{"title":"Spatio-spectral independent component analysis for fetal ECG extraction from two-channel maternal abdominal signals","authors":"Marian P. Kotas , Anwar M. AlShrouf","doi":"10.1016/j.bbe.2024.02.002","DOIUrl":"https://doi.org/10.1016/j.bbe.2024.02.002","url":null,"abstract":"<div><p>Independent component analysis (ICA) is widely used to separate maternal and fetal electrocardiograms. However, it has become less effective due to the efforts to reduce the number of recording electrodes. To address this issue, we propose an extension of ICA that can extract the fetal electrocardiogram from only two maternal abdominal electric signals. We solve this problem by increasing the dimension of the observed signals using the method of delays, followed by spatio-spectral filtering to separate the source signals. By iteratively applying this approach, we can extract signals that are not separable using the original observations alone. These signals are then clustered to create signal subspaces corresponding to different sources, allowing for a rough reconstruction of signal components produced by these sources. This initial decomposition can then be refined by using the reconstructed components as new observations, extending the original ones, and applying ICA to this extended signal representation.</p><p>Applied to two-channel maternal abdominal signals, the proposed method was able to extract 3 source signals (two maternal and one fetal), resulting in the achievement of the goal of over-complete blind source separation (BSS). Furthermore, the method enabled the successful detection of fetal QRS (fQRS) complexes in experiments on two datasets of real-world maternal abdominal signals. For the ADFECGDB dataset, the method reached the sensitivity, positive predictivity, and F1 score of 100%, 99.97%, and 99.98%, respectively, outperforming all reference methods. For the PREGNANCY dataset, the corresponding values were 98.95%, 98.92%, and 98.93%, second only to one reference method.</p></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"44 1","pages":"Pages 247-263"},"PeriodicalIF":6.4,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139943001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yunfan Zhu , Fangjie Zheng , Yanji Gong , Deqiang Yin , Yang Liu
{"title":"Biomechanical behavior of customized splint for the patient with temporomandibular disorders: A three-dimensional finite element analysis","authors":"Yunfan Zhu , Fangjie Zheng , Yanji Gong , Deqiang Yin , Yang Liu","doi":"10.1016/j.bbe.2023.12.007","DOIUrl":"https://doi.org/10.1016/j.bbe.2023.12.007","url":null,"abstract":"<div><p>The mechanical overloading of temporomandibular joint (TMJ) is generally linked to temporomandibular disorders (TMD). However, in patients with a typical combination of maxillofacial morphology and occlusal features, the reduction of joint load and treatment with general occlusal splints are often ineffective. This study investigates the biomechanical behavior of the stomatognathic system in a TMD patient with personalized splints by finite element analysis. The therapeutic position, determined based on the intercuspal position, served as the basis for designing personalized customized splints. The design of occlusal contact and splint structure was evaluated in terms of their impact on the maximum stress level in the TMJ and the biting forces on the dentition. The relationship between joint stress and biting force was further examined during treatment with different customized splints. In preoperative case, there was a significant increase in stress level and stress concentration in the medial to posterior band of the articular disc. However, in all customized splint cases, the highest stress area shifted to the intermediate zone and exhibited a decrease. Notably, the bi-splints demonstrated superior ability in relieving overloading and balancing the occlusal force on both sides of the dentition, as verified by clinical treatment. The predictable simulated results offer valuable interactive information regarding TMJ overload, aiding doctors in making better-informed clinical decisions in future.</p></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"44 1","pages":"Pages 83-94"},"PeriodicalIF":6.4,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139109009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aurora Espinoza-Valdez , Griselda Quiroz-Compean , Andrés A. González-Garrido , Ricardo A. Salido-Ruiz , Luis Mercado
{"title":"Spatial characterization of functional neural activity during lower limb motion through functional connectivity","authors":"Aurora Espinoza-Valdez , Griselda Quiroz-Compean , Andrés A. González-Garrido , Ricardo A. Salido-Ruiz , Luis Mercado","doi":"10.1016/j.bbe.2024.01.003","DOIUrl":"10.1016/j.bbe.2024.01.003","url":null,"abstract":"<div><p><span>Analyzing electroencephalographic signals (EEG) could provide valuable information about functional neural activity (FNA) during human motion. The hypothesis of this work is twofold: spatial patterns emerge in EEG signals from functional connectivity (FC) analysis during lower limb movements, and the spatial patterns are mosto robust in some frequency bands than in others. Accordingly, a set of human subjects without neuromotor pathologies participated in an experimental trial where EEG signals were recorded during lower limb movements. The FC was studied with coherence analysis (in </span><span><math><mi>δ</mi></math></span>, <span><math><mi>θ</mi></math></span>, and <span><math><mi>α</mi></math></span>) and graph theory was proposed to study the characteristics of spatial dynamics by means a set of metrics (degree, maximum connection, and closeness centrality) and two distances (Hamming distance and Jaccard). Finally, a statistical study of the metrics by frequency band was performed to analyze the significant differences between the phases of each stage and movement, considering the proposed metrics. The results of the study indicated that the frequency bands that showed greater statistical significance in the analysis were <span><math><mi>δ</mi></math></span>, <span><math><mi>θ</mi></math></span>, and <span><math><mi>α</mi></math></span> and that the major differences in graph dynamics were shown in degree, maximum connection, and closeness centrality in <span><math><mi>α</mi></math></span><span> band. Present findings portray leading underlying neural networks, implying that discernible spatial patterns exist in FNA during lower limb movements, and such patterns can be characterized with the proposed methodology.</span></p></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"44 1","pages":"Pages 183-196"},"PeriodicalIF":6.4,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139646715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kamil Liżewski , Slawomir Tomczewski , Dawid Borycki , Piotr Węgrzyn , Maciej Wojtkowski
{"title":"Imaging the retinal and choroidal vasculature using Spatio-Temporal Optical Coherence Tomography (STOC-T)","authors":"Kamil Liżewski , Slawomir Tomczewski , Dawid Borycki , Piotr Węgrzyn , Maciej Wojtkowski","doi":"10.1016/j.bbe.2023.12.002","DOIUrl":"https://doi.org/10.1016/j.bbe.2023.12.002","url":null,"abstract":"<div><p>Spatio-Temporal Optical Coherence Tomography (STOC-T) is a novel imaging technique using light with controlled spatial and temporal coherence. Retinal images obtained using the STOC-T system maintain high resolution in all three dimensions, on a sample of about 700 μm, without the need for mechanical scanning. In the present work, we use known data processing algorithms for optical coherence tomography angiography (OCTA) and modify them to improve the rendering of the vasculature in the human retina at different depths by introducing the angio STOC-T method. The algorithms are primarily sensitive to the strong signal phase variance corresponding to the appearance of a wide Doppler band in STOC-T signals obtained for millisecond exposure times. After using STOC-T angiography, we can render high contrast images of the choroid.</p></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"44 1","pages":"Pages 95-104"},"PeriodicalIF":6.4,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0208521623000748/pdfft?md5=fec78bc6e6a1b5ac576698ca31dc7f53&pid=1-s2.0-S0208521623000748-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139398925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xin Wen , Xing Guo , Shuihua Wang , Zhihai Lu , Yudong Zhang
{"title":"Breast cancer diagnosis: A systematic review","authors":"Xin Wen , Xing Guo , Shuihua Wang , Zhihai Lu , Yudong Zhang","doi":"10.1016/j.bbe.2024.01.002","DOIUrl":"https://doi.org/10.1016/j.bbe.2024.01.002","url":null,"abstract":"<div><p>The second-leading cause of death for women is breast cancer. Consequently, a precise early diagnosis is essential. With the rapid development of artificial intelligence, computer-aided diagnosis can efficiently assist radiologists in diagnosing breast problems. Mammography images, breast thermal images, and breast ultrasound images are the three ways to diagnose breast cancer. The paper will discuss some recent developments in machine learning and deep learning in three different breast cancer diagnosis methods. The three components of conventional machine learning methods are image preprocessing, segmentation, feature extraction, and image classification. Deep learning includes convolutional neural networks, transfer learning, and other methods. Additionally, the benefits and drawbacks of different methods are thoroughly contrasted. Finally, we also provide a summary of the challenges and potential futures for breast cancer diagnosis.</p></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"44 1","pages":"Pages 119-148"},"PeriodicalIF":6.4,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0208521624000020/pdfft?md5=91d91592ef5090eeae962ba35d05faee&pid=1-s2.0-S0208521624000020-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139488032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Application of context-dependent interpretation of biosignals recognition to control a bionic multifunctional hand prosthesis","authors":"Pawel Trajdos, Marek Kurzynski","doi":"10.1016/j.bbe.2024.01.001","DOIUrl":"https://doi.org/10.1016/j.bbe.2024.01.001","url":null,"abstract":"<div><p>The paper presents an original method for controlling a surface-electromyography-driven (sEMG) prosthesis. A context-dependent recognition system is proposed in which the same class of sEMG signals may have a different interpretation, depending on the context. This allowed the repertoire of performed movements to be increased. The proposed structure of the context-dependent recognition system includes unambiguously defined decision sequences covering the overall action of the prosthesis, i.e. the so-called boxes. Because the boxes are mutually isolated environments, each box has its own interpretation of the recognition result, as well as a separate local-recognition-task-focused classifier.</p><p><span>Due to the freedom to assign contextual meanings to classes of biosignals, the construction procedure of the classifier can be optimised in terms of the local classification quality in a given box or the classification quality of the entire system. In the paper, two optimisation problems are formulated, differing in the adopted constraints on optimisation variables, with the methods of solving the problems based on an </span>exhaustive search<span> and an evolutionary algorithm, being developed.</span></p><p>Experimental studies were conducted using signals from 1 able-bodied person with simulation of amputation and 10 volunteers with transradial amputations. The study compared the classical recognition system and the context-dependent system for various classifier models. An unusual testing strategy was adopted in the research, taking into account the specificity of the considered recognition task, with two original quality measures resulting from this scheme then being applied. The results obtained confirm the hypothesis that the application of the context-dependent classifier led to an improvement in classification quality.</p></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"44 1","pages":"Pages 161-182"},"PeriodicalIF":6.4,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139549143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the prediction of the effect of bi-ventricular assistance after cardiac explantation on the vascular flow physiology: A numerical study","authors":"Louis Marcel , Mathieu Specklin , Smaine Kouidri , Mickael Lescroart , Jean-Louis Hébert","doi":"10.1016/j.bbe.2023.12.005","DOIUrl":"https://doi.org/10.1016/j.bbe.2023.12.005","url":null,"abstract":"<div><p><span><span>Heart failure is a chronic and progressive condition characterized by the heart’s inability to pump sufficient blood to meet the body’s metabolic demands. It is a significant public health concern worldwide, associated with high morbidity, mortality, and healthcare costs. For advanced heart failure cases not responding to medical therapy, heart transplantation or mechanical circulatory<span> support with ventricular assist devices (VADs) can be considered. In the specific case of bi-ventricular heart failure a replacement of both ventricles is required. In this context a Total Artificial Heart (TAH) may be proposed as a bridge to transplant solution. Additionally, bi-ventricular assist devices (BiVADs) are available to support both ventricles simultaneously. However Bi-ventricular heart failure management is difficult with poor outcomes. New surgical procedures appear to propose solutions after both ventricle failure. One of these intervention uses two continuous-flow VADs as a total artificial heart after cardiac </span></span>explantation due to myocardial sarcoma. Unfortunately, this procedure makes patient management very difficult as pulmonary pressures and flow rate are no longer measurable after the surgical procedure. The setting of both pumps is hence a complex task for patient management. This article aims at helping clinicians on patient management undergoing double assistance after cardiac explantation by predicting the different outcomes on the vascular grid for all the possible </span>rotational speed combination using a lumped model. Results provide a range of both pump operating conditions suitable for delivering a physiologically adapted flow to the vascular grid when combined with hypotensive treatments.</p></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"44 1","pages":"Pages 105-118"},"PeriodicalIF":6.4,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139433595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dawid Borycki , Egidijus Auksorius , Piotr Węgrzyn , Kamil Liżewski , Sławomir Tomczewski , Ieva Žičkienė , Karolis Adomavičius , Karol Karnowski , Maciej Wojtkowski
{"title":"Multiwavelength laser doppler holography (MLDH) in spatiotemporal optical coherence tomography (STOC-T)","authors":"Dawid Borycki , Egidijus Auksorius , Piotr Węgrzyn , Kamil Liżewski , Sławomir Tomczewski , Ieva Žičkienė , Karolis Adomavičius , Karol Karnowski , Maciej Wojtkowski","doi":"10.1016/j.bbe.2024.03.002","DOIUrl":"https://doi.org/10.1016/j.bbe.2024.03.002","url":null,"abstract":"<div><p>Spatiotemporal optical coherence tomography (STOC-T) is the novel modality for high-speed, crosstalk- and aberration-free volumetric imaging of biological tissue <em>in vivo</em>. STOC-T extends the Fourier-Domain holographic Optical Coherence Tomography by the spatial phase modulation that enables the reduction of spatial coherence of the tunable laser. By reducing the spatial coherence of the laser, we suppress coherent noise, and, consequently, improve the imaging depth. Furthermore, we remove geometrical aberrations computationally in postprocessing. We recently demonstrated high-speed, high-resolution STOC-T of human retinal imaging <em>in vivo</em>. Here, we show that the dataset produced by STOC-T can be processed differently to reveal blood flow in the human retina <em>in vivo</em>. To render the blood flow, we first pre-process STOC-T holographic data to access the approximated information about the Doppler-shifted optical field backscattered from the sample. Then, we analyze it using methods from the laser Doppler flowmetry, namely, by analyzing the Doppler broadening caused by moving light scatterers (red blood cells). However, contrary to conventional approaches, we use multiple illumination wavelengths. This enables us to render the structural volumetric and blood flow images from the same dataset concurrently. Our method, denoted as multiwavelength laser Doppler holography (MLDH), links laser Doppler flowmetry with multiwavelength holographic detection to enable noninvasive visualization and possible blood flow quantification at different human retina layers at high speeds and high transverse resolution <em>in vivo</em>.</p></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"44 1","pages":"Pages 264-275"},"PeriodicalIF":6.4,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0208521624000111/pdfft?md5=fbd875c488dc4651bec90fa168ae6951&pid=1-s2.0-S0208521624000111-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140113616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multi-scale local-global transformer with contrastive learning for biomarkers segmentation in retinal OCT images","authors":"Xiaoming Liu , Yuanzhe Ding , Ying Zhang , Jinshan Tang","doi":"10.1016/j.bbe.2024.02.001","DOIUrl":"https://doi.org/10.1016/j.bbe.2024.02.001","url":null,"abstract":"<div><p>Quantitative analysis of biomarkers in Optical Coherence Tomography (OCT) images plays an import role in the diagnosis and treatment of retinal diseases. However, biomarker segmentation in retinal OCT images is very hard due to the large variations in size and shape of retinal biomarkers, blurred boundaries, low contrast, and speckle interference. We proposed a novel <strong>M</strong>ulti-<strong>s</strong>cale <strong>L</strong>ocal-<strong>G</strong>lobal <strong>T</strong>ransformer network (MsLGT-Net) for biomarker segmentation in retinal OCT images. The network combines the proposed <strong>M</strong>ulti-scale <strong>F</strong>usion <strong>A</strong>ttention (MFA) module, <strong>L</strong>ocal-<strong>G</strong>lobal <strong>T</strong>ransformer (LGT) module, and <strong>C</strong>ontrastive <strong>L</strong>earning <strong>E</strong>nhancement (CLE) module to tackle the challenges of biomarker segmentation. Specifically, the proposed MFA module aims to enhance the network’s ability to learn multi-scale features of retinal biomarkers by effectively combining the local detail information and contextual semantic information of biomarkers at different scales, and improve the representation ability for different classes of biomarkers. The LGT module is designed to learn local and global information adaptively from multi-scale fused features to address the challenge of small biomarker segmentation. In addition, to distinguish features between different types of retinal biomarkers, we propose the CLE module to enhance the feature representation of different biomarkers. Our proposed method is validated on one public dataset and one local dataset. The experimental results show that the proposed method is more effective than other state-of-the-art methods.</p></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"44 1","pages":"Pages 231-246"},"PeriodicalIF":6.4,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139743583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aleksandra Kuls-Oszmaniec , Michał Kacprzak , Magdalena Morawiec , Piotr Sawosz , Urszula Fiszer , Marta Leńska-Mieciek
{"title":"Time-resolved near-infrared spectroscopy in monitoring acute ischemic stroke patients – Case study","authors":"Aleksandra Kuls-Oszmaniec , Michał Kacprzak , Magdalena Morawiec , Piotr Sawosz , Urszula Fiszer , Marta Leńska-Mieciek","doi":"10.1016/j.bbe.2023.12.006","DOIUrl":"https://doi.org/10.1016/j.bbe.2023.12.006","url":null,"abstract":"<div><p>Stroke is a leading cause of disability and death worldwide, with acute ischemic stroke<span> (AIS) accounting for the majority of cases. Early and accurate diagnosis of AIS is crucial for improving patient outcomes. Non-invasive monitoring techniques, such as time domain near-infrared spectroscopy (tdNIRS), have shown potential for real-time monitoring of AIS patients at the bedside. However, there is a need for further research to evaluate the effectiveness of tdNIRS in the acute phase of stroke. In this study, we present the results of a case report using tdNIRS to monitor AIS patients without any additional stimulation. The tdNIRS technique allows for non-invasively assessing cerebral oxygenation in absolute units, enabling accurate measurement of changes in oxygenated and deoxygenated hemoglobin concentrations in the brain. Our aim was to determine the feasibility of tdNIRS in monitoring AIS patients.</span></p></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"44 1","pages":"Pages 149-160"},"PeriodicalIF":6.4,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139503513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}