Andrejs Bondarenko

Dr. Andrejs Bondarenko


Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

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

Representative Publications

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9 October 2023 in Sensors
Verified
Journal Article
Open access
PDF file
Vilen JumutcVilen Jumutc
Vilen Jumutc
ASArtjoms Suponenkovs
Artjoms Suponenkovs
ABAndrejs Bondarenko
Andrejs Bondarenko
DBDmitrijs Bliznuks
Dmitrijs Bliznuks
ALAlexey Lihachev
Alexey Lihachev
Colony-Forming Unit (CFU) counting is a complex problem without a universal solution in biomedical and food safety domains. A multitude of sophisticated heuristics and segmentation-driven approaches have been proposed by researchers. However, U-Net remains the most frequently cited and used deep learning method in these domains. The latter approach provides a segmentation output map and requires an additional counting procedure to calculate unique segmented regions and detect microbial colonies. However, due to pixel-based targets, it tends to generate irrelevant artifacts or errant pixels, leading to inaccurate and mixed post-processing results. In response to these challenges, this paper proposes a novel hybrid counting approach, incorporating a multi-loss U-Net reformulation and a post-processing Petri dish localization algorithm. Firstly, a unique innovation lies in the multi-loss U-Net reformulation. An additional loss term is introduced in the bottleneck U-Net layer, focusing on the delivery of an auxiliary signal that indicates where to look for distinct CFUs. Secondly, the novel localization algorithm automatically incorporates an agar plate and its bezel into the CFU counting techniques. Finally, the proposition is further enhanced by the integration of a fully automated solution, which comprises a specially designed uniform Petri dish illumination system and a counting web application. The latter application directly receives images from the camera, processes them, and sends the segmentation results to the user. This feature provides an opportunity to correct the CFU counts, offering a feedback loop that contributes to the continued development of the deep learning model. Through extensive experimentation, the authors of this paper have found that all probed multi-loss U-Net architectures incorporated into the proposed hybrid approach consistently outperformed their single-loss counterparts, as well as other comparable models such as self-normalized density maps and YOLOv6, by at least 1% to 3% in mean absolute and symmetric mean absolute percentage errors. Further significant improvements were also reported through the means of the novel localization algorithm. This reaffirms the effectiveness of the proposed hybrid solution in addressing contemporary challenges of precise in vitro CFU counting.

3 February 2025 in Diagnostics
Verified
Journal Article
Open access
PDF file
LRLaura Rey-Barroso
Laura Rey-Barroso
MVMeritxell Vilaseca
Meritxell Vilaseca
Santiago RoyoSantiago Royo
Santiago Royo
FDFernando Díaz Doutón
Fernando Díaz Doutón
ILIlze Lihacova
Ilze Lihacova
FBFrancisco Burgos
Francisco Burgos
An estimated 60,000 people die annually from skin cancer, predominantly melanoma. The diagnosis of skin lesions primarily relies on visual inspection, but around half of lesions pose diagnostic challenges, often necessitating a biopsy. Non-invasive detection methods like Computer-Aided Diagnosis (CAD) using Deep Learning (DL) are becoming more prominent. This study focuses on the use of multispectral (MS) imaging to improve skin lesion classification of DL models. We trained two convolutional neural networks (CNNs)—a simple CNN with six two-dimensional (2D) convolutional layers and a custom VGG-16 model with three-dimensional (3D) convolutional layers—using a dataset of MS images. The dataset included spectral cubes from 327 nevi, 112 melanomas, and 70 basal cell carcinomas (BCCs). We compared the performance of the CNNs trained with full spectral cubes versus using only three spectral bands closest to RGB wavelengths. The custom VGG-16 model achieved a classification accuracy of 71% with full spectral cubes and 45% with RGB-simulated images. The simple CNN achieved an accuracy of 83% with full spectral cubes and 36% with RGB-simulated images, demonstrating the added value of spectral information. These results confirm that MS imaging provides complementary information beyond traditional RGB images, contributing to improved classification performance. Although the dataset size remains a limitation, the findings indicate that MS imaging has significant potential for enhancing skin lesion diagnosis, paving the way for further advancements as larger datasets become available.

15 May 2025 in Diagnostics
Verified
Journal Article
Open access
PDF file
ABAndrejs Bondarenko
Andrejs Bondarenko
Vilen JumutcVilen Jumutc
Vilen Jumutc
ANAntoine Netter
Antoine Netter
FDFanny Duchateau
Fanny Duchateau
HAHenrique Mendonca Abrao
Henrique Mendonca Abrao
DBDmitrijs Bliznuks
Dmitrijs Bliznuks
Background: Laparoscopic surgery for endometriosis presents unique challenges due to the complexity of and variability in lesion appearances within the abdominal cavity. This study investigates the application of deep learning models for object detection in laparoscopic videos, aiming to assist surgeons in accurately identifying and localizing endometriosis lesions and related anatomical structures. A custom dataset was curated, comprising of 199 video sequences and 205,725 frames. Of these, 17,560 frames were meticulously annotated by medical professionals. The dataset includes object detection annotations for 10 object classes relevant to endometriosis, alongside segmentation masks for some classes. Methods: To address the object detection task, we evaluated the performance of two deep learning models—FasterRCNN and YOLOv9—under both stratified and non-stratified training scenarios. Results: The experimental results demonstrated that stratified training significantly reduced the risk of data leakage and improved model generalization. The best-performing FasterRCNN object detection model achieved a high average test precision of 0.9811 ± 0.0084, recall of 0.7083 ± 0.0807, and mAP50 (mean average precision at 50% overlap) of 0.8185 ± 0.0562 across all presented classes. Despite these successes, the study also highlights the challenges posed by the weak annotations and class imbalances in the dataset, which impacted overall model performances. Conclusions: In conclusion, this study provides valuable insights into the application of deep learning for enhancing laparoscopic surgical precision in endometriosis treatment. The findings underscore the importance of robust dataset curation and advanced training strategies in developing reliable AI-assisted tools for surgical interventions. The latter could potentially improve the guidance of surgical interventions and prevent blind spots occurring in difficult to reach abdominal regions. Future work will focus on refining the dataset and exploring more sophisticated model architectures to further improve detection accuracy.

1 January 2013 in Information Technology and Management Science
Verified
Journal Article
Open access
PDF file
ABAndrejs Bondarenko
Andrejs Bondarenko
ABArkady Borisov
Arkady Borisov

6 September 2024
Verified
Conference Paper
Open access
PDF file
JMJulija Mironova
Julija Mironova
VRViktoria Riiascshenko
Viktoria Riiascshenko
ABAndrejs Bondarenko
Andrejs Bondarenko
RKRemigijus Kinderis
Remigijus Kinderis
OVOlga Verdenhofa
Olga Verdenhofa
Since generative tools of Artificial Intelligence appeared in education, ongoing discussion arose. Still, higher education institutions argue if generative tools can be used, and if yes, what exactly can be accepted. The purpose of this study is to investigate for what exactly students use the generative tool Chat GPT in their studies, as well as to determine if there is a statistically significant difference between students representing different fields of study in terms of usage of Chat GPT in general, as well as in evaluation of the knowledge. The objectives of the study are to research recent scientific findings, as well as to analyze the results of the survey created by authors, which was distributed in Latvia, Lithuania, Ukraine, Bulgaria and Uzbekistan. Methods of the study are analysis of the recent findings and statistical analysis of the survey. To test hypotheses, the authors employed the Kruscal-Wallis non-parametric test for both hypotheses, where authors tested if there are statistically significant differences between answers of students from different education fields. The final results highlight the use of Chat GPT by students in higher education.

30 August 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
Vilen JumutcVilen Jumutc
Vilen Jumutc
ASArtjoms Suponenkovs
Artjoms Suponenkovs
ABAndrejs Bondarenko
Andrejs Bondarenko
DBDmitrijs Bliznuks
Dmitrijs Bliznuks
ALAlexey Lihachev
Alexey Lihachev
The Colony-Forming Unit (CFU) counting problem remains a complex issue without a universal solution in biomedical and food safety domains. A multitude of sophisticated heuristics and segmentation-driven approaches have been proposed by numerous researchers. Among those, U-Net is the most frequently cited and popular Deep Learning method. The latter approach provides a segmentation output map and requires an additional counting procedure which accounts for unique segmented regions and detected microbial colonies. However, because of pixel-based targets it tends to generate irrelevant artifacts or errant pixels, leading to inaccurate and mixed post-processing results. In response to these challenges, we propose a novel hybrid counting approach, incorporating a multi-loss U-Net reformulation and a post-processing Petri dish localization algorithm. First of all, our unique innovation lies in the multi-loss U-Net reformulation. We introduce an additional loss term at the bottleneck U-Net layer, focusing on delivering an auxiliary signal indicating where to look for distinct CFUs. Second, our novel localization algorithm accurately incorporates an agar plate and its bezel into the CFU counting routines. Finally, our proposition is further enhanced by the integration of a fully automated solution. This comprises a specially designed uniform Petri dish illumination system and a counting web application. The latter application is capable of directly receiving images from the camera, which are subsequently processed, and the segmentation results are sent back to the user. This feature provides an opportunity to correct the CFU counts, offering a feedback loop that contributes to the continued development of the Deep Learning model. Through extensive experimentation, we have found that all probed multi-loss U-Net architectures incorporated in our hybrid approach consistently outperform their single-loss counterparts which utilize exclusively the combination of Tversky and Cross-Entropy training losses at the output U-Net layer. We report further significant improvements by the means of our novel localization algorithm. This reaffirms the effectiveness of our proposed hybrid solution in addressing contemporary challenges of the precise in-vitro CFU counting.