11 pages, 2431 KiB  
Article
Low Latency and High Data Rate (LLHD) Scheduler: A Multipath TCP Scheduler for Dynamic and Heterogeneous Networks
by Tabassum Lubna 1, Imtiaz Mahmud 2 and You-Ze Cho 1,*
1 School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
2 Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
Sensors 2022, 22(24), 9869; https://doi.org/10.3390/s22249869 - 15 Dec 2022
Cited by 3 | Viewed by 2633
Abstract
The scheduler is a crucial component of the multipath transmission control protocol (MPTCP) that dictates the path that a data packet takes. Schedulers are in charge of delivering data packets in the right order to prevent delays caused by head-of-line blocking. The modern [...] Read more.
The scheduler is a crucial component of the multipath transmission control protocol (MPTCP) that dictates the path that a data packet takes. Schedulers are in charge of delivering data packets in the right order to prevent delays caused by head-of-line blocking. The modern Internet is a complicated network whose characteristics change in real-time. MPTCP schedulers are supposed to understand the real-time properties of the underlying network, such as latency, path loss, and capacity, in order to make appropriate scheduling decisions. However, the present scheduler does not take into account all of these characteristics together, resulting in lower performance. We present the low latency and high data rate (LLHD) scheduler, which successfully makes scheduling decisions based on real-time information on latency, path loss, and capacity, and achieves around 25% higher throughput and 45% lower data transmission delay than Linux’s default MPTCP scheduler. Full article
(This article belongs to the Section Communications)
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22 pages, 5874 KiB  
Article
A Comparative Study on a Novel Quality Assessment Protocol Based on Image Analysis Methods for Color Doppler Ultrasound Diagnostic Systems
by Giorgia Fiori 1, Andrada Pica 2, Salvatore Andrea Sciuto 1, Franco Marinozzi 2, Fabiano Bini 2,* and Andrea Scorza 1
1 Department of Industrial, Electronic and Mechanical Engineering, University of Roma Tre, 00146 Rome, Italy
2 Department of Mechanical and Aerospace Engineering, “Sapienza” University of Rome, 00184 Rome, Italy
Sensors 2022, 22(24), 9868; https://doi.org/10.3390/s22249868 - 15 Dec 2022
Cited by 9 | Viewed by 2786
Abstract
Color Doppler (CD) imaging is widely used in diagnostics since it allows real-time detection and display of blood flow superimposed on the B-mode image. Nevertheless, to date, a shared worldwide standard on Doppler equipment testing is still lacking. In this context, the study [...] Read more.
Color Doppler (CD) imaging is widely used in diagnostics since it allows real-time detection and display of blood flow superimposed on the B-mode image. Nevertheless, to date, a shared worldwide standard on Doppler equipment testing is still lacking. In this context, the study herein proposed would give a contribution focusing on the combination of five test parameters to be included in a novel Quality Assessment (QA) protocol for CD systems testing. A first approach involving the use of the Kiviat diagram was investigated, assuming the diagram area, normalized with respect to one of the gold standards, as an index of the overall Doppler system performance. The QA parameters were obtained from the post-processing of CD data through the implementation of custom-written image analysis methods and procedures, here applied to three brand-new high-technology-level ultrasound systems. Experimental data were collected through phased and convex array probes, in two configuration settings, by means of a Doppler flow phantom set at different flow rate regimes. The outcomes confirmed that the Kiviat diagram might be a promising tool applied to quality controls of Doppler equipment, although further investigations should be performed to assess the sensitivity and specificity of the proposed approach. Full article
(This article belongs to the Special Issue Advances in Biomedical Sensing, Instrumentation and Systems)
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12 pages, 3188 KiB  
Communication
A Reinforcement Learning-Based Strategy of Path Following for Snake Robots with an Onboard Camera
by Lixing Liu, Xian Guo * and Yongchun Fang
Institute of Robotics and Automatic Information System, College of Artificial Intelligence, Nankai University, Tianjin 300071, China
Sensors 2022, 22(24), 9867; https://doi.org/10.3390/s22249867 - 15 Dec 2022
Cited by 5 | Viewed by 2859
Abstract
For path following of snake robots, many model-based controllers have demonstrated strong tracking abilities. However, a satisfactory performance often relies on precise modelling and simplified assumptions. In addition, visual perception is also essential for autonomous closed-loop control, which renders the path following of [...] Read more.
For path following of snake robots, many model-based controllers have demonstrated strong tracking abilities. However, a satisfactory performance often relies on precise modelling and simplified assumptions. In addition, visual perception is also essential for autonomous closed-loop control, which renders the path following of snake robots even more challenging. Hence, a novel reinforcement learning-based hierarchical control framework is designed to enable a snake robot with an onboard camera to realize autonomous self-localization and path following. Specifically, firstly, a path following policy is trained in a hierarchical manner, in which the RL algorithm and gait knowledge are well combined. On this basis, the training efficiency is sufficiently optimized, and the path following performance of the control policy is greatly improved, which can then be implemented on a practical snake robot without any additional training. Subsequently, in order to promote visual self-localization during path following, a visual localization stabilization item is added to the reward function that trains the path following strategy, which endows a snake robot with smooth steering ability during locomotion, thereby guaranteeing the accuracy of visual localization and facilitating practical applications. Comparative simulations and experimental results are illustrated to exhibit the superior performance of the proposed hierarchical path following the control method in terms of convergence speed and tracking accuracy. Full article
(This article belongs to the Special Issue Sensors for Robots II)
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22 pages, 8615 KiB  
Article
Adaptive Data Transmission Algorithm for the System of Inertial Sensors for Hand Movement Acquisition
by Michał Pielka, Paweł Janik *, Małgorzata A. Janik and Zygmunt Wróbel
Faculty of Science and Technology, Institute of Biomedical Engineering, University of Silesia in Katowice, ul. Będzińska 39, 41-200 Sosnowiec, Poland
Sensors 2022, 22(24), 9866; https://doi.org/10.3390/s22249866 - 15 Dec 2022
Viewed by 1916
Abstract
Modern systems of intelligent sensors commonly use radio data transmission. Hand movement acquisition with the use of inertial sensors requires the processing and transmission of a relatively large amount of data, which may be associated with a significant load on the network structure. [...] Read more.
Modern systems of intelligent sensors commonly use radio data transmission. Hand movement acquisition with the use of inertial sensors requires the processing and transmission of a relatively large amount of data, which may be associated with a significant load on the network structure. Network traffic limitation, without losing the quality of monitoring parameters from the sensor system, is therefore important for the functioning of the radio network which integrates both the teletransmission sensor system and the data acquisition server. The paper presents a wearable solution for hand movement acquisition, which uses data transmission in the Wi-Fi standard and contains 16 MEMS (Micro Electro Mechanical System) sensors. An adaptive algorithm to control radio data transmission for the sensor system has been proposed. The algorithm implemented in the embedded system controls the change of the frame length, the length of the transmission frame and the frequency of its sending, which reduces the load on the network router. The use of the algorithm makes it possible to reduce the power consumption by the sensor system by up to 19.9% and to limit the number of data transferred by up to about 91.6%, without losing the quality of the monitored signal. The data analysis showed no statistically significant differences (p > 0.05) between the signal reconstructed from the complete data and processed by the algorithm. Full article
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14 pages, 8724 KiB  
Article
Proposal of a Real-Time Test Platform for Tactile Internet Systems
by Pedro V. A. Alves 1,†, Patricia D. M. Plentz 2 and Marcelo A. C. Fernandes 1,3,*,†
1 Laboratory of Machine Learning and Intelligent Instrumentation, Federal University of Rio Grande do Norte, Natal 59078-970, Brazil
2 Graduate Program of Computer Science, Federal University of Santa Catarina, Florianópolis 88036-610, Brazil
3 Department of Computer Engineering and Automation, Federal University of Rio Grande do Norte, Natal 59078-970, Brazil
These authors contributed equally to this work.
Sensors 2022, 22(24), 9865; https://doi.org/10.3390/s22249865 - 15 Dec 2022
Cited by 3 | Viewed by 2032
Abstract
This work aimed to develop a real-time test platform for systems associated with the tactile internet area. The proposal comprises a master device, a communication channel and a slave device. The master device is a tactile glove (wearable technology) that works as a [...] Read more.
This work aimed to develop a real-time test platform for systems associated with the tactile internet area. The proposal comprises a master device, a communication channel and a slave device. The master device is a tactile glove (wearable technology) that works as a tactile interface based on vibratory feedback. The master device can interact with virtual elements (local or remote). The Matlab/Simulink environment and a robotics toolbox form the communication channel and the slave device. The communication channel introduces a bidirectional connection of variable latency, and the slave device is defined as a robotic phantom omni manipulator emulated in Matlab/Simulink. The virtual robotic manipulator, the slave device, can generate different types of tactile sensations in the tactile glove, that is, in the master device. The platform can model tactile sensations such as coarse roughness, fine roughness, smoothness, dripping and softness. The proposed platform presented adequate results and can be used to test various algorithms and methods correlated to the tactile internet. Full article
(This article belongs to the Special Issue Advances in Tactile Sensing and Robotic Grasping)
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10 pages, 2194 KiB  
Article
Application for Recognizing Sign Language Gestures Based on an Artificial Neural Network
by Kamil Kozyra 1, Karolina Trzyniec 2, Ernest Popardowski 1,* and Maria Stachurska 3
1 Ailleron SA, Jana Pawła II 43b, 31-864 Krakow, Poland
2 Department of Machinery Exploitation, Ergonomics and Production Processes, University of Agriculture in Krakow, Balicka 116B, 30-149 Krakow, Poland
3 Institute of Safety and Quality Engineering, Faculty of Management Engineering, Poznań University of Technology, J. Rychlewskiego 2, 60-965 Poznan, Poland
Sensors 2022, 22(24), 9864; https://doi.org/10.3390/s22249864 - 15 Dec 2022
Cited by 4 | Viewed by 4228
Abstract
This paper presents the development and implementation of an application that recognizes American Sign Language signs with the use of deep learning algorithms based on convolutional neural network architectures. The project implementation includes the development of a training set, the preparation of a [...] Read more.
This paper presents the development and implementation of an application that recognizes American Sign Language signs with the use of deep learning algorithms based on convolutional neural network architectures. The project implementation includes the development of a training set, the preparation of a module that converts photos to a form readable by the artificial neural network, the selection of the appropriate neural network architecture and the development of the model. The neural network undergoes a learning process, and its results are verified accordingly. An internet application that allows recognition of sign language based on a sign from any photo taken by the user is implemented, and its results are analyzed. The network effectiveness ratio reaches 99% for the training set. Nevertheless, conclusions and recommendations are formulated to improve the operation of the application. Full article
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14 pages, 3968 KiB  
Article
Self-Sensing Antenna for Soil Moisture: Beacon Approach
by Maja Škiljo, Zoran Blažević *, Lea Dujić-Rodić, Toni Perković and Petar Šolić
Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture in Split, University of Split, 21000 Split, Croatia
Sensors 2022, 22(24), 9863; https://doi.org/10.3390/s22249863 - 15 Dec 2022
Cited by 8 | Viewed by 4117
Abstract
On the way from the Internet of things (IoT) to the Internet of underground things (IoUT) the main challenge is antenna design. The enabling technologies still rely on simple design and low cost, but the systems are more complex. The LoRa-based system combined [...] Read more.
On the way from the Internet of things (IoT) to the Internet of underground things (IoUT) the main challenge is antenna design. The enabling technologies still rely on simple design and low cost, but the systems are more complex. The LoRa-based system combined with a machine learning approach can be used for the estimation of soil moisture by using signal strength data, but for the improvement of the system performance we propose the optimization of the antenna for underground use. The soil properties are frequency-dependent and varying in time, which may cause variations in the signal wavelength and input impedance of the antenna underground. Instead of using wideband antenna design or standard helical antenna provided in LoRa module, which are typical in the IoUT research community for communication links, we propose a narrow-band antenna design for the application in soil moisture sensing. It is shown that the approach of simply matching the antenna buried in dry sand can provide a substantial signal level difference, ranging from approximately 10 dB (achieved by proof-of-concept measurements) to as much as 40 dB (calculated by a full wave simulator) in reflection coefficient when the moisture content is being increased by 20%. This can ensure more reliable radio sensing in novel sensorless technology where soil moisture information is extracted from the signal strength of a transmitting device. Full article
(This article belongs to the Topic IOT, Communication and Engineering)
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12 pages, 2884 KiB  
Article
Towards a Practical Implementation of a Single-Beam All-Optical Non-Zero-Field Magnetic Sensor for Magnetoencephalographic Complexes
by Mikhail Petrenko and Anton Vershovskii *
Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
Sensors 2022, 22(24), 9862; https://doi.org/10.3390/s22249862 - 15 Dec 2022
Cited by 4 | Viewed by 1668
Abstract
We present a single-beam all-optical two-channel magnetic sensor scheme developed for biological applications such as non-zero-field magnetoencephalography and magnetocardiography. The pumping, excitation and detection of magnetic resonance in two cells are performed using a single laser beam with time-modulated linear polarization: the linear [...] Read more.
We present a single-beam all-optical two-channel magnetic sensor scheme developed for biological applications such as non-zero-field magnetoencephalography and magnetocardiography. The pumping, excitation and detection of magnetic resonance in two cells are performed using a single laser beam with time-modulated linear polarization: the linear polarization of the beam switches to orthogonal every half-cycle of the Larmor frequency. Light with such characteristics can be transmitted over a single-mode polarization-maintaining fiber without any loss in the quality of the polarization characteristics. We also present an algorithm for calculating optical elements in a sensor scheme, the results of measuring the parametric dependences of magnetic resonance in cells, and the results of direct testing of a sensor in a magnetic shield. We demonstrate sensitivity at the level of 20 fT/√Hz in one sensor channel in the frequency range of 80–200 Hz. Full article
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16 pages, 2744 KiB  
Article
Multi-Parameter Predictive Model of Mobile Robot’s Battery Discharge for Intelligent Mission Planning in Multi-Robot Systems
by Bartosz Poskart 1, Grzegorz Iskierka 1, Kamil Krot 1, Robert Burduk 2, Paweł Gwizdal 3 and Arkadiusz Gola 3,*
1 Faculty of Mechanical Engineering, Wrocław University of Science and Technology, ul. Łukasiewicza 5, 50-371 Wrocław, Poland
2 Faculty of Information and Communication Technology, Wrocław University of Science and Technology, ul. Z. Janiszewskiego 7, 50-372 Wrocław, Poland
3 Faculty of Mechanical Engineering, Lublin University of Technology, ul. Nadbystrzycka 36, 20-618 Lublin, Poland
Sensors 2022, 22(24), 9861; https://doi.org/10.3390/s22249861 - 15 Dec 2022
Cited by 8 | Viewed by 2809
Abstract
The commercially available battery management and mission scheduling systems for fleets of autonomous mobile robots use different algorithms to calculate the current state of charge of the robot’s battery. This information alone cannot be used to predict whether it will be possible for [...] Read more.
The commercially available battery management and mission scheduling systems for fleets of autonomous mobile robots use different algorithms to calculate the current state of charge of the robot’s battery. This information alone cannot be used to predict whether it will be possible for a single robot in the fleet to execute all of the scheduled missions. This paper provides insight into how to develop a universal battery discharge model based on key mission parameters, which allows for predicting the battery usage over the course of the scheduled missions and can, in turn, be used to determine which missions to delegate to other robots in the fleet, or if more robots are needed in the fleet to accomplish the production plan. The resulting model is, therefore, necessary for mission scheduling in a flexible production system, including autonomous mobile robot transportation networks. Full article
(This article belongs to the Special Issue Sensors and Fault-Tolerant Systems for Automated Guided Vehicles)
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20 pages, 2211 KiB  
Article
Data Integration from Heterogeneous Control Levels for the Purposes of Analysis within Industry 4.0 Concept
by Tibor Horak *, Peter Strelec, Michal Kebisek, Pavol Tanuska and Andrea Vaclavova
Institute of Applied Informatics, Automation and Mechatronics, Faculty of Materials Science and Technology in Trnava, Slovak University of Technology in Bratislava, 91724 Trnava, Slovakia
Sensors 2022, 22(24), 9860; https://doi.org/10.3390/s22249860 - 15 Dec 2022
Cited by 4 | Viewed by 3434
Abstract
Small- and medium-sized manufacturing companies must adapt their production processes more quickly. The speed with which enterprises can apply a change in the context of data integration and historicization affects their business. This article presents the possibilities of implementing the integration of control [...] Read more.
Small- and medium-sized manufacturing companies must adapt their production processes more quickly. The speed with which enterprises can apply a change in the context of data integration and historicization affects their business. This article presents the possibilities of implementing the integration of control processes using modern technologies that will enable the adaptation of production lines. Integration using an object-oriented approach is suitable for complex tasks. Another approach is data integration using the entity referred to as tagging (TAG). Tagging is essential to apply for fast adaptation and modification of the production process. The advantage is identification, easier modification, and generation of data structures where basic entities include attributes, topics, personalization, locale, and APIs. This research proposes a model for integrating manufacturing enterprise data from heterogeneous levels of management. As a result, the model and the design procedure for data integrating production lines can efficiently adapt production changes. Full article
(This article belongs to the Special Issue Sustainable IoT Solutions for Industrial Applications)
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15 pages, 5367 KiB  
Article
Explainable Artificial Intelligence Model for Stroke Prediction Using EEG Signal
by Mohammed Saidul Islam 1, Iqram Hussain 2,3,*, Md Mezbaur Rahman 1, Se Jin Park 4 and Md Azam Hossain 1,*
1 Network and Data Analysis Group, Department of Computer Science and Engineering, Islamic University and Technology (IUT), Gazipur 1704, Bangladesh
2 Department of Biomedical Engineering, Medical Research Center, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea
3 Data Mind Ltd., Dhaka 1230, Bangladesh
4 AI-Based Healthcare Research Group, Sewon Intelligence Ltd., Seoul 04512, Republic of Korea
Sensors 2022, 22(24), 9859; https://doi.org/10.3390/s22249859 - 15 Dec 2022
Cited by 117 | Viewed by 10115
Abstract
State-of-the-art healthcare technologies are incorporating advanced Artificial Intelligence (AI) models, allowing for rapid and easy disease diagnosis. However, most AI models are considered “black boxes,” because there is no explanation for the decisions made by these models. Users may find it challenging to [...] Read more.
State-of-the-art healthcare technologies are incorporating advanced Artificial Intelligence (AI) models, allowing for rapid and easy disease diagnosis. However, most AI models are considered “black boxes,” because there is no explanation for the decisions made by these models. Users may find it challenging to comprehend and interpret the results. Explainable AI (XAI) can explain the machine learning (ML) outputs and contribution of features in disease prediction models. Electroencephalography (EEG) is a potential predictive tool for understanding cortical impairment caused by an ischemic stroke and can be utilized for acute stroke prediction, neurologic prognosis, and post-stroke treatment. This study aims to utilize ML models to classify the ischemic stroke group and the healthy control group for acute stroke prediction in active states. Moreover, XAI tools (Eli5 and LIME) were utilized to explain the behavior of the model and determine the significant features that contribute to stroke prediction models. In this work, we studied 48 patients admitted to a hospital with acute ischemic stroke and 75 healthy adults who had no history of identified other neurological illnesses. EEG was obtained within three months following the onset of ischemic stroke symptoms using frontal, central, temporal, and occipital cortical electrodes (Fz, C1, T7, Oz). EEG data were collected in an active state (walking, working, and reading tasks). In the results of the ML approach, the Adaptive Gradient Boosting models showed around 80% accuracy for the classification of the control group and the stroke group. Eli5 and LIME were utilized to explain the behavior of the stroke prediction model and interpret the model locally around the prediction. The Eli5 and LIME interpretable models emphasized the spectral delta and theta features as local contributors to stroke prediction. From the findings of this explainable AI research, it is expected that the stroke-prediction XAI model will help with post-stroke treatment and recovery, as well as help healthcare professionals, make their diagnostic decisions more explainable. Full article
(This article belongs to the Section State-of-the-Art Sensors Technologies)
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24 pages, 2460 KiB  
Article
Analysis of Modern vs. Conventional Development Technologies in Transportation—The Case Study of a Last-Mile Delivery Process
by Mariusz Kostrzewski 1,*, Yahya Abdelatty 2, Ahmed Eliwa 3 and Mirosław Nader 1
1 Faculty of Transport, Warsaw University of Technology, 00-662 Warsaw, Poland
2 Independent Researcher, 31-323 Cracow, Poland
3 Doctoral School, Warsaw University of Technology, 00-661 Warsaw, Poland
Sensors 2022, 22(24), 9858; https://doi.org/10.3390/s22249858 - 15 Dec 2022
Cited by 18 | Viewed by 5640
Abstract
Transportation plays a significant role in the global economy and society and takes part in a lot of different processes such as mass transportation and the supply chain. Therefore, it is crucial to introduce modern technologies in this area of the economy in [...] Read more.
Transportation plays a significant role in the global economy and society and takes part in a lot of different processes such as mass transportation and the supply chain. Therefore, it is crucial to introduce modern technologies in this area of the economy in the context of Industry 4.0. The main scope of this study is to develop a model that supports analyzing last-mile logistics modern solutions using the latest technologies such as road autonomous delivery robots (RADRs), civil drones, or smart bikes, and compare them to conventional solutions (delivery vehicles). Multi-criteria decision analysis (MCDA) was applied to build a formal comparison model that scores the solutions and weights different criteria according to decision-makers and placeholders, to rank the solutions from the most crucial option to the weakest in a predetermined scenario with set parameters and conditions (three varied scenarios were included in the present investigation). The results of the model were in favor of using civil drones or smart bicycles to perform light deliveries in small urban areas (these key findings support the assumptions that are often manifested in speech in the context of the use of new technologies). The modern solutions scored almost 40–80% higher in total in the conglomeration of assessment criteria (such as safety, economy, laws and regulations, operation time for the delivery, environment, and payload) than the conventional solution, which indicates the importance of studying the implementation of such technologies. An interesting result of the study is the operational cost reduction by ca. 60–74% in favor of autonomous delivery robots, 89–93% in favor of civil delivery drones, and 87–90% in favor of smart bikes vs. conventional delivery trucks/vans. Yet, it should be underlined that the results may vary with different assumptions within the MCDA method. Full article
(This article belongs to the Collection Sensors and Sensing Technology for Industry 4.0)
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14 pages, 1737 KiB  
Communication
A Method for Estimating Longitudinal Change in Motor Skill from Individualized Functional-Connectivity Measures
by Nader Riahi 1, Ryan D’Arcy 1,2,3 and Carlo Menon 1,4,*
1 Schools of Engineering Science, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
2 DM Centre for Brain Health, Department of Radiology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
3 HealthTech Connex, Surrey, BC V3V 0E8, Canada
4 Biomedical and Mobile Health Technology Laboratory, Department of Health Sciences and Technology, ETH Zurich, 8008 Zurich, Switzerland
Sensors 2022, 22(24), 9857; https://doi.org/10.3390/s22249857 - 15 Dec 2022
Viewed by 1568
Abstract
Pragmatic, objective, and accurate motor assessment tools could facilitate more frequent appraisal of longitudinal change in motor function and subsequent development of personalized therapeutic strategies. Brain functional connectivity (FC) has shown promise as an objective neurophysiological measure for this purpose. The involvement of [...] Read more.
Pragmatic, objective, and accurate motor assessment tools could facilitate more frequent appraisal of longitudinal change in motor function and subsequent development of personalized therapeutic strategies. Brain functional connectivity (FC) has shown promise as an objective neurophysiological measure for this purpose. The involvement of different brain networks, along with differences across subjects due to age or existing capabilities, motivates an individualized approach towards the evaluation of FC. We advocate the use of EEG-based resting-state FC (rsFC) measures to address the pragmatic requirements. Pertaining to appraisal of accuracy, we suggest using the acquisition of motor skill by healthy individuals that could be quantified at small incremental change. Computer-based tracing tasks are a good candidate in this regard when using spatial error in tracing as an objective measure of skill. This work investigates the application of an individualized method that utilizes Partial Least Squares analysis to estimate the longitudinal change in tracing error from changes in rsFC. Longitudinal data from participants yielded an average accuracy of 98% (standard deviation of 1.2%) in estimating tracing error. The results show potential for an accurate individualized motor assessment tool that reduces the dependence on the expertise and availability of trained examiners, thereby facilitating more frequent appraisal of function and development of personalized training programs. Full article
(This article belongs to the Special Issue Sensors in Neurophysiology and Neurorehabilitation)
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15 pages, 4045 KiB  
Article
Validation of 2D Force Measurement Roller Ski and Practical Application
by Shuang Zhao 1,*, Vesa Linnamo 1, Keijo Ruotsalainen 1, Stefan Lindinger 2, Timo Kananen 3, Petri Koponen 3 and Olli Ohtonen 1
1 Faculty of Sport and Health Sciences, University of Jyväskylä, 40014 Jyväskylä, Finland
2 Center of Health and Performance (CHP), Department of Food and Nutrition and Sport Science, University of Gothenburg, 40530 Gothenburg, Sweden
3 Technical Research Centre of Finland, VTT MIKES, 87100 Kajaani, Finland
Sensors 2022, 22(24), 9856; https://doi.org/10.3390/s22249856 - 15 Dec 2022
Cited by 3 | Viewed by 3121
Abstract
Several methods could be used to measure the forces from skis or roller skis in cross-country skiing. Equipment that could measure medio-lateral forces may be of good help for investigating the relevant skating techniques. The aim of this study was to validate a [...] Read more.
Several methods could be used to measure the forces from skis or roller skis in cross-country skiing. Equipment that could measure medio-lateral forces may be of good help for investigating the relevant skating techniques. The aim of this study was to validate a pair of newly designed two-dimensional force measurement roller skis. The vertical and medio-lateral forces which were perpendicular to the body of the roller ski could be measured. Forces were resolved into the global coordinate system and compared with the force components measured by a force plate. A static and dynamic loading situation for the force measurement roller ski was performed to reveal the validity of the system. To demonstrate whether the force measurement roller ski would affect roller skiing performance on a treadmill, a maximum speed test with the V2 technique was performed by using both normal and force measurement roller skis. The force-time curves obtained by these two different force measurement systems were shown to have high similarity (coefficient of multiple correlations > 0.940). The absolute difference for the forces in the X and Z directions over one push-off cycle was 3.9–33.3 N. The extra weight (333 g) of the force measurement roller ski did not affect the performance of the skiers. Overall, the newly designed two-dimensional force measurement roller ski in this study is valid for use in future research during daily training for skate skiing techniques. Full article
(This article belongs to the Collection Sensors for Gait, Human Movement Analysis, and Health Monitoring)
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15 pages, 6045 KiB  
Article
Bandwidth Optimization of MEMS Accelerometers in Fluid Medium Environment
by Xiang Xu 1,2, Shuang Wu 1, Weidong Fang 2, Zhe Yu 2, Zeyu Jia 3, Xiaoxu Wang 3, Jian Bai 2,* and Qianbo Lu 1,*
1 Frontiers Science Center for Flexible Electronics (FSCFE), MIIT Key Laboratory of Flexible Electronics (KLoFE), Shaanxi Key Laboratory of Flexible Electronics (KLoFE), Institute of Flexible Electronics (IFE), Ningbo Institute of Northwestern Polytechnical University, Northwestern Polytechnical University, Xi’an 710072, China
2 State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310027, China
3 The Key Laboratory of Information Fusion Technology, Ministry of Education, School of Automation, Northwestern Polytechnical University, 127 West Youyi Road, Xi’an 710072, China
Sensors 2022, 22(24), 9855; https://doi.org/10.3390/s22249855 - 15 Dec 2022
Cited by 4 | Viewed by 2791
Abstract
There is a constraint between the dynamic range and the bandwidth of MEMS accelerometers. When the input acceleration is comparatively large, the squeeze film damping will increase dramatically with the increase in the oscillation amplitude, resulting in a decrease in bandwidth. Conventional models [...] Read more.
There is a constraint between the dynamic range and the bandwidth of MEMS accelerometers. When the input acceleration is comparatively large, the squeeze film damping will increase dramatically with the increase in the oscillation amplitude, resulting in a decrease in bandwidth. Conventional models still lack a complete vibration response analysis in large amplitude ratios and cannot offer a suitable guide in the optimization of such devices. In this paper, the vibration response analysis of the sensing unit of an accelerometer in large amplitude ratios is first completed. Then, the optimal design of the sensing unit is proposed to solve the contradiction between the dynamic range and the bandwidth of the accelerometer. Finally, the results of the vibration experiment prove that the maximum bandwidth can be achieved with 0~10g external acceleration, which shows the effectiveness of the design guide. The new vibration analysis with the complete model of squeeze film damping is applicable to all sensitive structures based on vibration, not limited to the MEMS accelerometer studied in this thesis. The bandwidth optimal scheme also provides a strong reference for similar structures with large oscillation amplitude ratios. Full article
(This article belongs to the Section Electronic Sensors)
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