Biocybernetics and Biomedical Engineering最新文献_第2页

Scapulohumeral rhythm preserves glenohumeral stability: Insights from a biomechanical simulation 肩胛骨节律保持肩关节稳定性：来自生物力学模拟的见解

IF 6.6 2区医学 Q1 ENGINEERING, BIOMEDICAL

Biocybernetics and Biomedical Engineering

Pub Date : 2025-12-04 DOI: 10.1016/j.bbe.2025.11.002

Matej Daniel , Jan Votava , Júlia Bodnárová , Adam Kratochvíll , Zbyněk Šika , David Pokorný , Petr Fulín

The shoulder’s dynamic function is largely influenced by scapulohumeral rhythm (SHR), a coordinated movement of the scapula and humerus that facilitates a safe range of motion. While SHR has been described and quantified in terms of shoulder kinematics, its specific contribution to glenohumeral joint stability. This study aims to estimate the impact of SHR on glenohumeral stability using a biomechanical model. A five-segment musculoskeletal model based on the work of Wu et al. (2016) was implemented in OpenSim. Three SHR patterns and two loading scenarios were evaluated: a fixed scapula, a humeral-to-scapular motion ratio, and an experimentally measured SHR with free abduction or abduction while holding a 2 kg weight in the hand. Muscle forces and glenohumeral stability ratios were calculated using static optimization, and the model predictions were compared to electromyography and in vivo joint force data. While glenohumeral contact forces showed minimal variation across different SHR conditions, the stability ratio analysis revealed that the absence of SHR significantly increased the risk of joint instability. In scenarios without SHR, even small shoulder elevations resulted in overloading of the superior glenoid. The addition of weight further destabilized the joint, while substantially increasing glenohumeral force. SHR does not reduce the overall glenohumeral load but plays a critical role in maintaining glenohumeral stability, particularly during early phases of shoulder elevation and when holding additional weight. These findings highlight the importance of scapular kinematics in shoulder joint function and may have implications for managing shoulder pathologies such as rotator cuff tears and impingement, where scapular motion is often compromised.

肩胛骨和肱骨的协调运动促进了安全的活动范围，肩胛骨和肱骨的协调运动在很大程度上影响了肩胛骨和肱骨的动态功能。虽然SHR已经在肩关节运动学方面被描述和量化，但它对肩关节稳定性的具体贡献。本研究旨在利用生物力学模型估计SHR对肩关节稳定性的影响。基于Wu etal .（2016）的工作，在OpenSim中实现了一个五段肌肉骨骼模型。评估了三种SHR模式和两种加载情景：固定肩胛骨，肱骨与肩胛骨的运动比，以及实验测量的自由外展或手握2 kg重量时外展的SHR。采用静态优化计算肌肉力和肩关节稳定性比，并将模型预测结果与肌电图和体内关节力数据进行比较。虽然肩关节接触力在不同SHR条件下的变化很小，但稳定性比分析显示，没有SHR会显著增加关节不稳定的风险。在没有SHR的情况下，即使是很小的肩部抬高也会导致上肩关节超载。重量的增加进一步破坏了关节的稳定性，同时大大增加了肩关节的受力。SHR不能减少肩关节的整体负荷，但在维持肩关节稳定性方面起着关键作用，特别是在肩关节抬高的早期阶段和负重时。这些发现强调了肩胛骨运动在肩关节功能中的重要性，并可能对肩关节疾病的治疗有启示，如肩袖撕裂和撞击，肩胛骨运动经常受到损害。

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引用次数: 0

Tailoring Endoscopic sleeve gastroplasty: computational biomechanics for the evaluation and prediction of post-surgical outcomes 裁剪内镜下袖胃成形术：用于评估和预测术后结果的计算生物力学

IF 6.6 2区医学 Q1 ENGINEERING, BIOMEDICAL

Biocybernetics and Biomedical Engineering

Pub Date : 2025-12-03 DOI: 10.1016/j.bbe.2025.11.006

Ilaria Toniolo , Emanuele Luigi Carniel , Claudio Fiorillo , Giuseppe Quero , Silvana Perretta , Alice Berardo

Endoscopic Sleeve Gastroplasty (ESG) is currently being used successfully in people with obesity. However, potential long-term side effects are still unknown. Computational biomechanics has emerged as a valid tool to improve the intervention effectiveness.

The aim of this work is to provide an in silico framework to estimate stomach mechanics, as volumetric capacity, structural stiffness, and wall tissue strain, in response to food intake before and after ESG. A cohort of patients who underwent ESG was studied to rationally analyze the reduction in gastric volume and the changes in structural response and strain distribution. Computational predictions were compared with Magnetic Resonance Imaging (MRI) data from post-operative stomachs, allowing the reliability and reproducibility of the methodology to be assessed. Significant differences in stomach mechanics before and after surgery were observed, considering both structural stiffness and tissue strain distribution. This difference may lead to improper activation of mechanoreceptors and thus to variations in satiety after ESG.

The results confirm the suitability of the in silico approach for evaluating bariatric surgery in the short-term, because it shed light on the reduction of stomach capacity and pressurization depending on the amount of food ingested, on the variation of tissue strain distribution, giving to the surgeon information that are currently not available. Leveraging computational modeling may help prevent complications, such as reflux or misplacement of sutures, and enhance outcomes by prescribing gastric-wall loading conditions associated with lower postoperative weight-regain rates.

内窥镜套管胃成形术（ESG）目前已成功用于肥胖患者。然而，潜在的长期副作用仍然未知。计算生物力学已成为提高干预效果的有效工具。这项工作的目的是提供一个计算机框架来估计胃力学，如体积容量、结构刚度和壁组织应变，在ESG前后对食物摄入的反应。研究了一组行ESG的患者，以合理分析胃容量的减少以及结构反应和应变分布的变化。将计算预测与术后胃磁共振成像（MRI）数据进行比较，从而评估该方法的可靠性和可重复性。考虑到结构刚度和组织应变分布，观察到手术前后胃力学的显著差异。这种差异可能导致机械感受器的不当激活，从而导致ESG后饱腹感的变化。结果证实了计算机方法在短期内评估减肥手术的适用性，因为它揭示了胃容量和压力的减少取决于摄入的食物量，组织应变分布的变化，为外科医生提供了目前无法获得的信息。利用计算模型可以帮助预防并发症，如反流或缝合线错位，并通过规定与较低术后体重恢复率相关的胃壁负荷条件来提高结果。

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引用次数: 0

A Complexity-Based analysis of postural stability dynamics during gait on dry and slippery surfaces 基于复杂性的干滑地面步态姿态稳定性动力学分析

IF 6.6 2区医学 Q1 ENGINEERING, BIOMEDICAL

Biocybernetics and Biomedical Engineering

Pub Date : 2025-11-26 DOI: 10.1016/j.bbe.2025.11.005

Mahdi Yousefi Azar Khanian , Zahra Sadat Hosseni , S.Mohammadreza Hashemi Gholpayeghani , Mostafa Rostami

Human postural stability represents a complex, nonlinear system influenced by a range of biomechanical and environmental factors. The trajectories of the center of pressure (CoP) serve as key indicators of this system’s underlying dynamics and are increasingly being analyzed using nonlinear methods. However, the impact of surface-induced instability during gait remains underexplored. This study aimed to analyze CoP behavior during gait on stable (dry) and unstable (slippery) surfaces by testing three hypotheses: (1) task-induced instability is associated with an increase in CoP complexity; (2) individual variability amplifies dynamic fluctuations under unstable conditions; and (3) repeated exposure to the task attenuates this complexity. Twenty healthy young males completed each walking task three times. CoP dynamics were quantified using nonlinear analyses, including phase-space reconstruction (embedding dimension and time lag) and correlation dimension (CD).

Complexity metrics, specifically the optimal embedding dimension and CD, were significantly elevated during the slippery surface condition, clearly distinguishing between the two task environments (p < 0.001, classification accuracy > 90 %). The greater variability in features observed under the slippery condition suggested broader dynamic adaptations to instability. Additionally, the reduction in CD across repeated trials indicated a moderating effect of prior exposure.

The findings support all three hypotheses, demonstrating the effectiveness of CoP-based nonlinear measures in capturing adaptive postural responses to changing stability demands. This study contributes a novel multi-trial nonlinear analysis approach for evaluating dynamic postural control under environmental challenges.

人体姿势稳定性是一个复杂的非线性系统，受一系列生物力学和环境因素的影响。压力中心（CoP）轨迹作为该系统潜在动力学的关键指标，越来越多地使用非线性方法进行分析。然而，在步态过程中，表面引起的不稳定的影响仍未得到充分的研究。本研究旨在通过测试三个假设来分析在稳定（干燥）和不稳定（湿滑）表面上行走时的CoP行为：(1)任务诱导的不稳定性与CoP复杂性的增加有关；(2)个体变异放大了不稳定条件下的动态波动；(3)反复接触任务会降低这种复杂性。20名健康的年轻男性完成每项行走任务三次。采用非线性分析方法，包括相空间重构（嵌入维数和时滞）和相关维数（CD），对CoP动力学进行了量化。在光滑表面条件下，复杂性指标，特别是最佳嵌入维数和CD显著提高，明显区分了两种任务环境（p < 0.001，分类准确率>； 90%）。在光滑条件下观察到的特征的较大变异性表明对不稳定的更广泛的动态适应。此外，反复试验中CD的减少表明了先前暴露的调节作用。研究结果支持所有这三个假设，证明了基于cop的非线性测量在捕获对变化的稳定性需求的适应性姿势反应方面的有效性。该研究为评估环境挑战下的动态姿态控制提供了一种新的多试验非线性分析方法。

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引用次数: 0

Effect of non-Newtonian rheological models on pulsatile hemodynamics in patients-specific venous models of pulsatile tinnitus 非牛顿流变学模型对搏动性耳鸣患者特异性静脉模型搏动血流动力学的影响

IF 6.6 2区医学 Q1 ENGINEERING, BIOMEDICAL

Biocybernetics and Biomedical Engineering

Pub Date : 2025-10-01 DOI: 10.1016/j.bbe.2025.10.002

Zhenxia Mu , Ben Liu , Yicheng Han , Lihui Zhuang , Xiaoyu Qiu , Heyu Ding , Shusheng Gong , Guopeng Wang , Bin Gao , Youjun Liu , Shifeng Yang , Zhenchang Wang , Pengfei Zhao , Ximing Wang

Hemodynamic factors play a crucial role in the pathogenesis of venous pulsatile tinnitus (PT). The selection of an appropriate blood viscosity model is therefore essential for accurately capturing hemodynamic characteristics in numerical simulations. This study aimed to investigate and compare the effects of different blood rheology models on hemodynamic parameters in patients with venous PT. Numerical simulation of pulsatile blood flow was conducted in three-dimensional patient-specific models with sigmoid sinuses wall dehiscence (SSWD) accompanied by sigmoid sinuses diverticulum (SSD) or transverse sinus stenosis. Different blood rheology models were employed in the simulations, including the Newtonian, Power law, Carreau, and Herschel-Bulkley models. Results demonstrated that unfavorable hemodynamics, characterized by high-velocity patterns and abnormal distributions of wall pressure, wall shear stress (WSS), and time-average WSS (TAWSS) in specific SSD and SSWD regions, could increase the risk of venous PT. Both Newtonian and non-Newtonian models predicted comparable distributions of hemodynamic parameters. However, differences in magnitude were observed, particularly in the SSD and SSWD regions. The Power law model exhibited the most pronounced differences, predicting the lowest velocity in the SSD region and the highest wall pressure, WSS, and TAWSS in the SSWD region. The Herschel-Bulkley model showed similar trends but with less extreme magnitudes. The Carreau model was closely aligned with the Newtonian model. Although the Newtonian model generally predicted hemodynamic parameter distributions comparable to those of non-Newtonian models, marked differences were observed in key regions (SSD and SSWD) critically involved in venous PT pathogenesis. Therefore, selecting an appropriate viscosity model is essential for accurately assessing hemodynamic characteristics within these specific regions.

血流动力学因素在静脉搏动性耳鸣的发病机制中起着至关重要的作用。因此，选择合适的血液粘度模型对于在数值模拟中准确捕获血流动力学特性至关重要。本研究旨在探讨和比较不同血液流变学模型对静脉PT患者血流动力学参数的影响，在乙状窦壁裂（SSWD）伴乙状窦憩室（SSD）或横窦狭窄的三维患者特异性模型中，对脉动血流进行数值模拟。在模拟中采用了不同的血液流变学模型，包括牛顿模型、幂律模型、careau模型和Herschel-Bulkley模型。结果表明，在特定的SSD和SSWD区域，以高速模式和壁压、壁剪切应力（WSS）和时间平均WSS （TAWSS）的异常分布为特征的不利血流动力学可增加静脉PT的风险。牛顿模型和非牛顿模型预测的血流动力学参数分布相似。然而，观察到的幅度差异，特别是在SSD和SSWD区域。幂律模型表现出最明显的差异，预测了SSD区域的最低速度，以及SSWD区域的最高壁压、WSS和TAWSS。Herschel-Bulkley模型显示了类似的趋势，但幅度没有那么极端。卡罗模型与牛顿模型非常接近。尽管牛顿模型预测的血流动力学参数分布与非牛顿模型一般相当，但在静脉PT发病的关键区域（SSD和SSWD）中观察到显著差异。因此，选择合适的粘度模型对于准确评估这些特定区域的血流动力学特性至关重要。

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引用次数: 0

Interferometric speckle contrast optical spectroscopy (iSCOS) in continuous-wave parallel interferometric near-infrared spectroscopy (CW-πNIRS) 连续波平行干涉近红外光谱（CW-πNIRS）中的干涉散斑对比光谱（iSCOS）

IF 6.6 2区医学 Q1 ENGINEERING, BIOMEDICAL

Biocybernetics and Biomedical Engineering

Pub Date : 2025-10-01 DOI: 10.1016/j.bbe.2025.11.001

Klaudia Nowacka-Pieszak , Saeed Samaei , Dawid Borycki

Optical methods enable continuous, noninvasive cerebral blood flow (CBF) monitoring. Diffuse correlation spectroscopy (DCS) estimates CBF through temporal correlation analysis of scattered light but is limited by low detection throughput. Parallelizing DCS enhances performance but requires costly ultra-fast (∼1 MHz) detectors, complicating continuous measurements. An alternative approach analyzes spatial correlations using speckle contrast, inversely proportional to blood flow, captured with slower two-dimensional sensors. In this study, we present continuous-wave parallel interferometric near-infrared spectroscopy (CW-πNIRS), employing interferometry combined with a high-speed 2D camera, as a novel method uniquely suited for spatial correlation measurements. By leveraging interferometric detection, our approach provides a synthetic multi-exposure capability for direct quantitative comparisons between spatial (speckle contrast) and temporal (autocorrelation) methods for CBF monitoring. Numerical simulations, incorporating interferometric reference fields, and tissue-mimicking phantom validations demonstrated robust, and stable speckle contrast estimates. Finally, in vivo experiments confirmed the method’s potential for effective human cerebral blood flow monitoring, highlighting practical advantages and providing a clear pathway towards clinical implementation.

光学方法可以实现连续的、无创的脑血流（CBF）监测。漫射相关光谱学（DCS）通过散射光的时间相关分析来估计CBF，但受低检测吞吐量的限制。并行DCS提高了性能，但需要昂贵的超高速（~ 1 MHz）检测器，使连续测量复杂化。另一种方法是使用散斑对比度分析空间相关性，与血流成反比，用较慢的二维传感器捕获。在这项研究中，我们提出了连续波平行干涉近红外光谱（CW-πNIRS），该方法采用干涉测量与高速二维相机相结合，是一种独特适用于空间相关测量的新方法。通过利用干涉检测，我们的方法为CBF监测的空间（散斑对比）和时间（自相关）方法之间的直接定量比较提供了综合的多曝光能力。结合干涉参考场的数值模拟和组织模拟幻象验证证明了鲁棒和稳定的散斑对比度估计。最后，体内实验证实了该方法有效监测人脑血流量的潜力，突出了实用性优势，为临床应用提供了明确的途径。

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引用次数: 0

Enhanced computer-aided system for breast lesion classification and grading using novel radio frequency time series approach 使用新型射频时间序列方法增强乳腺病变分类和分级的计算机辅助系统

IF 6.6 2区医学 Q1 ENGINEERING, BIOMEDICAL

Biocybernetics and Biomedical Engineering

Pub Date : 2025-10-01 DOI: 10.1016/j.bbe.2025.10.003

Elaheh Norouzi Ghehi , Ali Fallah , Saeid Rashidi , Maryam Mehdizadeh Dastjerdi

Objective

Breast cancer is the most common malignancy among women and leading cause of mortality. Accurate, non-invasive differentiation of benign and malignant lesions is a clinical priority to reduce unnecessary biopsies and enable timely treatment. Elastography and RF time series (RF TS) processing are effective ultrasound-based techniques for tissue characterization. To improve their accuracy, we introduced an innovative approach called RFTSDP (RF Time Series Dynamic Processing). In RFTSDP, data are recorded during mechanical stimulation, revealing tissue properties in RF echoes. Extracting relevant features enhances computer-aided methods and improves tissue classification and grading.

Materials and methods

An implement was developed to induce vibrations at different frequencies. Data were collected from ex-vivo tissues embedded in normal mimicking phantoms. Raw focused, raw, and beamformed ultrafast data were recorded under no stimulation, constant force, and various vibrational stimulations using the Supersonic Imaging Aixplorer ultrasound system. Features were extracted from each RF TS across the time, time–frequency, spectral, and non-linear domains. Multiple classifiers were evaluated, among which support vector machines with different kernels achieved the best results.

Results

Beyond the classification of cancerous versus non-cancerous tissue, we also classified different cancerous lesion types and graded invasive ductal carcinoma. The best results were achieved with beamformed ultrafast data under 65 Hz vibrational stimulation. The mean classification accuracies for 2-, 3-, and 5-class were 99.78 %, 99.06 % and 99.32 %, respectively.

Conclusions

The outcomes affirm that applying vibration, particularly at an optimal frequency, enhances breast tissue classification. The proposed method demonstrated efficacy not only in distinguishing between cancerous and non-cancerous lesions but also in grading cancerous tissues.

目的乳腺癌是妇女中最常见的恶性肿瘤，也是导致死亡的主要原因。准确、无创地鉴别良恶性病变是减少不必要的活检和及时治疗的临床重点。弹性成像和射频时间序列（RF TS）处理是有效的基于超声的组织表征技术。为了提高它们的精度，我们引入了一种称为RFTSDP （RF时间序列动态处理）的创新方法。在RFTSDP中，在机械刺激过程中记录数据，揭示射频回波中的组织特性。提取相关特征增强了计算机辅助方法，改进了组织分类和分级。材料和方法研制了一种装置来诱导不同频率的振动。数据收集自植入正常模拟模型的离体组织。使用超声成像aiexplorer超声系统，在无刺激、恒力和各种振动刺激下记录原始聚焦、原始和波束形成的超快数据。从每个RF TS中提取时间、时频、频谱和非线性域的特征。对多个分类器进行了评价，其中具有不同核的支持向量机获得了最好的分类效果。结果除了癌组织与非癌组织的分类外，我们还对浸润性导管癌进行了不同类型和分级的分类。在65 Hz的振动刺激下，波束形成的超快数据获得了最好的结果。2类、3类和5类的平均分类准确率分别为99.78%、99.06%和99.32%。结论应用振动，特别是在最佳频率下，可以增强乳腺组织分类。所提出的方法不仅在区分癌性和非癌性病变方面有效，而且在癌性组织分级方面也有效。

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引用次数: 0

The influence of tissue conductivity uncertainty on the nerve activation thresholds in non-invasive electrical phrenic nerve stimulation 组织电导率不确定性对无创膈神经电刺激神经激活阈值的影响

IF 6.6 2区医学 Q1 ENGINEERING, BIOMEDICAL

Biocybernetics and Biomedical Engineering

Pub Date : 2025-10-01 DOI: 10.1016/j.bbe.2025.11.003

Laureen Wegert , Luca Di Rienzo , Lorenzo Codecasa , Sicheng An , Marek Ziolkowski , Alexander Hunold , Irene Lange , Tim Kalla , Jens Haueisen

Non-invasive phrenic nerve stimulation can be used to overcome diaphragm insufficiency caused by mechanical ventilation. Detailed models and electromagnetic simulations are used to suggest appropriate stimulation parameters, but require accurate tissue properties. However, a wide range of electrical conductivity values is known from the literature. Here, we aim to perform an uncertainty analysis of the nerve activation threshold and the potential distribution along the phrenic nerve due to uncertain tissue conductivites.

We built a generalized polynomial chaos (gPC) model to calculate the phrenic nerve activation threshold. It was based on a reduced order model of a detailed anatomical finite element model of the neck including 13 tissue types to calculate the potential distribution, followed by a biophysiological nerve model. The tissue conductivity values investigated here were for the compartments of fat, muscle, nerve, and soft tissue. Their influence on the nerve activation threshold was investigated by changing conductivity values of the single tissues and all tissues at a time within a Monte Carlo analysis using the gPC model.

The phrenic nerve activation threshold varied between 33.8 mA and 46.9 mA for the combined variation of the conductivity values. Sobol indices and global sensitivity coefficients indicated the highest influence for muscle conductivity value, followed by soft tissue, fat, and nerve tissue.

Our results may have implications for understanding the experimentally observed variation in individual phrenic nerve activation thresholds affected by physiological and pathological conductivity changes. Accurate electric properties of muscle and soft tissue and detailed geometric representations should be considered in electromagnetic simulations.

无创膈神经刺激可用于克服机械通气引起的膈肌功能不全。详细的模型和电磁模拟用于建议适当的刺激参数，但需要准确的组织特性。然而，从文献中已知电导率值的范围很广。在这里，我们的目的是进行神经激活阈值的不确定性分析和电位分布沿膈神经由于不确定的组织电导率。我们建立了广义多项式混沌（gPC）模型来计算膈神经的激活阈值。该方法基于包含13种组织类型的颈部详细解剖有限元模型的降阶模型计算电位分布，然后建立生物生理神经模型。这里研究的组织电导率值是针对脂肪、肌肉、神经和软组织的隔室。在使用gPC模型的蒙特卡罗分析中，通过改变单个组织和所有组织的电导率值，研究了它们对神经激活阈值的影响。电导率综合变化的膈神经激活阈值在33.8 ~ 46.9 mA之间。Sobol指数和整体敏感性系数对肌肉电导率的影响最大，其次是软组织、脂肪和神经组织。我们的结果可能有助于理解实验观察到的受生理和病理电导率变化影响的个体膈神经激活阈值的变化。电磁仿真应考虑肌肉和软组织的准确电特性和详细的几何表示。

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引用次数: 0

Estimating core body temperature from heart rate using a residual-compensated adaptive Kalman filter 利用残差补偿自适应卡尔曼滤波从心率估计核心体温

IF 6.6 2区医学 Q1 ENGINEERING, BIOMEDICAL

Biocybernetics and Biomedical Engineering

Pub Date : 2025-10-01 DOI: 10.1016/j.bbe.2025.10.001

Yuanzhe Zhao , Jeroen H.M. Bergmann

Accurate, real-time estimation of core body temperature is critical for preventing heat-related illness. While existing Kalman filter-based methods offer interpretable, single-input (heart rate) solutions, they are limited by fixed observation models that fail to capture the complex, non-linear, state-dependent dynamics of physiological signals.

To address this, we propose the Residual-Compensated Adaptive Kalman Filter (RCAKF), a novel hybrid framework. The RCAKF integrates a long short-term memory (LSTM) network to learn and correct structured, state-dependent errors in the observation model, alongside an adaptive noise estimator that dynamically adjusts for measurement uncertainty. This architecture enhances the classic Kalman filter with data-driven flexibility while maintaining its recursive structure and interpretability.

Evaluation was conducted on a controlled experimental dataset with 22 participants performing exercise and recovery under varied thermal conditions. Compared to five baseline models: extended Kalman filter (EKF: RMSE = 0.39 °C), the improved ECTemp model with a sigmoid observation function (ECTemp-S: RMSE = 0.40 °C), biphasic Kalman filter-based model (BKFB: RMSE = 0.48 °C), moving-average Kalman filter (MAKF: RMSE = 0.38 °C), and a standalone LSTM network (RMSE = 0.46 °C), RCAKF achieved the best accuracy with an RMSE of 0.31 °C.

By augmenting the Kalman filter with a learned residual correction and adaptive uncertainty, the RCAKF framework significantly enhances core temperature tracking from a single heart rate signal. Its accuracy and reliance on a single, common sensor make it a practical and promising solution for real-time deployment on wearable devices for safety monitoring.

准确、实时地估计核心体温对于预防与热有关的疾病至关重要。虽然现有的基于卡尔曼滤波的方法提供了可解释的单输入（心率）解决方案，但它们受到固定观察模型的限制，这些模型无法捕捉生理信号的复杂、非线性、状态依赖的动态。为了解决这个问题，我们提出了一种新的混合框架残余补偿自适应卡尔曼滤波器（RCAKF）。RCAKF集成了一个长短期记忆（LSTM）网络，用于学习和纠正观测模型中的结构化、状态相关错误，以及一个自适应噪声估计器，可动态调整测量不确定性。该结构增强了经典卡尔曼滤波器的数据驱动灵活性，同时保持了其递归结构和可解释性。对22名参与者在不同热条件下进行运动和恢复的受控实验数据集进行了评估。与扩展卡尔曼滤波（EKF: RMSE = 0.39°C）、具有s型观测函数的改进ECTemp模型（ECTemp- s: RMSE = 0.40°C）、基于双相卡尔曼滤波的模型（BKFB: RMSE = 0.48°C）、移动平均卡尔曼滤波（MAKF: RMSE = 0.38°C）和独立LSTM网络（RMSE = 0.46°C）等5种基线模型相比，RCAKF的RMSE为0.31°C，达到了最佳精度。通过使用学习残差校正和自适应不确定性增强卡尔曼滤波器，RCAKF框架显著增强了单次心率信号的核心温度跟踪。其准确性和对单个通用传感器的依赖使其成为可穿戴设备实时部署的实用且有前途的安全监控解决方案。

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引用次数: 0

Reevaluating performance in c-VEP BCIs: The impact of calibration time 重新评估c-VEP bci的性能：校准时间的影响

IF 6.6 2区医学 Q1 ENGINEERING, BIOMEDICAL

Biocybernetics and Biomedical Engineering

Pub Date : 2025-10-01 DOI: 10.1016/j.bbe.2025.10.006

Víctor Martínez-Cagigal , Eduardo Santamaría-Vázquez , Sergio Pérez-Velasco , Ana Martín-Fernández , Roberto Hornero

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.

编码调制视觉诱发电位（c-VEP）在非侵入性脑机接口（bci）中表现出很高的性能。最近，研究开始考虑视觉舒适等实际方面，其中非二进制序列和刺激空间频率的变化起着重要作用。然而，在性能比较中，校准要求仍未得到充分探讨。本研究旨在分析对基于c- vep的bci的实际应用至关重要的多变量权衡：解码精度，解码速度和校准时间。使用两个预先记录的数据集对视觉舒适度进行回顾性评估。模型通过不断增加的校准周期进行训练，并在不同的解码时间内进行测试，描绘学习和解码曲线。数据集包括32名健康受试者，具有不同的刺激范式：普通的非二进制刺激和具有空间频率变化的棋盘状二进制刺激。结果表明，在充分校准的情况下，所有条件的大平均精度均达到97%以上。然而，在校准时间和性能之间出现了明显的权衡。要在2秒的解码窗口内达到95%的平均精度，二进制刺激的平均校准时间为28.7 ± 19.0 s，非二进制刺激的平均校准时间为148.7 ± 72.3 s。基于二进制棋盘的空间频率为1.2 c/º（C016）的条件被证明是特别有效的，仅使用7.3秒的校准时间，在2秒的解码窗口内达到95%以上的准确率，并报告了视觉舒适度的显着改善。最小校准时间1 min被认为是充分估计大脑反应的必要条件，在模板匹配范式中至关重要。总之，实现最佳的c-VEP性能需要平衡校准时间、解码速度和精度以及视觉舒适性。

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引用次数: 0

A novel class of rank tests for high-dimensional data with an application to Alzheimer’s disease 一类新的高维数据秩检验及其在阿尔茨海默病中的应用

IF 6.6 2区医学 Q1 ENGINEERING, BIOMEDICAL

Biocybernetics and Biomedical Engineering

Pub Date : 2025-10-01 DOI: 10.1016/j.bbe.2025.10.005

Jan Kalina , Jaromir Kukal , Oldrich Vysata

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.

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 p-value of 0.004 was obtained, which is below the significance level

α = 0.05

, indicating a statistically significant difference.

脑电图（EEG）信号广泛应用于神经科学研究和生物医学应用，特别是用于患者和对照受试者两个队列之间的比较分析。在脑电图研究中，多变量双样本测试仍未得到充分利用，而多种比较程序往往被误用作为替代，导致误差控制不足。此外，现有的基于秩的测试仅依赖于欧几里得距离，对异常值缺乏鲁棒性。这项工作的目的是开发和评估一类新的基于秩的高维数据测试，该测试采用稳健的马氏点间距离，并展示其在脑电图信号分析中的实用价值。该类包括一个基于MRWCD（最小正则化加权协方差行列式）估计器的版本，它通过减轻异常值的影响来增强马氏距离的鲁棒性。为了说明这些测试的有效性，我们分析了来自28名阿尔茨海默病患者和146名健康对照者的1216个变量的脑电图数据。多变量测试的结果揭示了显著的发现，这些发现也在个体脑电图通道和频率的背景下进行了探讨。在测试的方法中，使用新提出的点间距离的基于等级的测试，特别是与Cucconi测试统计量相结合，产生了最强的结果。患者与对照组比较，p值为0.004，低于显著性水平α=0.05，差异有统计学意义。

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引用次数: 0