Biocybernetics and Biomedical Engineering最新文献

{"title":"A novel class of rank tests for high-dimensional data with an application to Alzheimer’s disease","authors":"Jan Kalina ,&nbsp;Jaromir Kukal ,&nbsp;Oldrich Vysata","doi":"10.1016/j.bbe.2025.10.005","DOIUrl":"10.1016/j.bbe.2025.10.005","url":null,"abstract":"<div><div>Electroencephalography (EEG) signals are widely used in neuroscience research and biomedical applications, particularly for comparative analyses between two cohorts: patients and control subjects. In EEG research, multivariate two-sample tests remain underused, while multiple comparison procedures are often misapplied as a substitute, leading to inadequate error control. Moreover, existing rank-based tests rely solely on Euclidean distances and lack robustness to outliers. The objective of this work is to develop and evaluate a new class of rank-based tests for high-dimensional data that employ robust Mahalanobis interpoint distances, and to demonstrate their practical value in the analysis of EEG signals. This class includes a version based on the MRWCD (minimum regularized weighted covariance determinant) estimator, which enhances the robustness of the Mahalanobis distances by mitigating the influence of outliers.</div><div>To illustrate the effectiveness of these tests, EEG data consisting of 1216 variables from 28 patients with Alzheimer’s disease and 146 healthy control individuals were analyzed. The results of multivariate tests reveal significant findings, which are also explored in the context of individual EEG channels and frequencies. Among the approaches tested, rank-based tests using the newly proposed interpoint distances, particularly in combination with the Cucconi test statistic, yield the strongest results. For the comparison between patients and controls, a <em>p</em>-value of 0.004 was obtained, which is below the significance level <span><math><mrow><mi>α</mi><mo>=</mo><mn>0.05</mn></mrow></math></span>, indicating a statistically significant difference.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 4","pages":"Pages 707-717"},"PeriodicalIF":6.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145617670","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":"Reevaluating performance in c-VEP BCIs: The impact of calibration time","authors":"Víctor Martínez-Cagigal ,&nbsp;Eduardo Santamaría-Vázquez ,&nbsp;Sergio Pérez-Velasco ,&nbsp;Ana Martín-Fernández ,&nbsp;Roberto Hornero","doi":"10.1016/j.bbe.2025.10.006","DOIUrl":"10.1016/j.bbe.2025.10.006","url":null,"abstract":"<div><div>Code-modulated visual evoked potentials (c-VEP) have demonstrated high performance in non-invasive brain-computer interfaces (BCIs). Recently, research has begun to consider practical aspects such as visual comfort, where non-binary sequences and variations in the spatial frequency of stimuli play significant roles. However, calibration requirements remain underexplored in performance comparisons. This study aims to analyze a multi-variable tradeoff crucial to the practical application of c-VEP-based BCIs: decoding accuracy, decoding speed, and calibration time. Visual comfort is retrospectively evaluated using two pre-recorded datasets. Models were trained with increasing calibration cycles and tested across varying decoding times, depicting learning and decoding curves. The datasets comprised 32 healthy subjects, and featured different stimulus paradigms: plain non-binary stimuli and checkerboard-like binary stimuli with spatial frequency variations. Results showed that all conditions achieved over 97 % grand-averaged accuracy with sufficient calibration. However, a clear tradeoff emerged between calibration duration and performance. Achieving 95 % average accuracy within a 2 s decoding window required mean calibration durations of 28.7 ± 19.0 s for binary stimuli, or 148.7 ± 72.3 s for non-binary stimuli. The binary checkerboard-based condition with a spatial frequency of 1.2 c/º (C016) proved to be particularly effective, achieving over 95 % accuracy within 2 s decoding window using only 7.3 s of calibration, and reporting a significant improvement in visual comfort. A minimum calibration time of 1 min was considered essential to adequately estimate the brain response, critical in template-matching paradigms. In conclusion, achieving optimal c-VEP performance requires balancing calibration duration, decoding speed and accuracy, and visual comfort.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 4","pages":"Pages 685-696"},"PeriodicalIF":6.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145519677","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":"TRI-based heart rate variability parameterisation: advancing autonomic dysfunction assessment in diabetes and aging—A cross-sectional observational study","authors":"Shanglin Yang ,&nbsp;Yuyang Lin ,&nbsp;Xuwei Liao ,&nbsp;Jianjung Chen ,&nbsp;Hsientsai Wu","doi":"10.1016/j.bbe.2025.08.006","DOIUrl":"10.1016/j.bbe.2025.08.006","url":null,"abstract":"<div><div>This cross-sectional observational study introduces the T-R interval (TRI), a novel electrocardiographic parameter designed to improve heart rate variability (HRV) assessment in ageing and diabetic populations. Defined as the R-R interval (RRI) minus the heart rate-corrected RT interval (RTc), TRI incorporates both depolarisation and repolarisation phases of the cardiac cycle, thereby offering deeper insights into autonomic function. A total of 126 participants, including 58 individuals with type 2 diabetes mellitus and 68 healthy controls, were assessed using conventional HRV indices. These included the low-to-high frequency power ratio (LHR), the short-to-long variability ratio (SSR), and the baroreflex entropy index (BEI), all of which were calculated from both RRI and TRI data. TRI-based indices demonstrated superior sensitivity in detecting autonomic dysfunction. Significant group differences were observed for TRI-derived MSE_LS (mean difference = 0.205, 95 % CI: 0.093–0.317, <em>p</em> = 0.036), SSR (mean difference =  − 0.083, 95 % CI: −0.136–−0.029, <em>p</em> = 0.051), and BEI (mean difference = 0.205, 95 % CI: 0.093–0.318, <em>p</em> = 0.002), while their RRI-based equivalents did not reach statistical significance. ROC curve analysis showed improvements in the area under the curve (AUC) when TRI was used as the input parameter, with gains of 5.9 % for MSE_LS, 10.6 %for SSR, and 6.1 % for BEI. Logistic regression further identified TRI-based BEI as a protective factor against new-onset T2DM (OR = 0.058; 95 % CI: 0.009–0.378; <em>p</em> = 0.003). These findings suggest that TRI improves the diagnostic performance of HRV analysis and may support earlier detection of autonomic dysfunction, especially in clinical and wearable monitoring settings.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 4","pages":"Pages 581-592"},"PeriodicalIF":6.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144914029","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":"A morphometric lung model for evaluating lung aeration at birth","authors":"Chiara Veneroni ,&nbsp;Enrico Conca ,&nbsp;Davide Bizzotto ,&nbsp;Kenneth Lutchen ,&nbsp;Alberto Tosi ,&nbsp;Raffaele L. Dellacà","doi":"10.1016/j.bbe.2025.11.004","DOIUrl":"10.1016/j.bbe.2025.11.004","url":null,"abstract":"<div><h3>Background</h3><div>Lung aeration must rapidly develop at birth, but how to promote it without injuring the fragile lung is still unknown. Mathematical models simulating lung mechanics during this transition may help understand the underlying physiological mechanisms and design protective ventilation strategies. This study develops a morphologically-coherent computational lung model incorporating changing physical conditions during the transition from liquid-filled to gas-filled lungs.</div></div><div><h3>Methods</h3><div>We adapted a 3-D morphological model of the adult airway tree adjusting airway dimensions, lung volume, and lung tissue mechanical properties. Changes in resistance, inertia, and compliance during aeration were modeled by considering the differing properties of fetal fluid versus air. The capillary pressure at the liquid–air interface was computed using Laplace equation. Terminal airway diameters increased with lung volume due to airway-parenchymal interdependence. An integrated circuit simulator solved the entire network in the time domain.</div></div><div><h3>Results</h3><div>The air volume entering the model at different applied pressures increased exponentially with time. With 30 cmH₂O applied, lung volume reached total capacity after 15 s, matching lung aeration dynamics observed in animal models and human infants. In contrast, after the same time, at 15 cmH₂O, lung volume was slightly above functional residual capacity, and at 10 cmH₂O, it remained below.</div></div><div><h3>Conclusions</h3><div>The proposed in-silico newborn lung model simulates lung aeration at birth, allowing observation of the airway emptying sequence and the heterogeneity of aeration at each time point. Integrating this model with comprehensive acinar models may aid in defining protective resuscitation ventilation strategies for recruiting the lung minimizing risk of injuries.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 4","pages":"Pages 718-725"},"PeriodicalIF":6.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145617672","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":"Dual-peak cyclic loading for evaluation of lower-limb prostheses","authors":"Zhaokun Zhang ,&nbsp;Wangrui Xu ,&nbsp;Hanyu Gan ,&nbsp;Chunlei K. Song ,&nbsp;Albert J. Shih","doi":"10.1016/j.bbe.2025.10.004","DOIUrl":"10.1016/j.bbe.2025.10.004","url":null,"abstract":"<div><div>Lower-limb prosthesis (LLP) is critical for the mobility and quality of life of amputees. Ensuring the reliability and durability of LLPs is essential to users’ safety, comfort, and mobility. While the current standard (ISO 10328) for the mechanical test of LLPs has served as a foundation, the sinusoidal cyclic loading method used for fatigue testing does not replicate the actual loading conditions on LLPs during a human walking gait. In normal walking, LLPs are subjected to a dual-peak loading condition with two distinct force peaks at the heel-strike and toe-off phases. Such a cyclic and dual-peak dynamic loading pattern on LLP is essential to test the durability of the LLP effectively and reliably. In this study, two simple and effective dual-peak cyclic loading test apparatuses are designed and built to evaluate the durability and functionality of LLPs. Two loading plates are used to contact the heel and toe of the prosthetic foot to simulate the dual-peak heel-strike and toe-off loadings between the foot and the ground. This dual-peak loading on the LLP is controlled and replicated by adjusting the positions of two loading plates and the actuator stroke to change the contact forces. Experimental results show that the proposed testing apparatuses and procedures can emulate the dual-peak axial loading of the LLP during normal walking gait, providing a more accurate testing method of the dynamic loading condition on LLPs than the current ISO standard.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 4","pages":"Pages 642-654"},"PeriodicalIF":6.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145416927","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":"Viscoelastic modeling of optic nerve head biomechanics: Effects of intraocular and cerebrospinal fluid pressure","authors":"Alireza Karimi ,&nbsp;Reza Razaghi ,&nbsp;Seyed Mohammadali Rahmati ,&nbsp;J. Crawford Downs","doi":"10.1016/j.bbe.2025.05.008","DOIUrl":"10.1016/j.bbe.2025.05.008","url":null,"abstract":"<div><div>Although the optic nerve head (ONH) has demonstrated a significant viscoelastic response to changes in intraocular pressure (IOP), existing computational models of ONH biomechanics have yet to fully account for these viscoelastic properties. In this study, we introduce and evaluate a mesh-free beam-in-solid coupling algorithm to model the complex viscoelastic behavior of anisotropic collagen fibers within a viscoelastic scleral matrix. We also incorporated viscoelastic formulations for the retina, lamina cribrosa, and optic nerve to provide a more comprehensive understanding of ONH tissue mechanics. We compared the biomechanics of the ONH resulting from hyperelastic and viscoelastic scleral material formulations using an eye-specific finite element model of the posterior human eye. This model integrates the detailed 3D microstructure of the load-bearing lamina cribrosa, including interspersed laminar neural tissues, as well as the heterogeneous, anisotropic behavior of the collagenous sclera and pia. The viscoelastic material properties were validated against published experimental tensile tests of human scleral and retinal tissue samples. Simulations of ONH biomechanical responses were conducted by applying changes in IOP and cerebrospinal fluid pressure (CSFP) typical of body position transitions, such as moving from sitting to supine, over a 250 ms period. In both simulations, the ONH tissues exhibited greater stresses and strains in the supine position compared to sitting, as anticipated. The laminar surface showed posterior deformation (+6 µm) during the transition from sitting to supine when using the hyperelastic material model, whereas it deformed anteriorly (−5.7 µm) with the viscoelastic model. Furthermore, the radial scleral canal expansion at the anterior laminar insertion was significantly smaller in the viscoelastic formulation (9 µm) compared to the hyperelastic formulation (19.8 µm). All results aligned with experimental observations. While the stresses, strains, and deformations remained within physiological ranges for both models, there were substantial differences between the two formulations, particularly in terms of deformation. Improving the accuracy of material formulations in ONH models is expected to enhance our understanding of ONH biomechanics. However, further experimental validation is needed to confirm these results and strengthen their applicability.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 3","pages":"Pages 357-379"},"PeriodicalIF":5.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144090192","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":"Hemodynamic simulation for plantar arteries by anatomical structure based mathematical model","authors":"Lei Sun ,&nbsp;Xiang Geng ,&nbsp;Yichong Wang ,&nbsp;Daoyuan Wang ,&nbsp;Xin Ma ,&nbsp;Gangmin Ning","doi":"10.1016/j.bbe.2025.05.006","DOIUrl":"10.1016/j.bbe.2025.05.006","url":null,"abstract":"<div><div>Diabetic foot is a kind of common complications in diabetic patients, manifesting as ischemic lesions in plantar tissue. The plantar tissue ischemia can be estimated by the perfusion of plantar blood flow. Currently, it lacks effective methods to monitor and assess plantar blood flow perfusion in practice and detailed information is not available. This study intends to address this problem from the view of mathematical modelling. It aims to provide quantitative approach to investigate the risk of ischemia in diabetic foot by simulating the hemodynamic status along the plantar vascular network. A simplified topological structure map of the main plantar arteries was established considering the anatomical structure and physical data of each vessel. Aided by bond graph technology, a Poiseuille’s law based hemodynamic model of the plantar vessels was constructed. The model simulated the blood flow distribution in the feet of healthy individuals and diabetic patients. Compared with healthy individuals, diabetic patients show increased plantar blood pressure and decreased blood supply. The reduction in blood flow on the lateral side of the foot is greater than on the medial side in diabetic patients. The study marks the first application of vascular modeling in the plantar region, providing a quantitative method for investigating foot hemodynamics in diabetic patients and offering new potential for assessing the progression of diabetic foot and the risk of tissue ulceration.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 3","pages":"Pages 390-398"},"PeriodicalIF":5.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144131213","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":"Can cerebral autoregulation be monitored with non-linear correlation indices? A proof-of-concept study","authors":"Karol Sawicki ,&nbsp;Arkadiusz Syta ,&nbsp;Pawel Dzienis ,&nbsp;Lukasz Tymiński ,&nbsp;Bartlomiej Ambrożkiewicz ,&nbsp;Andrzej Koszewnik ,&nbsp;Magdalena Maria Sawicka ,&nbsp;Tomasz Łysoń ,&nbsp;Zofia Czosnyka ,&nbsp;Marek Czosnyka","doi":"10.1016/j.bbe.2025.07.005","DOIUrl":"10.1016/j.bbe.2025.07.005","url":null,"abstract":"<div><h3>Objective</h3><div>Cerebral autoregulation (CA) is the mechanism by which cerebral vessels self-regulate blood flow to maintain adequate brain perfusion. Although CA monitoring is recommended in neurocritical care as a means to improve therapy, there is currently no consensus on the most effective computational technique. The aim of this study was to evaluate the feasibility of measuring CA using recurrence quantification analysis (RQA)—a non-linear method for analysing complex systems—as an alternative to traditional, linear correlation-based indices.</div></div><div><h3>Methods</h3><div>A retrospective analysis was conducted on a database of head-injured patients treated in a neurocritical care unit who developed spontaneous intracranial pressure (ICP) elevations known as plateau waves. Signals from arterial blood pressure, ICP, and cerebral blood flow velocity were segmented into stable phases of elevated ICP (associated with CA deterioration) and the preceding baseline. Non-linear RQA correlations were calculated for both periods, and the results were statistically compared. For reference, well-established linear CA indices were assessed in the same manner.</div></div><div><h3>Results</h3><div>The non-linear correlations followed a similar pattern to the linear CA indices and successfully differentiated the plateau wave phase with a comparable, high level of statistical significance (p &lt; 0.0001), while demonstrating higher values and reduced data dispersion.</div></div><div><h3>Conclusion</h3><div>Non-linear RQA correlation is feasible<!--> <!-->for CA assessment.<!--> <!-->To the best of the authors’ knowledge, this is the first evaluation of RQA feasibility in CA research. In the pursuit of a reliable<!--> <!-->index suitable for widespread implementation in neurocritical care, a non-linear approach may offer a promising alternative to traditional linear correlation-based indices.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 3","pages":"Pages 485-495"},"PeriodicalIF":5.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144633201","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":"Lumbar intervertebral disc biomechanics: Geometry and collagen fiber orientation configurations effects","authors":"Zhongwei Sun ,&nbsp;Jiabao Pan ,&nbsp;Weishi Liang ,&nbsp;Changwen Mi ,&nbsp;Peng Yin","doi":"10.1016/j.bbe.2025.07.003","DOIUrl":"10.1016/j.bbe.2025.07.003","url":null,"abstract":"<div><div>This study proposes a probabilistic biphasic-swelling parameterized finite element framework, with the aim of which is to systematically evaluate the impact of lumbar intervertebral disc (L-IVD) geometry and annulus fibrosus collagen fiber configuration on multi-axial biomechanical behavior. Thirty anatomical L-IVD geometric sets were sampled via Latin hypercube sampling of clinical anatomical variations. Three annulus fibrosus layer-wise fiber configurations were implemented: Constant <span><math><msup><mn>30</mn><mo>∘</mo></msup></math></span>, Circumferential variation (<span><math><mrow><msup><mn>25</mn><mo>∘</mo></msup><mo>−</mo><mo>−</mo><msup><mn>45</mn><mo>∘</mo></msup></mrow></math></span>), and Circumferential-radial variation (<span><math><mrow><msup><mn>23</mn><mo>∘</mo></msup><mo>−</mo><mo>−</mo><msup><mn>50</mn><mo>∘</mo></msup></mrow></math></span>). Consequently, the construction of three groups, comprising a total of ninety biphasic L-IVD finite element models, was undertaken. Five loading protocols were then simulated to reveal the critical dependencies of L-IVD biomechanical behavior. A statistical comparative analysis was performed to evaluate the influence of disc geometries and orientation strategies. The findings demonstrated that fiber orientation configuration exerts a substantial influence on swelling responses, compression stiffness, and flexion stiffness (<span><math><mrow><mi>p</mi><mo>&lt;</mo><mo>.</mo><mn>050</mn></mrow></math></span>). Disc height exhibited strong inverse correlations with intradiscal pressure (<span><math><mrow><mi>r</mi><mo>&lt;</mo><mo>−</mo><mn>0.80</mn></mrow></math></span>, <span><math><mrow><mi>p</mi><mo>&lt;</mo><mo>.</mo><mn>001</mn></mrow></math></span>) and compression stiffness (<span><math><mrow><mi>r</mi><mo>&lt;</mo><mo>−</mo><mn>0.85</mn></mrow></math></span>, <span><math><mrow><mi>p</mi><mo>&lt;</mo><mo>.</mo><mn>001</mn></mrow></math></span>). Anterior-posterior length emerged as the primary predictor of sagittal stiffness (flexion: <span><math><mrow><mi>r</mi><mo>&gt;</mo><mn>0.70</mn></mrow></math></span>; extension: <span><math><mrow><mi>r</mi><mo>&gt;</mo><mn>0.75</mn></mrow></math></span>) and torsional resistance (<span><math><mrow><mi>r</mi><mo>&gt;</mo><mn>0.50</mn></mrow></math></span>), linked to altered moment arm mechanics. The nucleus pulposus volume ratio moderately affected intradiscal pressure (<span><math><mrow><mi>r</mi><mo>&gt;</mo><mn>0.30</mn></mrow></math></span>, <span><math><mrow><mi>p</mi><mo>&lt;</mo><mo>.</mo><mn>05</mn></mrow></math></span>) but showed negligible impact on segmental stiffness. This parametric modelling framework facilitates systematic investigation of L-IVD biomechanics across anatomical variations. Additionally, these findings advocate for microstructure-informed computational models to optimize personalized implant designs and biomechanical assessments.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 3","pages":"Pages 496-506"},"PeriodicalIF":5.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144654464","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":"Movement and force dynamics in bimanual cooperative tasks in chronic stroke and healthy individuals","authors":"J. Podobnik,&nbsp;M. Munih,&nbsp;M. Mihelj","doi":"10.1016/j.bbe.2025.07.002","DOIUrl":"10.1016/j.bbe.2025.07.002","url":null,"abstract":"<div><div>Stroke rehabilitation often involves the use of haptic robots to improve motor control and bimanual coordination. This study examines how damping affects movement and force dynamics in bimanual tasks performed by healthy participants and participants with chronic stroke using a haptic robotic system equipped with force sensors for each hand. Participants completed tasks at three damping levels: <span><math><mrow><mn>0</mn><mspace></mspace><mfrac><mrow><mi>N</mi></mrow><mrow><mi>m</mi><mo>/</mo><mi>s</mi></mrow></mfrac></mrow></math></span> (no damping), <span><math><mrow><mn>20</mn><mspace></mspace><mfrac><mrow><mi>N</mi></mrow><mrow><mi>m</mi><mo>/</mo><mi>s</mi></mrow></mfrac></mrow></math></span> (low damping), and <span><math><mrow><mn>40</mn><mspace></mspace><mfrac><mrow><mi>N</mi></mrow><mrow><mi>m</mi><mo>/</mo><mi>s</mi></mrow></mfrac></mrow></math></span> (moderate damping). Key parameters for trajectory of movement, velocity, manipulation force, and internal force were analyzed to assess movement stability and control. The results revealed that damping <span><math><mrow><mn>20</mn><mspace></mspace><mfrac><mrow><mi>N</mi></mrow><mrow><mi>m</mi><mo>/</mo><mi>s</mi></mrow></mfrac></mrow></math></span> effectively stabilized movements in persons with stroke, reducing velocity deviations and making their performance more comparable to healthy participants, without introducing excessive resistance. In contrast, damping <span><math><mrow><mn>40</mn><mspace></mspace><mfrac><mrow><mi>N</mi></mrow><mrow><mi>m</mi><mo>/</mo><mi>s</mi></mrow></mfrac></mrow></math></span> acted as resistance training. Participants with stroke exhibited consistently higher internal forces than healthy participants, reflecting compensatory strategies and inefficient motor control. These findings demonstrate that low damping (<span><math><mrow><mn>20</mn><mspace></mspace><mfrac><mrow><mi>N</mi></mrow><mrow><mi>m</mi><mo>/</mo><mi>s</mi></mrow></mfrac></mrow></math></span>) offers an optimal balance between movement stabilization and resistance, highlighting its potential as a rehabilitation strategy, while moderate damping (<span><math><mrow><mn>40</mn><mspace></mspace><mfrac><mrow><mi>N</mi></mrow><mrow><mi>m</mi><mo>/</mo><mi>s</mi></mrow></mfrac></mrow></math></span>) may be reserved for resistance training.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 3","pages":"Pages 476-484"},"PeriodicalIF":5.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144611678","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}