Aleksei Zhdanov

Mr. Aleksei Zhdanov


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 April 2024 in Scientific Data
Verified
Journal Article
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Mikhail KulyabinMikhail Kulyabin
Mikhail Kulyabin
AZAleksei Zhdanov
Aleksei Zhdanov
ANAnastasia Nikiforova
Anastasia Nikiforova
ASAndrey Stepichev
Andrey Stepichev
AKAnna Kuznetsova
Anna Kuznetsova
AMAndreas Maier
Andreas Maier
Optical coherence tomography (OCT) is a non-invasive imaging technique with extensive clinical applications in ophthalmology. OCT enables the visualization of the retinal layers, playing a vital role in the early detection and monitoring of retinal diseases. OCT uses the principle of light wave interference to create detailed images of the retinal microstructures, making it a valuable tool for diagnosing ocular conditions. This work presents an open-access OCT dataset (OCTDL) comprising over 2000 OCT images labeled according to disease group and retinal pathology. The dataset consists of OCT records of patients with Age-related Macular Degeneration (AMD), Diabetic Macular Edema (DME), Epiretinal Membrane (ERM), Retinal Artery Occlusion (RAO), Retinal Vein Occlusion (RVO), and Vitreomacular Interface Disease (VID). The images were acquired with an Optovue Avanti RTVue XR using raster scanning protocols with dynamic scan length and image resolution. Each retinal b-scan was acquired by centering on the fovea and interpreted and cataloged by an experienced retinal specialist. In this work, we applied Deep Learning classification techniques to this new open-access dataset.

26 October 2023 in Sensors
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Journal Article
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Mikhail KulyabinMikhail Kulyabin
Mikhail Kulyabin
AZAleksei Zhdanov
Aleksei Zhdanov
ADAnton Dolganov
Anton Dolganov
MRMikhail Ronkin
Mikhail Ronkin
VBVasilii Borisov
Vasilii Borisov
AMAndreas Maier
Andreas Maier
The electroretinogram (ERG) is a clinical test that records the retina’s electrical response to light. Analysis of the ERG signal offers a promising way to study different retinal diseases and disorders. Machine learning-based methods are expected to play a pivotal role in achieving the goals of retinal diagnostics and treatment control. This study aims to improve the classification accuracy of the previous work using the combination of three optimal mother wavelet functions. We apply Continuous Wavelet Transform (CWT) on a dataset of mixed pediatric and adult ERG signals and show the possibility of simultaneous analysis of the signals. The modern Visual Transformer-based architectures are tested on a time-frequency representation of the signals. The method provides 88% classification accuracy for Maximum 2.0 ERG, 85% for Scotopic 2.0, and 91% for Photopic 2.0 protocols, which on average improves the result by 7.6% compared to previous work.

19 September 2024 in Bioengineering
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Journal Article
Open access
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Mikhail KulyabinMikhail Kulyabin
Mikhail Kulyabin
AZAleksei Zhdanov
Aleksei Zhdanov
APAndrey Pershin
Andrey Pershin
GSGleb Sokolov
Gleb Sokolov
ANAnastasia Nikiforova
Anastasia Nikiforova
AMAndreas Maier
Andreas Maier
Optical coherence tomography (OCT) is a non-invasive imaging technique widely used in ophthalmology for visualizing retinal layers, aiding in the early detection and monitoring of retinal diseases. OCT is useful for detecting diseases such as age-related macular degeneration (AMD) and diabetic macular edema (DME), which affect millions of people globally. Over the past decade, the area of application of artificial intelligence (AI), particularly deep learning (DL), has significantly increased. The number of medical applications is also rising, with solutions from other domains being increasingly applied to OCT. The segmentation of biomarkers is an essential problem that can enhance the quality of retinal disease diagnostics. For 3D OCT scans, AI is beneficial since manual segmentation is very labor-intensive. In this paper, we employ the new SAM 2 and MedSAM 2 for the segmentation of OCT volumes for two open-source datasets, comparing their performance with the traditional U-Net. The model achieved an overall Dice score of 0.913 and 0.902 for macular holes (MH) and intraretinal cysts (IRC) on OIMHS and 0.888 and 0.909 for intraretinal fluid (IRF) and pigment epithelial detachment (PED) on the AROI dataset, respectively.

28 December 2024 in Bioengineering
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Journal Article
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PAUL CONSTABLEPAUL CONSTABLE
PAUL CONSTABLE
Javier Orlando Pinzon-ArenasJavier Orlando Pinzon-Arenas
Javier Orlando Pinzon-Arenas
LMLuis Roberto Mercado-Diaz
Luis Roberto Mercado-Diaz
ILIrene O Lee
Irene O Lee
Fernando Marmolejo-RamosFernando Marmolejo-Ramos
Fernando Marmolejo-Ramos
Hugo Fernando Posada-QuinteroHugo Fernando Posada-Quintero
Hugo Fernando Posada-Quintero
Electroretinograms (ERGs) show differences between typically developing populations and those with a diagnosis of autism spectrum disorder (ASD) or attention deficit/hyperactivity disorder (ADHD). In a series of ERGs collected in ASD (n = 77), ADHD (n = 43), ASD + ADHD (n = 21), and control (n = 137) groups, this analysis explores the use of machine learning and feature selection techniques to improve the classification between these clinically defined groups. Standard time domain and signal analysis features were evaluated in different machine learning models. For ASD classification, a balanced accuracy (BA) of 0.87 was achieved for male participants. For ADHD, a BA of 0.84 was achieved for female participants. When a three-group model (ASD, ADHD, and control) the BA was lower, at 0.70, and fell further to 0.53 when all groups were included (ASD, ADHD, ASD + ADHD, and control). The findings support a role for the ERG in establishing a broad two-group classification of ASD or ADHD, but the model’s performance depends upon sex and is limited when multiple classes are included in machine learning modeling.

9 April 2024 in IEEE Access
Verified
Journal Article
Open access
Mikhail KulyabinMikhail Kulyabin
Mikhail Kulyabin
PAUL CONSTABLEPAUL CONSTABLE
PAUL CONSTABLE
AZAleksei Zhdanov
Aleksei Zhdanov
ILIrene O Lee
Irene O Lee
DTDorothy Thompson
Dorothy Thompson
AMAndreas Maier
Andreas Maier
The electroretinogram (ERG) is a clinical test that records the retina’s electrical response to a brief flash of light as a waveform signal. Analysis of the ERG signal offers a promising non-invasive method for studying different neurodevelopmental and neurodegenerative disorders. Autism Spectrum Disorder (ASD) is a neurodevelopmental condition characterized by poor communication, reduced reciprocal social interaction, and restricted and repetitive stereotyped behaviors that should be detected as early as possible to ensure timely and appropriate intervention to support the individual and their family. In this study, we applied gated Multilayer Perceptron (gMLP) for the light-adapted ERG waveform classification as an effective alternative to Transformers. This study presents the first application of gMLP for ASD classification, which employs basic multilayer perceptrons with fewer parameters than Transformers. We compared the performance of different time-series models on an ASD-Control dataset and found that the superiority of gMLP in classification accuracy was the best at 89.7% compared to alternative models and supports the use of gMLP in classification models based on ERG recordings involving case-control comparisons.

2 December 2022 in Applied Sciences
Verified
Journal Article
Open access
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AZAleksei Zhdanov
Aleksei Zhdanov
ADAnton Dolganov
Anton Dolganov
DZDario Zanca
Dario Zanca
VBVasilii Borisov
Vasilii Borisov
MRMikhail Ronkin
Mikhail Ronkin
The electroretinography (ERG) is a diagnostic test that measures the electrical activity of the retina in response to a light stimulus. The current ERG signal analysis uses four components, namely amplitude, and the latency of a-wave and b-wave. Nowadays, the international electrophysiology community established the standard for electroretinography in 2008. However, in terms of signal analysis, there were no major changes. ERG analysis is still based on a four-component evaluation. The article describes the ERG database, including the classification of signals via the advanced analysis of electroretinograms based on wavelet scalogram processing. To implement an extended analysis of the ERG, the parameters extracted from the wavelet scalogram of the signal were obtained using digital image processing and machine learning methods. Specifically, the study focused on the preprocessing of wavelet scalogram as images, and the extraction of connected components and thier evaluation. As a machine learning method, a decision tree was selected as one that incorporated feature selection. The study results show that the proposed algorithm more accurately implements the classification of adult electroretinogram signals by 19%, and pediatric signals by 20%, in comparison with the classical features of ERG. The promising use of ERG is presented using differential diagnostics, which may also be used in preclinical toxicology and experimental modeling. The problem of developing methods for electrophysiological signals analysis in ophthalmology is associated with the complex morphological structures of electrophysiological signal components.