Biomedical Physics & Engineering Express最新文献

{"title":"An investigation of a passive BCI's performance for different body postures and presentation modalities.","authors":"Diana E Gherman, Laurens R Krol, Marius Klug, Thorsten O Zander","doi":"10.1088/2057-1976/adb58b","DOIUrl":"10.1088/2057-1976/adb58b","url":null,"abstract":"<p><p>Passive brain-computer interfaces (passive BCIs, pBCIs) enable computers to unobtrusively decipher aspects of a user's mental state in real time from recordings of brain activity, e.g. electroencephalography (EEG). When used during human-computer interaction (HCI), this allows a computer to dynamically adapt for enhancing the subjective user experience. For transitioning from controlled laboratory environments to practical applications, understanding BCI performance in real contexts is of utmost importance. Here, Virtual Reality (VR) can play a unique role: both as a fully controllable simulation of a realistic environment and as an independent, increasingly popular real application. Given the potential of VR as a dynamic and controllable environment, and the capability of pBCIs to enable novel modes of interaction, it is tempting to envision a future where pBCI and VR are seamlessly integrated. However, the simultaneous use of these two technologies-both of which are head-mounted-presents new challenges. Due to their immediate proximity, electromagnetic artifacts can arise, contaminating the EEG. Furthermore, the active movements promoted by VR can induce mechanical and muscular artifacts in the EEG. The varying body postures and display preferences of users further complicate the practical application of pBCIs. To address these challenges, the current study investigates the influence of body posture (sitting Versus standing) and display media (computer screen Versus VR) on the performance of a pBCI in assessing cognitive load. Our results show that these conditions indeed led to some changes in the EEG data; nevertheless, the ability of pBCIs to detect cognitive load remained largely unaffected. However, when a classifier trained in one context (body posture or modality) was applied to another (e.g., cross-task application), reductions in classification accuracy were observed. As HCI moves towards increasingly adaptive and more interactive designs, these findings support the expansive potential of pBCIs in VR contexts.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143413302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of internal scatter contribution to gonadal dose in colorectal radiotherapy.","authors":"Hyojun Park, Jung-In Kim, Chang Heon Choi, Jong Min Park, Seonghee Kang, Hyeongmin Jin, Eui Kyu Chie, Jaeman Son","doi":"10.1088/2057-1976/adc1cf","DOIUrl":"10.1088/2057-1976/adc1cf","url":null,"abstract":"<p><p>Colorectal cancer is among the most common cancers in terms of both incidence and mortality. External beam radiotherapy is frequently used to treat colorectal cancer. In colorectal radiotherapy, the gonad is considered as an organ that must be spared owing to its radiosensitivity. However, only a few medical facilities use gonadal shields. In addition, the contribution of internal scatter to the gonadal dose should be considered because it is unavoidable. Therefore, this study aimed to investigate the effectiveness of the gonad shield according to its thickness and to evaluate the internal scatter contribution during the rectal radiotherapy. First, a Monte Carlo simulation was performed using a simplified patient phantom that consisted of the patient's body and gonad. The dose to the gonad was assessed according to the thickness of the gonad shield, beam direction, and the distance between the gonad and irradiation field. The internal scatter contribution was calculated as the ratio of the gonadal doses with and without a shield. Second, a mesh-type reference computational phantom (MRCP) was employed to calculate the internal scatter contribution to the gonadal dose in rectal radiotherapy. Subsequently, the contribution of internal scatter was investigated by analyzing the dosimetry results in actual patient cases. The gonad shield reduced 50-75% of the gonadal dose according to its thickness from 0.5-3 cm. The internal scatter contribution ranged from 55-65% for the simplified phantom, whereas it was 75% on average for MRCP. The dosimetry results from the clinical case were similar to those of both the simplified phantom and MRCP, that is, the internal scatter contribution varied from 55-77% in most cases. These results are expected to improve the accuracy of rectal radiotherapy and benefit radiation shielding of the gonads.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143655597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intelligent progress monitoring of healing wound tissues based on classification models.","authors":"Imen Fourati Kallel, Jalila Kaouthar Kammoun, Hanen Lajnef, Saif Ben Ali","doi":"10.1088/2057-1976/adc137","DOIUrl":"10.1088/2057-1976/adc137","url":null,"abstract":"<p><p>The evolution of wound monitoring techniques has seen a significant shift from traditional methods like ruler-based measurements to the use of AI-assisted assessment of wound tissues. This progression has been driven by the need for more accurate, efficient, and non-invasive methods for wound assessment and treatment planning. The proposed approach aims to automate wound analysis and reduce efforts to manage chronic wounds. The snake's approach is used to extract wound areas and geometrical measures are used to monitor the rate of wound healing. A segmentation based on the color thresholding and K-means technique was carried out and demonstrated the effectiveness of the thresholding technique in mapping the wound tissues. The three proportions of wound tissues necrosis, slough, granulation and wound size are combined with three features from the patient's medical record and transmitted to the Support Vector Machine (SVM), Naive Bayes (NB) and Decision Tree (DT) classifiers. Finally, this work is ended with a comparative study that shows the efficiency and the interest of the proposed approach.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143647113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alterations in functional connectivity of the brain during postural balance maintenance with auditory stimuli: a stabilometry and electroencephalogram study.","authors":"Lyubov Oknina, Ekaterina Strelnikova, Li-Fong Lin, Margarita Kashirina, Andrey Slezkin, Vladimir Zakharov","doi":"10.1088/2057-1976/adbf26","DOIUrl":"10.1088/2057-1976/adbf26","url":null,"abstract":"<p><p><i>Objectives.</i>In daily life, individuals continuously integrate motor and cognitive tasks, a process that is made possible by multisensory integration within the brain. Despite its importance, the neurophysiological mechanisms underlying the integration of stimuli from different sensory modalities remain unclear. The objective of this study was to investigate the characteristics of functional connectivity (FC) in healthy adults during a balance task with additional auditory stimuli.<i>Material</i>s<i>& Methods.</i>This study involved the simultaneous recording of stabilometry and electroencephalogram (EEG) in 17 healthy volunteers. The experimental design included two tasks. In the first task, participants were required to maintain their center of pressure on a stabilometric platform while receiving visual feedback on body position (VBF). In the second task, participants performed the same task but with the addition of auditory stimuli in the form of music (VBF+MUSIC). The FCs values of EEG signals were analyzed using the coherence method.<i>Results.</i>Analysis of the stabilometric data revealed that the most significant differences between the tasks were observed in the dynamic indicators related to the maintenance of the vertical body position. The values of the Quality of the balance function decreased with the expected increase in the cognitive load. EEG analysis showed that the value of functional connectivity (FC) was lower in VBF+MUSIC compared to VBF. Significant difference of FCs was detected between the right primary auditory cortex and associative auditory cortex involved in delta and theta rhythms that may reflect difference in auditory data processing, whereas differences in alpha and beta rhythms were found in the parietal region, which may reflect different level of attention.<i>Conclusion.</i>This study demonstrated that the presence of auditory stimuli leads to changes in postural balance indicators that specifically reflect oscillations in the sagittal plane. These findings suggest multiple neurophysiological levels of postural control in multisensory environments.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143603841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling charge collection in silicon pixel detectors for proton therapy applications.","authors":"Alexander Schilling, Max Aehle, Johan Alme, Gergely Gábor Barnaföldi, Gábor Bíró, Tea Bodova, Vyacheslav Borshchov, Anthony van den Brink, Viljar Eikeland, Gregory Feofilov, Christoph Garth, Nicolas R Gauger, Ola Grøttvik, Håvard Helstrup, Sergey Igolkin, Jacob G Johansen, Ralf Keidel, Chinorat Kobdaj, Tobias Kortus, Viktor Leonhardt, Shruti Mehendale, Raju Ningappa Mulawade, Odd Harald Odland, George O'Neill, Gábor Papp, Thomas Peitzmann, Helge Egil Seime Pettersen, Pierluigi Piersimoni, Maksym Protsenko, Max Rauch, Attiq Ur Rehman, Matthias Richter, Dieter Röhrich, Joshua Santana, Joao Seco, Arnon Songmoolnak, Ákos Sudár, Ganesh Tambave, Ihor Tymchuk, Kjetil Ullaland, Monika Varga-Kofarago, Boris Wagner, RenZheng Xiao, Shiming Yang","doi":"10.1088/2057-1976/adbf9c","DOIUrl":"10.1088/2057-1976/adbf9c","url":null,"abstract":"<p><p><i>Objective.</i>Monolithic active pixel sensors are used for charged particle tracking in many applications, from medical physics to astrophysics. The Bergen pCT collaboration designed a sampling calorimeter for proton computed tomography, based entirely on the ALICE PIxel DEtector (ALPIDE). The same telescope can be used for in-situ range verification in particle therapy. An accurate charge diffusion model is required to convert the deposited energy from Monte Carlo simulations to a cluster of pixels, and to estimate the deposited energy, given an experimentally observed cluster.<i>Approach.</i>We optimize the parameters of different charge diffusion models to experimental data for both proton computed tomography and proton range verification, collected at the Danish Centre for Particle Therapy. We then evaluate the performance of downstream tasks to investigate the impact of charge diffusion modeling.<i>Main results.</i>We find that it is beneficial to optimize application-specific models, with a power law working best for proton computed tomography, and a model based on a 2D Cauchy-Lorentz distribution giving better agreement for range verification. We further highlight the importance of evaluating the downstream tasks with multiple approaches to obtain a range of expected performance metrics for the application.<i>Significance.</i>This work demonstrates the influence of the charge diffusion model on downstream tasks, and recommends a new model for proton range verification with an ALPIDE-based pixel telescope.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143613218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel multiple focal point technique for laser-induced shear wave generation in deep tissue: simulation insights.","authors":"Reza Bahrami Gorji, Mohammad Mohammadi, Bahador Makkiabadi","doi":"10.1088/2057-1976/adb755","DOIUrl":"10.1088/2057-1976/adb755","url":null,"abstract":"<p><p><i>Purpose</i>. Laser applications in biomedical imaging have several decades of history; however, some unexplored corners remain for study. While previous studies contain massive data on photoacoustic imaging, optical coherence imaging/elastography, and surface acoustic waves, the generation of shear waves in bulk by laser remained rarely investigated. Here, we study the applicability of multipoint laser exposure to generate deep tissue shear waves, which have potential applications in dynamic elastography.<i>Method</i>. Previous studies used single shots of laser to induce shear waves and create weak waves. Based on this, we suggest a multipoint approach to enhancing the amplitude of the shear wave in bulk. These approaches contain supersonic exposure, overlay Mach 1, and comb-push exposure in a finite element simulation environment.<i>Result</i>. Although the results showed a linear relationship between laser power and shear wave amplitude, the supersonic and overlay exposure increased the amplitude from 15 nm to over 60 nm and 230 nm, respectively.<i>Conclusion</i>. Our approaches showed a potentially successful increase in shear wave amplitude in the simulation environment. However, experimental data still need to be investigated before these techniques can be suggested for laser-induced shear wave elastography in the deep medium.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143447645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational modeling of neuromuscular activation by transcutaneous electrical nerve stimulation to the lower back.","authors":"Mohigul Nasimova, Niranjan Khadka, Marom Bikson","doi":"10.1088/2057-1976/adbf9d","DOIUrl":"10.1088/2057-1976/adbf9d","url":null,"abstract":"<p><p><i>Objectives.</i>Transcutaneous Electrical Nerve Stimulation (TENS) to the lower back is an established electrical therapy for acute and chronic back pain. The efficacy and mechanisms of lower back TENS depend on the penetration depth of electrical current. We compare the intensity and spatial extent (depth) of current flow in the body during TENS with varied electrode positions/shapes on the human back.<i>Materials and Methods.</i>A high-resolution MRI-derived anatomical model of the back was developed, considering major tissue compartments, including skin and muscles. TENS with upper and lower back electrode positions and varied electrode shapes (square, circular, rectangular) were simulated. An exemplary 50 mA current was applied under quasistatic approximation and quasi-uniform electric field assumption of 6.15 V m^-1(low), 12.3 V m^-1(mid), and 24.6 V m^-1(high) neuromuscular activation thresholds were considered.<i>Results.</i>Under all simulated TENS conditions (50 mA), electric fields at the skin exceed the high threshold (consistent with peripheral nerve activation) and at least some muscle regions exceed the mid threshold. Muscle activation was influenced by the anatomy of muscle in the medial-lateral direction and upper-lower back. The electrode shape had minimal effect on deep tissue current penetration.<i>Conclusions.</i>Our simulations indicate significant current penetration into back tissue (electric fields above low threshold) to >8 cm in all TENS conditions simulated, consistent with nerve and muscle activation.<i>Significance.</i>Anatomically precise models of upper and lower back TENS show current penetration to deep muscle, supporting direct muscle stimulation driving clinical benefits.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143613215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An investigation of pre-stimulus eeg for prediction of driver reaction time.","authors":"Shams Ur Rahman, Noel O'Connor, Joe Lemley, Graham Healy","doi":"10.1088/2057-1976/adbf25","DOIUrl":"10.1088/2057-1976/adbf25","url":null,"abstract":"<p><p>Driver drowsiness significantly contributes to road accidents worldwide, and timely prediction of driver reaction time is crucial for developing effective advanced driver assistance systems. In this paper, we present an EEG-based prediction framework that investigates the impact of different pre-stimulus time windows, frequency band combinations, and channel groups for driver reaction time estimation using data from a 90-minute sustained attention driving task. Our systematic evaluation using a publicly available dataset of 25 drivers [1] reveals that a 2-s pre-stimulus window yields the lowest prediction error. Notably, our proposed 1D Convolutional Neural Network (CNN) approach reduces the Mean Absolute Error (MAE) by nearly 30% (from 0.51sec to 0.36 sec for the alpha band) compared to classical machine learning models. Moreover, while individual frequency bands (e.g., alpha and theta) outperform combined band approaches, most spatial channel groups deliver similar performance to the full 32-channel configuration-with the exception of frontal channels. These improvements underscore the potential for real-world applications in reducing road accidents by enabling timely interventions based on predictive analytics.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143603842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A facebow-free technique for mechanical articulator remounting using computed tomography.","authors":"Yu-Ching Hsiao, Chen-Jung Chang, Te-Yu Lin, Jing-Jing Fang","doi":"10.1088/2057-1976/adbdd4","DOIUrl":"10.1088/2057-1976/adbdd4","url":null,"abstract":"<p><p>This technical note introduces a technique for remounting dental casts to a mechanical articulator using computed tomography (CT) without a facebow. We have developed a jig method that ensures precise remounting by aligning the virtual dental casts to the upper and lower jaw models reconstructed from the CT and transferring them to a virtual articulator based on anatomical landmarks. A custom-designed positioning jig and splint further enhance the accuracy of the process, preserving the spatial relationship between the midface and mandible. The proposed mounting jig technique can help transfer the patient's maxillomandibular relationship quickly, repeatedly, and accurately to an articulator after the patient leaves.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143575685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Architectural order identification across label-free living cell imaging with a swin transformer-conditional GAN.","authors":"Shitou Liu, Guocheng Sun, Xi Liu, Qianjin Guo","doi":"10.1088/2057-1976/adbdd5","DOIUrl":"10.1088/2057-1976/adbdd5","url":null,"abstract":"<p><p>Quantitative Label-Free Imaging Phase and Polarization (QLIPP) technology enables non-invasive analysis and characterization of samples based on their intrinsic properties, without the need for exogenous labeling or contrast agents. However, QLIPP often involves dealing with complex tissue structures, such as overlapping or interconnected regions, making it challenging to accurately depict such intricate architectures. In order to elucidate the inherent ordered structures across spatial and temporal scales in living systems, we propose an efficient architecture based on the Swin Transformer Conditional Generative Adversarial Network (ST-cGAN). This model synergistically combines polarized light microscopy and the cooperative reconstruction of complementary optical properties. Leveraging complementary contrast information, the ST-cGAN achieves high-precision predictions of specific structures, addressing the difficulty of QLIPP in portraying complex tissue structures accurately. We demonstrate the efficacy of the model by predicting ordered structures within different components of kidney tissue morphology, including F-actin and cell nuclei. To enhance the accessibility and reproducibility of our proposed method, the open-source code used for neural network training is available on GitHub. This work marks a significant advancement in the field of label-free live cell imaging, particularly in the identification of ordered structures, contributing to a deeper understanding of dynamic biological processes.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143575686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}