{"title":"Classification of Motor Imagery Tasks Using EEG Based on Wavelet Scattering Transform and Convolutional Neural Network","authors":"Rantu Buragohain;Jejariya Ajaybhai;Karan Nathwani;Vinayak Abrol","doi":"10.1109/LSENS.2024.3488356","DOIUrl":"https://doi.org/10.1109/LSENS.2024.3488356","url":null,"abstract":"Electroencephalogram (EEG) signal classification is of utmost importance in brain-computer interface (BCI) systems. However, the inherent complex properties of EEG signals pose a challenge in their analysis and modeling. This letter proposes a novel approach of integrating wavelet scattering transform (WST) with convolutional neural network (CNN) for classifying motor imagery (MI) via EEG signals (referred as WST-CNN), capable of extracting distinctive characteristics in signals even when the data is limited. In this architecture, the first layer is nontrainable WST features with fixed initializations in WST-CNN. Furthermore, WSTs are robust to local perturbations in data, especially in the form of translation invariance, and resilient to deformations, thereby enhancing the network's reliability. The performance of the proposed idea is evaluated on the DBCIE dataset for three different scenarios: left-arm (LA) movement, right-arm (RA) movement, and simultaneous movement of both arms (BA). The BCI Competition IV-2a dataset was also employed to validate the proposed concept across four distinct MI tasks, such as movements in: left-hand (LH), right-hand (RH), feet (FT), and tongue (T). The classifications' performance was evaluated in terms of accuracy (\u0000<inline-formula><tex-math>$eta$</tex-math></inline-formula>\u0000), sensitivity (\u0000<inline-formula><tex-math>$S_{e}$</tex-math></inline-formula>\u0000), specificity (\u0000<inline-formula><tex-math>$S_{p}$</tex-math></inline-formula>\u0000), and weighted F1-score, which reached up to 92.72%, 92.72%, 97.57%, and 92.75% for classifying LH, RH, FT, and T on the BCI Competition IV-2a dataset and 89.19%, 89.19%, 94.60%, and 89.33% for classifying LA, RA, and BA, on the DBCIE dataset, respectively.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"8 12","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142636262","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}
Winston Doss Marveldoss;Bandaru Joshika;Bijo Sebastian
{"title":"Tracking and Estimation Approach for Human-Aware Mobile Robot Navigation","authors":"Winston Doss Marveldoss;Bandaru Joshika;Bijo Sebastian","doi":"10.1109/LSENS.2024.3492373","DOIUrl":"https://doi.org/10.1109/LSENS.2024.3492373","url":null,"abstract":"Accurate perception of the environment, including the detection and tracking of humans, is essential for safe navigation of mobile robots in human-centric environments. Existing State-of-the-Art techniques rely on high-performance sensors. This leads to expensive robotic systems, which limits the large-scale deployment of autonomous mobile robots in social spaces. In this letter, we propose and validate a novel human tracking and estimation approach that relies on a low-cost 2-D LiDAR and a monocular camera. The proposed approach leverages the capabilities of each sensor by relying on the camera for human detection and the LiDAR for human pose estimation. Precise calibration and registration of the sensor frames allow for data association in the presence of multiple human targets. Human detection and pose estimation data from the sensor suite are used as measurement by an extended Kalman filter, which allows for effective tracking over multiple frames, even in the presence of occlusion. The overall approach addresses the limitations of each individual sensor without increasing the overall cost of the sensor suite. Tracking and estimation performance for the proposed approach was evaluated on experimental trails in real-world conditions with artificial markers as ground truth for each human target. The results demonstrate satisfactory performance for the proposed approach to be used in human-aware autonomous navigation in real-world settings.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"8 12","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679324","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 and Characterizing an Impedance-Type Micro Flow Sensor With Pulse Excitation","authors":"Wei Xu;Wenlin Xiao;Ke Xiao","doi":"10.1109/LSENS.2024.3490983","DOIUrl":"https://doi.org/10.1109/LSENS.2024.3490983","url":null,"abstract":"This letter presents the modeling and characterization of a pulse-excited micro thermal flow sensor based on electrochemical impedance sensing. The proposed transient model reveals that the sensor output, measured as the impedance slope under pulse excitation, is almost one order of magnitude stronger at the downstream electrodes, as compared to the upstream pair. Consequently, the micro-electromechanical systems (MEMS) flow sensor is designed with an 8-μm-thick flexible structure and a 1.4 mm distance between the microheater and downstream electrodes. Testing results show that the fabricated impedance-type micro flow sensor achieves a maximum sensitivity of 8.9 (mΩ/s)/(μm/s) for the 1X PBS flow, while consuming less than 15.8 mW of heating power with a fluid flow up to 750 μm/s. Furthermore, the proposed theoretical model closely aligns with experimental results, confirming its potential as a valuable tool for optimizing impedance-type flow sensors that utilize pulse heating strategies to detect extremely low fluid flow in the future.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"8 12","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672107","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":"Investigation of Surface Affinity and Desorption Kinetics of Mixture of Volatile Organic Compounds on CuO-Based Resistive Gas Sensors","authors":"Saraswati Kulkarni;Ruma Ghosh","doi":"10.1109/LSENS.2024.3490837","DOIUrl":"https://doi.org/10.1109/LSENS.2024.3490837","url":null,"abstract":"Analysis and understanding of the mixture of volatile organic compound (VOC) sensing are crucial for the development of sensors in conditions closer to real-life applications, such as health care, air quality monitoring, industrial safety, etc. In this study, we investigated the response dynamics of CuO-nanomaterial-based resistive sensors to 25–75 ppm of individual, binary, ternary, and quaternary mixtures of five VOCs—acetone, acetonitrile, isopropanol, methanol, and toluene at 300 °C. The CuO exhibited responses equal to the sum of its steady-state responses to individual VOCs for all the possible combinations of binary and ternary mixtures with 25 ppm of the constituent gases. A systematic study based on the recovery cycle was conducted by retracting the VOCs sequentially from the proximity of CuO surface after recording response cycle. Interestingly, the recovery time constant τ\u0000<sub>rec</sub>\u0000 was found to follow the order—isopropanol (96.93 – 435.45) ≥ methanol (111.82 – 313.21) > toluene (9.9 – 220.49) > acetonitrile (85.96 – 332.32) > acetone (could not be found) in all binary, ternary, and quaternary mixtures of VOCs, irrespective of the sequence of retraction of the VOCs from the mixture. Also, it was found that VOCs with –OH groups have higher adsorption capacity on the sensing layer as compared to –NH\u0000<sub>2</sub>\u0000, – C = O, and aromatic VOCs.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"8 12","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672206","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 Comparative Study on Synergy Between Energy Harvesting and Pressure Sensing in Piezotronic Heterojunctions","authors":"Zihao Liang;Emad Iranmanesh;Shuxin Lin;Weipeng Xuan;Hang Zhou","doi":"10.1109/LSENS.2024.3491581","DOIUrl":"https://doi.org/10.1109/LSENS.2024.3491581","url":null,"abstract":"In this letter, a novel fully flexible piezotronic bipolar junction transistor (n-p-n PBJT) is designed and constructed by configuring two ZnO/Poly(3-hexylthiophene) heterojunction diodes back to back. The n-p-n PBJT acts as a signal-mediated device providing both current and voltage as the outputs. The utilization of the n-p-n PBJT in wearable applications is testified where a unique synergy between energy harvesting and sensing is found. Under mechanical stress, the output signal is amplified (with no preamplifier circuitry), which makes it a proper candidate as a high-performance sensor (voltage-based sensitivity is extracted as 0.49 V/kPa, four times higher than piezotronic p-n heterojunction). As a wearable energy harvester, the output signal is rectified (with no signal regulation circuitry), and it generates a peak output power of 2.9 µW, which is ten times higher than that of the piezotronic p-n diode. The outstanding performance of the n-p-n PBJT provides a new strategy to improve device performance for the emerging application in wearable electronics.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"8 12","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679315","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}
Qihao Zeng;Mingkun Wang;Yupeng Zhang;Hongyi Lin;Wei Qiao;Dong Sun
{"title":"Optical Path Difference Modulation Method Based on the Kerr Effect","authors":"Qihao Zeng;Mingkun Wang;Yupeng Zhang;Hongyi Lin;Wei Qiao;Dong Sun","doi":"10.1109/LSENS.2024.3490658","DOIUrl":"https://doi.org/10.1109/LSENS.2024.3490658","url":null,"abstract":"Optical path difference is commonly used to adjust the signal of coherent light. Current optical systems typically adjust the transmission distance of the beam or the refractive index of the medium to change the optical path. However, the former approach often involves complex operations, risks of mechanical damage, and difficulties in adjustment, while the latter has a limited adjustment range. This letter proposes a Kerr-fiber-based optical path difference adjustment system. In this system, the Kerr liquid inside the fiber induces a change in birefringence due to the electric field's polarization effect, enabling rapid optical path adjustment. The system adjusts the effective refractive index by applying an external voltage: a 10-V voltage induces a one-cycle change in interference fringes, and increasing the voltage to 50 V results in a 0.1 change in the refractive index, with a minimum adjustment precision of 0.01. Experimental results demonstrate a millisecond-level response rate for the overall system. Comparative tests show that this method is similar to classic adjustment methods but offers simplified operation. In addition, the system exhibits enhanced stability in scenarios requiring rapid and precise adjustments.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"8 12","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672011","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}
Jair A.Lima Silva;Wesley Costa;Khan Md Mazedul Islam;Jan Kleine Deters;Ewout Bergsma;Helder R. Oliveira Rocha;Patrick Noordhoek;Heinrich Wörtche
{"title":"Improving the Power Consumption of Thread Mesh Networks Through Genetic Algorithm Optimization","authors":"Jair A.Lima Silva;Wesley Costa;Khan Md Mazedul Islam;Jan Kleine Deters;Ewout Bergsma;Helder R. Oliveira Rocha;Patrick Noordhoek;Heinrich Wörtche","doi":"10.1109/LSENS.2024.3488652","DOIUrl":"https://doi.org/10.1109/LSENS.2024.3488652","url":null,"abstract":"Reliability is a constraint of low-power wireless connectivity, commonly addressed by the deployment of mesh topology. Accordingly, power consumption becomes a major concern during the design and implementation of such networks. Thus, a mono-objective optimization was implemented in this work to decrease the total amount of power consumed by a low-power wireless mesh network based on Thread protocol. Using a genetic algorithm, the optimization procedure takes into account a predefined connectivity matrix, in which the possible distances between all network devices are considered. The experimental proof-of-concept shows that a mean gain of 26.45 dB is achievable in a specific scenario. Through our experimental results, we conclude that the Thread mesh protocol has much leeway to meet the low-power consumption requirement of wireless sensor networks.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"8 12","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679323","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}
Hao Jia;Pere Marti-Puig;Cesar F Caiafa;Moises Serra-Serra;Zhe Sun;Jordi Solé-Casals
{"title":"Exploring Tensor Completion for Missing Data Estimation in Wind Farms","authors":"Hao Jia;Pere Marti-Puig;Cesar F Caiafa;Moises Serra-Serra;Zhe Sun;Jordi Solé-Casals","doi":"10.1109/LSENS.2024.3488560","DOIUrl":"https://doi.org/10.1109/LSENS.2024.3488560","url":null,"abstract":"The large number of greenhouse gas emissions caused by human activities, and their harmful effect on the earth’s climate, have reached a point where actions are needed. Wind energy is one of the available green energies that can be used to mitigate this problem. Predictive maintenance is of vital importance to ensure continuous wind power generation and is typically based on the use of sensor data from all wind turbine systems. But in some cases, data contain outliers or are not available at all due to sensor or system failures. In this letter, we explore the use of tensor completion methods to estimate missing data in this field. Experimental results demonstrate the usefulness of the proposed tensor completion algorithms, especially the high-accuracy low-rank tensor completion (HaLRTC) method, which outperforms the interpolation method used as a reference.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"8 12","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672008","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}