Biocybernetics and Biomedical Engineering最新文献

{"title":"Modulation of brain-heart interaction by stimuli: Evidence from heartbeat evoked potential and bidirectional couple model","authors":"Jie Wang ,&nbsp;Liang Zhao ,&nbsp;Xingwei An","doi":"10.1016/j.bbe.2026.01.007","DOIUrl":"10.1016/j.bbe.2026.01.007","url":null,"abstract":"<div><div>External sensory stimuli play a critical role in modulating brain–heart interaction (BHI) and cognitive processes, yet their impact on the bidirectional nature of BHI remains poorly understood. Additionally, the association between heartbeat evoked potentials (HEP), a key metric in BHI research, and bidirectional BHI requires further validation. This study systematically investigated the effects of visual, auditory, and audiovisual stimuli on BHI, as well as the influence of the cardiac cycle on external stimulus processing, using an oddball paradigm combined with HEP analysis and synthetic data generation (SDG) modeling. Results revealed that auditory stimuli significantly enhanced late HEP amplitudes in the occipital region, while visual and audiovisual stimuli suppressed HEP responses, likely due to competition for neural resources during perceptual processing. Additionally, there was no significant difference in the P300 amplitude induced by non-target stimuli between systole and diastole, implying that the brain’s sensitivity to external stimuli may be largely unaffected by the phase of the cardiac cycle. The bidirectional BHI model further demonstrated increased heart-to-brain theta and alpha-band coupling under external stimuli, supporting the role of ascending cardiac signals in cognitive modulation. Moreover, this study introduced a novel HEP feature—heartbeat evoked intensity (HEI)—to quantify the brain’s response to cardiac signals by extracting the area under the HEP curve following the R-wave, serving as a relative index of heartbeat-related cortical activity across conditions. Strong correlations between HEI, heartbeat evoked oscillations (HEO), and heart-to-brain SDG coupling coefficients validated the bottom-up directionality of HEP. These findings highlight the differential effects of sensory modalities on BHI, advance our understanding of bidirectional brain–heart mechanisms, and provide new insights into the role of BHI in cognitive and clinical research.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"46 1","pages":"Pages 211-223"},"PeriodicalIF":6.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146173104","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 dynamic spectrum driven network for enhanced multimodal emotion recognition with EEG and ECG signals","authors":"Priyadarsini Samal,&nbsp;Mohammad Farukh Hashmi","doi":"10.1016/j.bbe.2026.01.002","DOIUrl":"10.1016/j.bbe.2026.01.002","url":null,"abstract":"<div><div>For effective human–machine interaction, utilizing various physiological cues to recognize emotions is crucial. Using many physiological signals yields more accurate outcomes when recognizing human emotional states. This study introduces a new approach called DSDNet (Dynamic spectrum driven network) to emotion recognition using Electroencephalogram (EEG) and Electrocardiogram (ECG) signals. The method involves a dynamic time frequency analysis technique that combines synchrosqueezed transform with short time fast fractional Fourier transform. The signals are divided into segments, and the corresponding time–frequency spectrograms from EEG and ECG signals are combined for additional assessment and the importance of these spectrogram features are visualized by using SHAP deep explainer. Subsequently, these spectrogram features are provided to a simple efficient convolutional neural network for classification. The proposed approach utilized the DREAMER and AMIGOS datasets for development and comparison with several high-performance algorithms. This approach surpassed the most notable results in the existing literature, with an accuracy of 98.6%, 98.9%, and 99.2% for the valence, arousal, and dominance categories respectively, when applied to the DREAMER dataset. Similarly, when applied to the AMIGOS dataset, it achieved accuracies of 98.8%, 99.5%, and 99.4% for all three categories. Therefore, the findings of this research indicate that by incorporating various physiological signals and modern approaches in the field of human–machine interaction, it is possible to greatly enhance the accuracy of emotion detection results.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"46 1","pages":"Pages 139-161"},"PeriodicalIF":6.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146077105","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":"Monitoring stroke volume continuously and autonomously using an epicardial accelerometer","authors":"Vetle Christoffer Frostelid ,&nbsp;Lars-Egil R. Hammersboen ,&nbsp;Manuel Villegas-Martinez ,&nbsp;Fred-Johan Pettersen ,&nbsp;Ole Jakob Elle ,&nbsp;Per Steinar Halvorsen ,&nbsp;Espen W. Remme","doi":"10.1016/j.bbe.2026.01.001","DOIUrl":"10.1016/j.bbe.2026.01.001","url":null,"abstract":"<div><div>The incorporation of miniaturised accelerometers into cardiac implants used in current clinical practice endows access to continuous measurement of heart wall motion and vibrations which may be used to monitor cardiac function without additional risk to patient safety. In this work the path length travelled throughout a heartbeat by an accelerometer attached to the lateral epicardium of the left ventricle is presented as a surrogate for stroke volume, a fundamental parameter of cardiac function. A strong correlation was found between path length and stroke volume in experimental animal data (n=13). Additionally, mathematical models for path length and stroke volume were derived using physiological and geometrical principles, and validated against a measured ground truth. Using the models, path length and stroke volume were both shown to respond similarly to changes in the size of the left ventricle and its contraction, further supporting and explaining the link between the two. The theoretical and empirical evidence presented therefore supports the use of epicardially attached accelerometers for continuous and autonomous monitoring of stroke volume, encouraging further development of epicardial motion sensors for the purpose of clinical or remote assessment of cardiac function.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"46 1","pages":"Pages 130-138"},"PeriodicalIF":6.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977058","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":"Effect of non-Newtonian rheological models on pulsatile hemodynamics in patients-specific venous models of pulsatile tinnitus","authors":"Zhenxia Mu ,&nbsp;Ben Liu ,&nbsp;Yicheng Han ,&nbsp;Lihui Zhuang ,&nbsp;Xiaoyu Qiu ,&nbsp;Heyu Ding ,&nbsp;Shusheng Gong ,&nbsp;Guopeng Wang ,&nbsp;Bin Gao ,&nbsp;Youjun Liu ,&nbsp;Shifeng Yang ,&nbsp;Zhenchang Wang ,&nbsp;Pengfei Zhao ,&nbsp;Ximing Wang","doi":"10.1016/j.bbe.2025.10.002","DOIUrl":"10.1016/j.bbe.2025.10.002","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 4","pages":"Pages 630-641"},"PeriodicalIF":6.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145362280","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 wireless, implantable, dual-channel phrenic nerve stimulator for diaphragm pacing using electromagnetic resonance coupling","authors":"Xiaoyu Gu ,&nbsp;Wei Zhong ,&nbsp;Yan Shi ,&nbsp;Meng Xu ,&nbsp;Zhaohui Tong ,&nbsp;Yixuan Wang","doi":"10.1016/j.bbe.2025.08.007","DOIUrl":"10.1016/j.bbe.2025.08.007","url":null,"abstract":"<div><h3>Objectives</h3><div>Implantable diaphragm pacing (DP) system can effectively restore patients’ breathing.</div><div>Conventional diaphragm pacemakers have some practical limitations, such as transmission stability and high price. This study proposes an innovative, wirelessly powered dual-channel and inexpensive DP system to overcome some of these constraints.</div></div><div><h3>Methods</h3><div>The system realizes wireless power supply based on electromagnetic resonance coupling to improve stability. It comprised an external controller, two off-body transmitters and two in-vivo rectifier-integrated receivers. PCB spiral coils are used for energy transmission in wireless systems to ensure system stability and convenient processing. Receiver encapsulated with biocompatible PDMS convert received power into electrical stimulation energy. Stimulation waveform, multi-media environment and animal experimental tests were conducted to validate system’s performance. Specific absorption rate (SAR) in human tissue was calculated to confirm safety of implantation.</div></div><div><h3>Results</h3><div>Electrical stimulation parameters of the proposed DP system can be precisely adjusted. The stimulation amplitude range is 3–12 V with 0.1 V step resolution. Pulse width and frequency are adjustable from 100-300 µs and 10–100 Hz respectively. The breathing cycle and inhalation time can also be set individually. Wireless energy transmission has wide transmission distance (＞14 mm), good anti-offset capability (horizontal offset＞8mm) and implantation safety (SAR＜1.6 W/kg). Further time series of stimulation signals issued by the two channels are synchronized. The developed system effectively realizes respiratory response of animals to bilateral phrenic nerve stimulation with 17 mm wireless energy transmission distance and implantation of two receivers in vivo.</div></div><div><h3>Conclusion</h3><div>Our work provides a new optimization scheme for the design of implantable diaphragm pacemaker.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 4","pages":"Pages 593-607"},"PeriodicalIF":6.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916952","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":"Design and development of a systematic validation protocol for synthetic melanoma images for responsible use in medical artificial intelligence","authors":"Alessio Luschi ,&nbsp;Linda Tognetti ,&nbsp;Alessandra Cartocci ,&nbsp;Elisa Cinotti ,&nbsp;Giovanni Rubegni ,&nbsp;Laura Calabrese ,&nbsp;Martina D’onghia ,&nbsp;Martina Dragotto ,&nbsp;Elvira Moscarella ,&nbsp;Gabriella Brancaccio ,&nbsp;Giulia Briatico ,&nbsp;Camila Scharf ,&nbsp;Dario Buononato ,&nbsp;Vittorio Tancredi ,&nbsp;Carmen Cantisani ,&nbsp;Camilla Chello ,&nbsp;Luca Ambrosio ,&nbsp;Pietro Scribani Rossi ,&nbsp;Marco Virone ,&nbsp;Giovanni Pellacani ,&nbsp;Ernesto Iadanza","doi":"10.1016/j.bbe.2025.09.001","DOIUrl":"10.1016/j.bbe.2025.09.001","url":null,"abstract":"<div><div>Malignant melanoma is the deadliest form of skin cancer, and artificial intelligence could help address its diagnostic challenges. Generative Adversarial Networks (GANs) can generate synthetic dermoscopic images to augment limited real datasets, but the lack of standardised validation protocols holds back models’ reliability and clinicians’ trust. This study aims to design and develop a systematic validation protocol combining quantitative metrics and qualitative expert assessments to evaluate the realism, fidelity, diversity, and usefulness of synthetic dermoscopic melanoma images. A StyleGAN2 model, designed and trained in a previous study, was selected for its superior quantitative performance and exploited to generate 25 synthetic melanoma images, matched with 25 real images. A panel of 17 dermoscopists assessed the images using a 7-point Likert scale, across multiple qualitative attributes (real vs. synthetic, skin texture, visual realism, and confidence) and pattern analysis. Accuracy, sensitivity, specificity, Fleiss’ Kappa, and Krippendorff’s Alpha were calculated to analyse inter-rater agreement and evaluation outcomes. Accuracy in real vs synthetic images classification was moderate (64 %), with sensitivity at 73 % and specificity at 56 %, with poor inter-rater concordance over qualitative attributes. Synthetic images obtained superior scores in medium visual and overall realism, and confidence level, while the frequency of recognition of pigment network-patterns was comparable with real images. The proposed holistic validation protocol can effectively estimate the quality level of synthetic dermoscopic images, regardless of the architecture of the model used for generation, offering an objective and reliable evaluation tool, as qualitative evaluations remain crucial to ensure their safe deployment in clinical settings.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 4","pages":"Pages 608-616"},"PeriodicalIF":6.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099872","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":"Interferometric speckle contrast optical spectroscopy (iSCOS) in continuous-wave parallel interferometric near-infrared spectroscopy (CW-πNIRS)","authors":"Klaudia Nowacka-Pieszak ,&nbsp;Saeed Samaei ,&nbsp;Dawid Borycki","doi":"10.1016/j.bbe.2025.11.001","DOIUrl":"10.1016/j.bbe.2025.11.001","url":null,"abstract":"<div><div>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, <em>in vivo</em> experiments confirmed the method’s potential for effective human cerebral blood flow monitoring, highlighting practical advantages and providing a clear pathway towards clinical implementation.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 4","pages":"Pages 669-684"},"PeriodicalIF":6.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145465358","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":"Enhanced computer-aided system for breast lesion classification and grading using novel radio frequency time series approach","authors":"Elaheh Norouzi Ghehi ,&nbsp;Ali Fallah ,&nbsp;Saeid Rashidi ,&nbsp;Maryam Mehdizadeh Dastjerdi","doi":"10.1016/j.bbe.2025.10.003","DOIUrl":"10.1016/j.bbe.2025.10.003","url":null,"abstract":"<div><h3>Objective</h3><div>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.</div></div><div><h3>Materials and methods</h3><div>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.</div></div><div><h3>Results</h3><div>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.</div></div><div><h3>Conclusions</h3><div>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.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 4","pages":"Pages 655-668"},"PeriodicalIF":6.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145416928","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":"Estimating core body temperature from heart rate using a residual-compensated adaptive Kalman filter","authors":"Yuanzhe Zhao ,&nbsp;Jeroen H.M. Bergmann","doi":"10.1016/j.bbe.2025.10.001","DOIUrl":"10.1016/j.bbe.2025.10.001","url":null,"abstract":"<div><div>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.</div><div>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.</div><div>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.</div><div>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.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 4","pages":"Pages 617-629"},"PeriodicalIF":6.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145323893","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":"The influence of tissue conductivity uncertainty on the nerve activation thresholds in non-invasive electrical phrenic nerve stimulation","authors":"Laureen Wegert ,&nbsp;Luca Di Rienzo ,&nbsp;Lorenzo Codecasa ,&nbsp;Sicheng An ,&nbsp;Marek Ziolkowski ,&nbsp;Alexander Hunold ,&nbsp;Irene Lange ,&nbsp;Tim Kalla ,&nbsp;Jens Haueisen","doi":"10.1016/j.bbe.2025.11.003","DOIUrl":"10.1016/j.bbe.2025.11.003","url":null,"abstract":"<div><div>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.</div><div>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.</div><div>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.</div><div>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.</div></div>","PeriodicalId":55381,"journal":{"name":"Biocybernetics and Biomedical Engineering","volume":"45 4","pages":"Pages 697-706"},"PeriodicalIF":6.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145617673","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}