitivity in detecting maxillary sinus pathologies. In this paper, we report on capabilities of digital diaphanoscopy combined with machine learning tools in the detection of su...

Editorial of the Special Issue: Lesion Detection and Analysis Using Optical Imaging (https://www.mdpi.com/journal/diagnostics/special_issues/Lesion_Optical_Imaging).

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...

Optogenetic control of neuronal activity requires efficient light energy transmission through head tissues and bone. Here we evaluate the efficiency of ultrashort pulsed and continuous-wave light transmittance through the mouse scalp, skull, and brain tissues in near-IR optical windows. The outcomes of the experiments and computer modelling show th...

Our healthy lifestyle requires a personalized healthy diet and balanced physical activities. All of these will in principle be possible with personal trainers and dietologists. Why the development of continuous monitoring of human health and activity wireless wearable devices will be one of the key technologies in the ubiquitous sensor network soci...

In recent years, there has been increasing interest in the singlet form of oxygen as a regulator of the physiological functions of cells. The use of photosensitisers is a classical mechanism for the excitation of the main triplet form of oxygen and the generation of its singlet form. At the same time, it has been shown that there is a possibility o...

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...

The theory of rheology of non-Newtonian fluids is based on the generalized Newtonian hypothesis of viscosity. The viscometers for non-Newtonian fluids should implement fluid flows with the known stress and strain state parameters distributions. Ideally, the distributions should be homogeneous in the flow domain. The idea of the proposed method is b...

We present a prototype and verification of a multichannel laser system applicable to optogenetic research. In vivo photostimulation of neural cells expressing photoconvertible phytochromes or opsins requires enough light irradiation delivery to the brain that cannot be supported by continues-wave (CW) light sources. The use of ultra-short pulsed...

Diabetes leads to protein glycation and causes dysfunction of collagen-containing tissues. The accompanying structural and functional changes of collagen significantly contribute to the development of various pathological malformations affecting the skin, blood vessels, and nerves, causing a number of complications, increasing disability risks and...

Assessment of biological tissues’ intrinsic fluorescence provides unique perspectives for the development of new methods of optical noninvasive diagnostics for application in many fields of medicine. Fluorescence techniques alone or together with other biophotonics methods have found their application in oncology, surgery, dermatology, etc. This ch...

Purpose of research . Development of theoretical premises for the new inertial viscometer, as well as the development of an approximate model of the viscosity fluid flow using convolutional neural networks and laser speckle contrast imaging data. Methods . The study consists of two parts. The first is devoted to a theoretical study of viscosity flu...

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...

Nowadays, photonics-based techniques are used extensively in various applications, including functional clinical diagnosis, progress monitoring in treatment, and provision of metrological control. In fact, in the frame of practical implementation of optical methods, such as laser Doppler flowmetry (LDF), the qualitative interpretation and quantitat...

Optogenetic research has opened up the possibility to control neurons that will help detect and treat neurological diseases in the early stage. Treatment of dysfunctions requires exposure to a partial neural network accessible through the absorption of opsins or phytochromes expressed in the brain matter. The use of II-NIR USP lasers makes it possi...

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...

An approach to visualization of the vascular bed with the possibility of assessing changes in blood filling and identifying diagnostically significant periodic changes in the signal by analyzing speckle images is proposed. The effect of singlet oxygen by direct excitation of an oxygen molecule by 1267 nm laser radiation on changes in the vascular b...

In recent years, there has been a growing interest in the singlet form of oxygen as a regulator of the physiological functions of cells. One of the ways to generate singlet oxygen is direct optical excitation of the triplet oxygen form. Since molecular oxygen weakly absorbs light, high power is required to obtain sufficient concentrations of single...

The paper presents the results of a study of conditionally healthy volunteers and patients with various maxillary sinuses diseases by digital diaphanoscopy with a comparison of the results obtained with CT studies. The results of the classification of pathological changes based on a quantitative assessment of the registered scattering patterns of l...

Advances in the development of ultra-compact semiconductor lasers have opened up new possibilities for the development of wearable devices implementing biophotonic technologies, such as laser Doppler flowmetry (LDF) and fluorescence spectroscopy (FS). This work is aimed to evaluate the correlation between diagnostic parameters simultaneously regist...

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 paper deals with processing data obtained using nailfold high-speed videocapillaroscopy. To detect the red blood cells velocity two approaches are used. The deterministic approach is based on pixel intensities analysis for object detection and calculation of the displacement and velocity of red blood cells in a capillary. The obtained data form...

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...

The interaction of laser radiation of wavelengths of direct optical generation of singlet oxygen with cell culture media was simulated. Using the COMSOL Multiphysics software, the distribution of the thermal field over the culture media volume was obtained depending on the wavelength, power and exposure time. The results demonstrate the importance...

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...

In biophotonics, novel techniques and approaches are being constantly sought to assist medical doctors and to increase both sensitivity and specificity of the existing diagnostic methods. In such context, tissue polarimetry holds promise to become a valuable optical diagnostic technique as it is sensitive to tissue alterations caused by different b...

Regretfully, because of her sudden demise, Assoc. Prof. Ekaterina Borisova is no longer amongst us. COVID-19 pulled away a brilliant scientist during the peak of her scientific career (see Fig. 1). All authors would like to express deepest condolences and sincere support to her family, friends, relatives and colleagues! We, therefore, rightfully co...

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...

Despite the fact that both acute cardiac cessation and respiratory arrest are the reasons of brain ischemia, its hemodynamics, oxygenation and structural pathology differs. This article represents blood re-distribution and neuronal tissue degeneration during the first decade of minutes after the breathing and heart beating violation. The results sh...

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 work, the LED applicator brightness control unit of the digital diaphanoscope was upgraded, which allows adjusting of the radiation power value in a wide range for patient's study, considering anatomical and gender features.

We introduce a high-resolution polarization imaging approach for automatic stand-alone classification of the unstained breast cancer tissue blocks by using K-means cluster analysis of the Stokes vectors projected on the Poincaré sphere.

Understanding of acute respiratory pathology is critically important. We assess dynamics of cerebral cortex blood flow and tissue changes at the pathology in rats. Rapid blood flow centralization and irreversible brain tissue lesions are observed.

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 impairments of cerebral blood flow microcirculation brought on by cardiac and respiratory arrest were assessed with multi-modal diagnostic facilities, utilising laser speckle contrast imaging, fluorescence spectroscopy and diffuse reflectance spectroscopy. The results of laser speckle contrast imaging show a notable reduction of cerebral blood...

Purpose of research. Development of a technique for estimating the average flow rate of physiological fluids in capillaries from images obtained using laser speckle-contrast imaging. The technique includes obtaining experimental data in the form of an image of the fluid flow in a thin tube, their preliminary processing, including filtering and comp...

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...

Brain is one of the most energy-demanding organs. Energy in the form of ATP is produced in brain cells predominantly in oxidative phosphorylation coupled to mitochondrial respiration. Any alteration of the mitochondrial metabolism or prolonged ischemic or anoxic conditions can lead to serious neurological conditions, including neurodegenerative dis...

Brain is one of the most energy-demanding organs. Energy in the form of ATP is produced in brain cells predominantly in oxidative phosphorylation coupled to mitochondrial respiration. Any alteration of the mitochondrial metabolism or prolonged ischemic or anoxic conditions can lead to serious neurological conditions, including neurodegenerative dis...

Tissue polarimetry holds great promise to improve the effectiveness of conventional cancer diagnostics and staging, being a fast, minimally invasive, and low-cost optical technique. We introduce an enhanced diagnostic method for ex vivo colon specimens assessment by utilizing Stokes and Mueller matrix polarimetry. The proposed method makes use of e...

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...

In this paper the optical properties of the purulent content of the maxillary sinuses were obtained by spectrophotometry. Based on the obtained absorption and reduced scattering coefficients, a numerical simulation by Monte Carlo method was performed to determine the pattern of light scattering passing through the maxillary sinus with purulent cont...

Tissue polarimetry could be identified as a complementary optical and non-invasive technique to assist the gold standard histopathology analysis of tissue. In general, polarimetric diagnostics is based on tracing different polarimetric responses (including light depolarization) in tissue zones with structure altered by the benign and pre/cancerous...

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...

The work is devoted to the development of a scientific and technical basis for instrument implementation of a digital diaphanoscopy technology for the diagnosis of maxillary sinus inflammatory diseases taking into account the anatomical features of patients (differences in skin structure, skull bone thickness, and sinus size), the optical propertie...