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Search Results (1,315)

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16 pages, 3839 KiB  
Communication
Exploring the Effects of Gratitude Voice Waves on Cellular Behavior: A Pilot Study in Affective Mechanotransduction
by David del Rosario-Gilabert, Jesús Carbajo, Antonio Valenzuela-Miralles, Irene Vigué-Guix, Daniel Ruiz, Gema Esquiva and Violeta Gómez-Vicente
Appl. Sci. 2024, 14(20), 9400; https://doi.org/10.3390/app14209400 - 15 Oct 2024
Viewed by 280
Abstract
Emotional communication is a multi-modal phenomenon involving posture, gestures, facial expressions, and the human voice. Affective states systematically modulate the acoustic signals produced during speech production through the laryngeal muscles via the central nervous system, transforming the acoustic signal into a means of [...] Read more.
Emotional communication is a multi-modal phenomenon involving posture, gestures, facial expressions, and the human voice. Affective states systematically modulate the acoustic signals produced during speech production through the laryngeal muscles via the central nervous system, transforming the acoustic signal into a means of affective transmission. Additionally, a substantial body of research in sonobiology has shown that audible acoustic waves (AAW) can affect cellular dynamics. This pilot study explores whether the physical–acoustic changes induced by gratitude states in human speech could influence cell proliferation and Ki67 expression in non-auditory cells (661W cell line). We conduct a series of assays, including affective electroencephalogram (EEG) measurements, an affective text quantification algorithm, and a passive vibro-acoustic treatment (PVT), to control the CO2 incubator environment acoustically, and a proliferation assay with immunolabeling to quantify cell dynamics. Although a larger sample size is needed, the hypothesis that emotions can act as biophysical agents remains a plausible possibility, and feasible physical and biological pathways are discussed. In summary, studying the impact of gratitude AAW on cell biology represents an unexplored research area with the potential to enhance our understanding of the interaction between human cognition and biology through physics principles. Full article
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<p>Experimental set-up. (<b>a</b>) A passive acoustic treatment consisting of sound-absorbing and isolation panels was installed in a conventional incubator CO<sub>2</sub> (Forma™ Steri-Cycle™ CO<sub>2</sub> incubator, model 371, Thermo Electron Corporation, Waltham, MA, USA) to homogenize the acoustic field and reduce background noise. (<b>b</b>) The electro-acoustic radiation system consisted of a loudspeaker suspended on an acoustic support and connected to a digital audio player. The acoustic stimulus was radiated onto non-auditory cells at an L<sub>p</sub> of 80 dB for 72 h.</p>
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<p>Averaged log-transformed power spectrum [in 10*log<sub>10</sub>(µV<sup>2</sup>)/Hz] of the Fz electrode across the frequency range of 0.5–45 Hz. Upper: Log-transformed power spectrum in the resting-state (gray) and gratitude (mustard) conditions. Shaded areas denote, for each condition, the standard error of the mean (SEM). Lower: Difference in power spectrum between conditions. The dotted line denotes the zero-power difference. The solid dark line at the bottom of the x-axis denotes the significant cluster of <span class="html-italic">p</span>-values from a paired <span class="html-italic">t</span>-test (α-level = 0.05) for the resting-state and gratitude power spectrum (<span class="html-italic">p</span>-values were corrected for multiple comparisons via cluster-based permutation test; N = 100,000 randomizations).</p>
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<p>Averaged log-transformed power [in 10*log<sub>10</sub>(µV<sup>2</sup>)/Hz] across the Fz electrode for each frequency band for the resting-state (gray) and gratitude (mustard) conditions. Frequency bands are considered as theta (4–7.9 Hz), alpha (8–11.9 Hz), beta (12–29.9 Hz), and gamma (30–45 Hz). Solid lines within the violins indicate the mean value. Dashed lines denote the power at 0. Vertical lines denote the limit between frequency bands. Asterisks denote the significance of the difference between conditions established using paired <span class="html-italic">t</span>-tests: ** (<span class="html-italic">p</span> &lt; 0.01), and * (<span class="html-italic">p</span> ≤ 0.05).</p>
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<p>Emotional (ii) and synthesized emotional (iv) voice signal analysis. (<b>a</b>) Upper: Spectrogram of the emotional stimulus recorded by the participant after reading aloud the gratitude letter. Lower: Spectrogram of the synthesized emotional stimulus obtained from the text of the gratitude letter written by the participant using VoiceOver. (<b>b</b>) Upper: Spectrum of the emotional voice stimulus. Lower: Spectrum of the synthesized emotional voice stimulus. (<b>c</b>) Analysis of the magnitude-squared coherence (MSC) value [in AU] shows the similarities between the spectral content of (ii) the emotional signal and (iv) the synthesized emotional signal. The dashed red line denotes the 0.7 threshold for MSC values. The mean MSC value was 0.21 for a frequency bandwidth of 0–5000 Hz. AU, arbitrary units.</p>
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<p>In situ measurements of background noise from the CO<sub>2</sub> incubator. Gray line: Normalized mean L<sub>p</sub> of the CO<sub>2</sub> incubator without vibro-acoustic elements. Yellow line: Normalized mean L<sub>p</sub> of the CO<sub>2</sub> incubator with passive vibro-acoustic elements. PVT, passive vibro-acoustic treatment.</p>
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<p>The impact of emotional, non-emotional, and synthesized voice radiation on the 661W cell line: proliferation assay and Ki-67 protein expression. Confocal microscopy representative image depicts the Ki-67 control condition (<b>a</b>) and the Ki-67 emotional human voice condition (<b>b</b>). A passive vibro-acoustic treatment (PVT) was installed in the CO<sub>2</sub> incubator test. 661W cells seeded at a density of 20,000 cells/well and incubated for 72 h with the electro-acoustic system turned off (control group) and gratitude voice (emotional group). All acoustic stimuli were radiated using a loudspeaker-based system with an equivalent level of 80 dB. Cells were imaged with a laser-scanning confocal microscope at 40× magnification. Scale bar, 20 µm. (<b>c</b>) Absorbance values at 620 nm for crystal violet staining of 661W cells, seeded at a density of 2000 cells/well, and incubated for 72 h without acoustic stimuli (control group), with gratitude voice (emotional group), with <span class="html-italic">Don Quixote</span> text voice (non-emotional group), and with gratitude synthesized voice (synthesized group). Results are the mean ± standard deviation of three independent experiments (12 replicates per plate). ** <span class="html-italic">p</span>-value = 0.007. AU, arbitrary units. (<b>d</b>) Nuclear luminance values per pixel analyzed on a cell-by-cell basis for Ki-67 expression in the control and emotional conditions (n = 127 cell nuclei samples were analyzed in the control condition, and n = 172 in the emotional condition). Results are the mean ± standard deviation of three independent experiments. **** <span class="html-italic">p</span> = 0.000007. AU, arbitrary units.</p>
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14 pages, 5641 KiB  
Article
Estimation of Lower Limb Joint Angles Using sEMG Signals and RGB-D Camera
by Guoming Du, Zhen Ding, Hao Guo, Meichao Song and Feng Jiang
Bioengineering 2024, 11(10), 1026; https://doi.org/10.3390/bioengineering11101026 (registering DOI) - 15 Oct 2024
Viewed by 405
Abstract
Estimating human joint angles is a crucial task in motion analysis, gesture recognition, and motion intention prediction. This paper presents a novel model-based approach for generating reliable and accurate human joint angle estimation using a dual-branch network. The proposed network leverages combined features [...] Read more.
Estimating human joint angles is a crucial task in motion analysis, gesture recognition, and motion intention prediction. This paper presents a novel model-based approach for generating reliable and accurate human joint angle estimation using a dual-branch network. The proposed network leverages combined features derived from encoded sEMG signals and RGB-D image data. To ensure the accuracy and reliability of the estimation algorithm, the proposed network employs a convolutional autoencoder to generate a high-level compression of sEMG features aimed at motion prediction. Considering the variability in the distribution of sEMG signals, the proposed network introduces a vision-based joint regression network to maintain the stability of combined features. Taking into account latency, occlusion, and shading issues with vision data acquisition, the feature fusion network utilizes high-frequency sEMG features as weights for specific features extracted from image data. The proposed method achieves effective human body joint angle estimation for motion analysis and motion intention prediction by mitigating the effects of non-stationary sEMG signals. Full article
(This article belongs to the Special Issue Bioengineering of the Motor System)
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<p>Global framework.</p>
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<p>Windowing different scales.</p>
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<p>Multi-scale processing and updating.</p>
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<p>Feature fusion network.</p>
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<p>Dataset capture environment.</p>
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<p>Depth camera-processed data: the upper row shows the correct recognition scenarios in short (1.5 m) range and long range (3 m); the lower row shows the misrecognition scenarios.</p>
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<p>Knee angle, hip angle, and ankle angle prediction while walking on the treadmill based on different methods, the yellow shaded area represents the variance of the estimation results: (<b>a</b>) sEMG-based hip angle prediction; (<b>b</b>) vision-based hip angle prediction; (<b>c</b>) combined hip angle prediction; (<b>d</b>) sEMG-based knee angle prediction; (<b>e</b>) vision-based knee angle prediction; (<b>f</b>) combined knee angle prediction; (<b>g</b>) sEMG-based ankle angle prediction; (<b>h</b>) vision-based ankle angle prediction; (<b>i</b>) combined ankle angle prediction.</p>
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<p>Knee angle, hip angle, and ankle angle prediction while walking on the treadmill based on different methods, the yellow shaded area represents the variance of the estimation results: (<b>a</b>) sEMG-based hip angle prediction; (<b>b</b>) vision-based hip angle prediction; (<b>c</b>) combined hip angle prediction; (<b>d</b>) sEMG-based knee angle prediction; (<b>e</b>) vision-based knee angle prediction; (<b>f</b>) combined knee angle prediction; (<b>g</b>) sEMG-based ankle angle prediction; (<b>h</b>) vision-based ankle angle prediction; (<b>i</b>) combined ankle angle prediction.</p>
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<p>Knee angle predictions via different participants.</p>
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<p>Knee angle prediction with partial blocks.</p>
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17 pages, 8226 KiB  
Article
Design of a Capacitive Tactile Sensor Array System for Human–Computer Interaction
by Fei Fei, Zhenkun Jia, Changcheng Wu, Xiong Lu and Zhi Li
Sensors 2024, 24(20), 6629; https://doi.org/10.3390/s24206629 - 14 Oct 2024
Viewed by 280
Abstract
This paper introduces a novel capacitive sensor array designed for tactile perception applications. Utilizing an all-in-one inkjet deposition printing process, the sensor array exhibited exceptional flexibility and accuracy. With a resolution of up to 32.7 dpi, the sensor array was capable of capturing [...] Read more.
This paper introduces a novel capacitive sensor array designed for tactile perception applications. Utilizing an all-in-one inkjet deposition printing process, the sensor array exhibited exceptional flexibility and accuracy. With a resolution of up to 32.7 dpi, the sensor array was capable of capturing the fine details of touch inputs, making it suitable for applications requiring high spatial resolution. The design incorporates two multiplexers to achieve a scanning rate of 100 Hz, ensuring the rapid and responsive data acquisition that is essential for real-time feedback in interactive applications, such as gesture recognition and haptic interfaces. To evaluate the performance of the capacitive sensor array, an experiment that involved handwritten number recognition was conducted. The results demonstrated that the sensor accurately captured fingertip inputs with a high precision. When combined with an Auxiliary Classifier Generative Adversarial Network (ACGAN) algorithm, the sensor system achieved a recognition accuracy of 98% for various handwritten numbers from “0” to “9”. These results show the potential of the capacitive sensor array for advanced human–computer interaction applications. Full article
(This article belongs to the Section Sensors Development)
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<p>Sensor fabrication process: (<b>a</b>) a polyester film as a printing substrate; (<b>b</b>) PVA coating onto the polyester film; (<b>c</b>) printing process of the row electrode; (<b>d</b>) printing process of the column electrode; (<b>e</b>) printing process of the interconnects; (<b>f</b>) soldering of electronic components, and (<b>g</b>) the final fabricated sensor device.</p>
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<p>Design of the sensor system. (<b>a</b>) A 16 × 16 capacitive sensor with a pixel resolution of 32.7 dpi. (<b>b</b>) A 0.4 mm × 0.4 mm diamond sensing element and interconnects of 0.1 mm.</p>
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<p>Demonstration of the capacitive tactical sensor system. (<b>a</b>) The hardware system includes the capacitive sensor, the Arduino controller, the capacitance measurement module, and two multiplexers. (<b>b</b>) High-resolution micro-capacitive array. (<b>c</b>) Connection of the hardware system.</p>
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<p>Comparison of abnormal and normal capacitance values.</p>
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<p>(<b>a</b>) The dielectric between the emitter and the receiver is the photopolymer and air without the finger touching. (<b>b</b>) The dielectric between the emitter and the receiver is the photopolymer, air, and the finger. (<b>c</b>) Change in the sensor capacitance before and after finger touching.</p>
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<p>Sequence of capacitance values corresponding to the number “0” trajectory.</p>
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<p>Sliding motion with the index finger and the visualized trajectory of the number “0”.</p>
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<p>Visualized trajectories from numbers “1” to “9”.</p>
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<p>The training processes of the (<b>a</b>) GAN, (<b>b</b>) CGAN, and (<b>c</b>) ACGAN.</p>
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<p>The generator model of the ACGAN.</p>
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<p>The discriminator model of the ACGAN.</p>
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<p>The trajectory heatmaps of the numbers “0–9”: (<b>a</b>) trajectory heatmaps obtained by drawing numbers on the capacitive sensor using a finger; (<b>b</b>) trajectory heatmaps generated using a GAN model’s generator.</p>
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<p>The (<b>a</b>) loss and (<b>b</b>) auxiliary loss of the model, as well as the confusion matrix for the discriminator model on the (<b>c</b>) validation set and (<b>d</b>) fake image set.</p>
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19 pages, 1236 KiB  
Article
Multi-Task Diffusion Learning for Time Series Classification
by Shaoqiu Zheng, Zhen Liu, Long Tian, Ling Ye, Shixin Zheng, Peng Peng and Wei Chu
Electronics 2024, 13(20), 4015; https://doi.org/10.3390/electronics13204015 - 12 Oct 2024
Viewed by 301
Abstract
Current deep learning models for time series often face challenges with generalizability in scenarios characterized by limited samples or inadequately labeled data. By tapping into the robust generative capabilities of diffusion models, which have shown success in computer vision and natural language processing, [...] Read more.
Current deep learning models for time series often face challenges with generalizability in scenarios characterized by limited samples or inadequately labeled data. By tapping into the robust generative capabilities of diffusion models, which have shown success in computer vision and natural language processing, we see potential for improving the adaptability of deep learning models. However, the specific application of diffusion models in generating samples for time series classification tasks remains underexplored. To bridge this gap, we introduce the MDGPS model, which incorporates multi-task diffusion learning and gradient-free patch search (MDGPS). Our methodology aims to bolster the generalizability of time series classification models confronted with restricted labeled samples. The multi-task diffusion learning module integrates frequency-domain classification with random masked patches diffusion learning, leveraging frequency-domain feature representations and patch observation distributions to improve the discriminative properties of generated samples. Furthermore, a gradient-free patch search module, utilizing the particle swarm optimization algorithm, refines time series for specific samples through a pre-trained multi-task diffusion model. This process aims to reduce classification errors caused by random patch masking. The experimental results on four time series datasets show that the proposed MDGPS model consistently surpasses other methods, achieving the highest classification accuracy and F1-score across all datasets: 95.81%, 87.64%, 82.31%, and 100% in accuracy; and 95.21%, 82.32%, 78.57%, and 100% in F1-Score for Epilepsy, FD-B, Gesture, and EMG, respectively. In addition, evaluations in a reinforcement learning scenario confirm MDGPS’s superior performance. Ablation and visualization experiments further validate the effectiveness of its individual components. Full article
(This article belongs to the Special Issue Advances in Algorithm Optimization and Computational Intelligence)
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<p>The framework for the multi-task diffusion learning with gradient-free patch search for time series classification model.</p>
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<p>Flowchart depicting the operation of the gradient-free patch search module utilizing the particle swarm optimization algorithm.</p>
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<p>The training time (s) of different methods on the EMG dataset.</p>
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<p>The t-SNE visualization of the learned representations on the Epilepsy dataset.</p>
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<p>The t-SNE visualization of the learned representations on the FD-B dataset.</p>
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<p>The comparison results depict the ratio of defeated fighters between the red and blue sides in the intelligent agent and environment exchange reinforcement learning scenario.</p>
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<p>Comparative results on classification accuracy of reinforcement learning decisions based on the cart pole and the mountain car behavioural clones.</p>
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<p>Comparison results of reward values in behavioral cloning.</p>
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21 pages, 1550 KiB  
Article
Using 3D Hand Pose Data in Recognizing Human–Object Interaction and User Identification for Extended Reality Systems
by Danish Hamid, Muhammad Ehatisham Ul Haq, Amanullah Yasin, Fiza Murtaza and Muhammad Awais Azam
Information 2024, 15(10), 629; https://doi.org/10.3390/info15100629 (registering DOI) - 12 Oct 2024
Viewed by 424
Abstract
Object detection and action/gesture recognition have become imperative in security and surveillance fields, finding extensive applications in everyday life. Advancement in such technologies will help in furthering cybersecurity and extended reality systems through the accurate identification of users and their interactions, which plays [...] Read more.
Object detection and action/gesture recognition have become imperative in security and surveillance fields, finding extensive applications in everyday life. Advancement in such technologies will help in furthering cybersecurity and extended reality systems through the accurate identification of users and their interactions, which plays a pivotal role in the security management of an entity and providing an immersive experience. Essentially, it enables the identification of human–object interaction to track actions and behaviors along with user identification. Yet, it is performed by traditional camera-based methods with high difficulties and challenges since occlusion, different camera viewpoints, and background noise lead to significant appearance variation. Deep learning techniques also demand large and labeled datasets and a large amount of computational power. In this paper, a novel approach to the recognition of human–object interactions and the identification of interacting users is proposed, based on three-dimensional hand pose data from an egocentric camera view. A multistage approach that integrates object detection with interaction recognition and user identification using the data from hand joints and vertices is proposed. Our approach uses a statistical attribute-based model for feature extraction and representation. The proposed technique is tested on the HOI4D dataset using the XGBoost classifier, achieving an average F1-score of 81% for human–object interaction and an average F1-score of 80% for user identification, hence proving to be effective. This technique is mostly targeted for extended reality systems, as proper interaction recognition and users identification are the keys to keeping systems secure and personalized. Its relevance extends into cybersecurity, augmented reality, virtual reality, and human–robot interactions, offering a potent solution for security enhancement along with enhancing interactivity in such systems. Full article
(This article belongs to the Special Issue Extended Reality and Cybersecurity)
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<p>Multi-stage HOI recognition.</p>
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<p>Representation of set of 21 3D hand Landmarks and vertices.</p>
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<p>Confusion matrix for object recognition (hand joints).</p>
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<p>Confusion matrix for object recognition (aand vertices).</p>
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<p>Confusion matrix for object recognition (fusion concatenation).</p>
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<p>Object based F1-Score for interaction classification.</p>
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<p>User identification average F1-Score in object-wise interactions.</p>
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20 pages, 3585 KiB  
Article
A Study of Exergame System Using Hand Gestures for Wrist Flexibility Improvement for Tenosynovitis Prevention
by Yanqi Xiao, Nobuo Funabiki, Irin Tri Anggraini, Cheng-Liang Shih and Chih-Peng Fan
Information 2024, 15(10), 622; https://doi.org/10.3390/info15100622 - 10 Oct 2024
Viewed by 337
Abstract
Currently, as an increasing number of people have been addicted to using cellular phones, smartphone tenosynovitis has become common from long-term use of fingers for their operations. Hand exercise while playing video games, which is called exergame, can be a good solution [...] Read more.
Currently, as an increasing number of people have been addicted to using cellular phones, smartphone tenosynovitis has become common from long-term use of fingers for their operations. Hand exercise while playing video games, which is called exergame, can be a good solution to provide enjoyable daily exercise opportunities for its prevention, particularly, for young people. In this paper, we implemented a simple exergame system with a hand gesture recognition program made in Python using the Mediapipe library. We designed three sets of hand gestures to control the key operations to play the games as different exercises useful for tenosynovitis prevention. For evaluations, we prepared five video games running on a web browser and asked 10 students from Okayama and Hiroshima Universities, Japan, to play them and answer 10 questions in the questionnaire. Their playing results and System Usability Scale (SUS) scores confirmed the usability of the proposal, although we improved one gesture set to reduce its complexity. Moreover, by measuring the angles for maximum wrist movements, we found that the wrist flexibility was improved by playing the games, which verifies the effectiveness of the proposal. Full article
(This article belongs to the Special Issue Real-World Applications of Machine Learning Techniques)
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<p>Overview of the <span class="html-italic">exergame</span> system with hand gestures.</p>
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<p>Effective hand exercises for preventing <span class="html-italic">tenosynovitis</span>.</p>
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<p>Hand gestures in the <span class="html-italic">wrist exercise set</span>.</p>
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<p>Hand gestures in the <span class="html-italic">thumb exercise set</span>.</p>
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<p>Hand gestures in the <span class="html-italic">finger exercise set</span>.</p>
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<p>Twenty-one <span class="html-italic">key points</span> of one hand by <span class="html-italic">Mediapipe</span>.</p>
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<p>User view with frame rate.</p>
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<p>Flowchart for operation procedure of <span class="html-italic">exergame</span> system.</p>
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<p>Flowchart for hand gesture recognition using <span class="html-italic">Mediapipe</span>.</p>
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<p>Improved <span class="html-italic">space key</span> gesture for <span class="html-italic">wrist exercise set</span>.</p>
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<p>Four gestures for wrist bending angle measurement.</p>
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14 pages, 1402 KiB  
Article
Age Is a New Indicator of Long-Ball Kicking Performance in Young Soccer Players: Analysing Kinanthropometry, Flexibility and Strength
by Antonio Cejudo, José Manuel Armada-Zarco and Riccardo Izzo
Appl. Sci. 2024, 14(19), 9052; https://doi.org/10.3390/app14199052 - 7 Oct 2024
Viewed by 731
Abstract
(1) Background: The kick of the ball in soccer is considered one of the most important technical gestures in soccer. Despite this, there is little evidence on ball-striking performance factors in base soccer. The main objectives of the present study were to identify [...] Read more.
(1) Background: The kick of the ball in soccer is considered one of the most important technical gestures in soccer. Despite this, there is little evidence on ball-striking performance factors in base soccer. The main objectives of the present study were to identify the potential factors of long-ball kicking (LBK) performance and to determine the target training cut-off for LBK performance in young soccer players. (2) Methods: A cross-sectional observational study was conducted with 31 soccer players, with ages ranging from 12 to 18 years. Age, anthropometric data, sport experience, range of motion (ROM) and maximal isometric strength (MIS) of the lower limb were noted. Kick-of-the-ball performance was assessed by maximum ball displacement per kick. A k-mean cluster analysis determined two groups according to ball-kicking performance: low group (LPG-LBK) and high group (HPG-LBK). (3) Results: Differences were found between both groups in age, body mass, body mass index, leg length and knee flexion ROM (BF10 ≤ 6.33; δ ≥ 0.86 (moderate or higher)). Among the factors discussed above, age was the strongest predictor of ball-striking performance (odds ratio = 2.867; p = 0.003). The optimal cut-off for age predicting those players most likely to have a higher ball-striking performance was determined to be 13.5 years (p = 0.001; area under the curve = 85.3%). (4) Conclusions: Age over 13.5 increases the chances of a higher optimal ball-striking performance. The flexibility (knee flexion ROM) and strength (knee flexors) must be specifically trained in soccer players beginning at an early age. Full article
(This article belongs to the Special Issue Advances in Assessment of Physical Performance)
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<p>Assessment of hip and knee range of motion using the ROM-SPORT I battery.</p>
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<p>Assessment of the maximal isometric strength of the hip and knee flexors and extensors.</p>
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<p>Sensitivity, specificity, area under the curve and cut-off point of age as a predictor of long-ball kicking.</p>
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16 pages, 1994 KiB  
Article
Quantitatively Measuring Developmental Characteristics in the Use of Deictic Verbs for Japanese-Speaking Children: A Pilot Study
by Hiroshi Asaoka and Tomoya Takahashi
Languages 2024, 9(10), 321; https://doi.org/10.3390/languages9100321 - 7 Oct 2024
Viewed by 442
Abstract
The acquisition of deictic verbs is a significant milestone in language development. This complex process requires an understanding of the interplay between the personal pronouns “I/you” and deictic verbs. Although demonstrating the cognitive processes associated with deictic shifting through data is valuable, research [...] Read more.
The acquisition of deictic verbs is a significant milestone in language development. This complex process requires an understanding of the interplay between the personal pronouns “I/you” and deictic verbs. Although demonstrating the cognitive processes associated with deictic shifting through data is valuable, research issues regarding data accuracy and the spatial arrangement of the self and other remain unresolved. This pilot study aimed to quantitatively measure the body movements of Japanese-speaking children during their utterances of “come/go”. Twelve typically developing children aged 6–7 participated in this study. Multiple scenarios were set up where the researcher presented phrases using “come/go” with deictic gestures, such as moving one’s upper body forward or backward, and the participant replied with “come/go”. When performing a role, the researcher sat face-to-face or side-by-side with the participant, depending on the type of question–response. It is possible that there is a learning process whereby verbal responses using “come/go” align with corresponding body movements in the specific question type. This process is deeply involved in the development of perspective-taking abilities. Future research with relatively large samples and cross-cultural comparisons is warranted to deepen the understanding of this linguistic acquisition process and its implications. Full article
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<p>Solutions to research issues. Note. Body movements were depicted as upper-body movements according to the procedures of this study and were exaggerated to ensure clarity, although in reality, they were slight movements.</p>
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<p>Aerial view of the set-up.</p>
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<p>Flowchart of the procedure. Note. Double rectangles indicate actions by both the researcher and participant; rectangles indicate actions by the researcher, and diamonds indicate actions by the participant. The numbers in parentheses correspond to those in the main text.</p>
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<p>Verbal expressions and body movements in each position. Note. Bold and fine letters indicate the correspondence between the verbs and movements. The participant’s lines indicate correct responses, whereas the participant’s arrows indicate upper-body movements based on actual directions.</p>
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20 pages, 3829 KiB  
Article
Beyond Granularity: Enhancing Continuous Sign Language Recognition with Granularity-Aware Feature Fusion and Attention Optimization
by Yao Du, Taiying Peng and Xiaohui Hu
Appl. Sci. 2024, 14(19), 8937; https://doi.org/10.3390/app14198937 - 4 Oct 2024
Viewed by 518
Abstract
The advancement of deep learning techniques has significantly propelled the development of the continuous sign language recognition (cSLR) task. However, the spatial feature extraction of sign language videos in the RGB space tends to focus on the overall image information while neglecting the [...] Read more.
The advancement of deep learning techniques has significantly propelled the development of the continuous sign language recognition (cSLR) task. However, the spatial feature extraction of sign language videos in the RGB space tends to focus on the overall image information while neglecting the perception of traits at different granularities, such as eye gaze and lip shape, which are more detailed, or posture and gestures, which are more macroscopic. Exploring the efficient fusion of visual information of different granularities is crucial for accurate sign language recognition. In addition, applying a vanilla Transformer to sequence modeling in cSLR exhibits weak performance because specific video frames could interfere with the attention mechanism. These limitations constrain the capability to understand potential semantic characteristics. We introduce a feature fusion method for integrating visual features of disparate granularities and refine the metric of attention to enhance the Transformer’s comprehension of video content. Specifically, we extract CNN feature maps with varying receptive fields and employ a self-attention mechanism to fuse feature maps of different granularities, thereby obtaining multi-scale spatial features of the sign language framework. As for video modeling, we first analyze why the vanilla Transformer failed in cSLR and observe that the magnitude of the feature vectors of video frames could interfere with the distribution of attention weights. Therefore, we utilize the Euclidean distance among vectors to measure the attention weights instead of scaled-dot to enhance dynamic temporal modeling capabilities. Finally, we integrate the two components to construct the model MSF-ET (Multi-Scaled feature Fusion–Euclidean Transformer) for cSLR and train the model end-to-end. We perform experiments on large-scale cSLR benchmarks—PHOENIX-2014 and Chinese Sign Language (CSL)—to validate the effectiveness. Full article
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<p>Currently, most video spatial representation methods for cSLR extract features by pre-trained CNN backbone networks ((<b>left</b>) in the figure). Although the approach can extract high-level semantic information, it lacks perception of details, such as mouth shape and gaze, which are important for understanding sign language. We propose a multi-scale feature fusion method based on self-attention mechanism ((<b>right</b>) in figure), which enables more comprehensive extraction of semantic information.</p>
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<p>Overall model architecture. Our proposed MSF-ET model consists of three main components: spatial encoder, feature fusion module, and temporal encoder. The spatial encoder is composed of multiple 2D convolutional layers, followed by max-pooling to downsample the feature maps with different receptive fields. The feature fusion module uses a self-attention mechanism to fuse the multi-scaled features of the frames. The temporal encoder is composed of the encoder based on Euclidean distance self-attention model and local Transformer layer. The encoder learns the contextual information of the video and the local features for glosses alignment. Finally, connectionist temporal classification (CTC) is used to train the model and decode the gloss sequences.</p>
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<p>Multi-scaled features integration and fusion. The spatial encoder outputs feature maps of sizes 3 and 7, respectively. These feature maps are first flattened into 1D vectors. Then, a special token <math display="inline"><semantics> <mrow> <mo>[</mo> <mi>c</mi> <mi>l</mi> <mi>s</mi> <mo>]</mo> </mrow> </semantics></math> is added to the head of the vector, similar to ViT. Next, the flattened vectors are added with trainable position embedding and then utilize the Transformer encoder to obtain the global context information of both feature maps. Finally, the two <math display="inline"><semantics> <mrow> <mo>[</mo> <mi>c</mi> <mi>l</mi> <mi>s</mi> <mo>]</mo> </mrow> </semantics></math> are concatenated to achieve multi-scale feature fusion.</p>
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<p>The demo for the attention map of vanilla Transformer. The heatmap denotes the attention scores, and the bar above the heatmap is the magnitude of key vectors. The figure indicates that the distribution of attention weights is overly concentrated in regions where the key vectors have longer magnitudes, thereby drowning out information from other positions and hindering the Transformer’s ability to fully comprehend the global information within the sequence.</p>
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<p>The detail about self-attention with Euclidean distance and local window. We assume that the window size is 5. Therefore, every frame interacts with others by attention mechanism in the window centered on itself.</p>
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<p>The CAM visualization of attention weights corresponding to feature maps at different scales. We applied this visualization to videos of different sign language performers to demonstrate the generalizability of the results. ((<b>A</b>) is sourced from ‘01April_2010_Thursday_heute_default-1’ in the PHOENIX2014 validation set. (<b>B</b>) is sourced from ‘03November_2010_Wednesday_tagesschau_default-7’ in the PHOENIX-2014 validation set.)</p>
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<p>An example of attention weight visualization for a Transformer utilizing Euclidean distance-based metrics. The sample data used in this figure are consistent with those in <a href="#applsci-14-08937-f004" class="html-fig">Figure 4</a>. It is evident that the use of Euclidean distance significantly alleviates the phenomenon of attention sparsity.</p>
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<p>Relationship between inference time and video sequence length during model inference.</p>
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10 pages, 215 KiB  
Article
Death Images in Michael Haneke’s Films
by Susana Viegas
Philosophies 2024, 9(5), 155; https://doi.org/10.3390/philosophies9050155 - 1 Oct 2024
Viewed by 657
Abstract
Although meditating on death has long been a central philosophical practice and is gaining prominence in modern European public discourse, certain misconceptions still persist. The Austrian filmmaker Michael Haneke does not shy away from confronting real and performed images of death, combining a [...] Read more.
Although meditating on death has long been a central philosophical practice and is gaining prominence in modern European public discourse, certain misconceptions still persist. The Austrian filmmaker Michael Haneke does not shy away from confronting real and performed images of death, combining a denouncing cinematic approach with no less polemic aesthetic and ethical theories. Certainly, visually shocking and disturbing films can, in their own way, challenge the boundaries of what is thinkable, at times even touching upon the unthinkable. Images of death and death-related themes are particularly pervasive in Haneke’s films. His films raise significant philosophical and ethical questions about mortality, violence, death, and ageing. This analysis is a tentative attempt to map how Haneke explores representations of death and dying in Benny’s Video (1992) and Funny Games (1997), with particular reference to the rewind gesture depicted in both films. In doing so, it aims to examine the conversation such films prompt between moving images and the audience. Full article
7 pages, 230 KiB  
Perspective
Investigation Methods for Vocal Onset—A Historical Perspective
by Bernhard Richter, Matthias Echternach and Louisa Traser
Bioengineering 2024, 11(10), 989; https://doi.org/10.3390/bioengineering11100989 - 30 Sep 2024
Viewed by 502
Abstract
The topic of phonation onset gestures is of great interest to singers, acousticians, and voice physiologists alike. The vocal pedagogue and voice researcher Manuel Garcia, in the mid-19th century, first coined the term “coup de la glotte”. Given that Garcia defined the process [...] Read more.
The topic of phonation onset gestures is of great interest to singers, acousticians, and voice physiologists alike. The vocal pedagogue and voice researcher Manuel Garcia, in the mid-19th century, first coined the term “coup de la glotte”. Given that Garcia defined the process as “a precise articulation of the glottis that leads to a precise and clean tone attack”, the term can certainly be linked to the concept of “vocal onset” as we understand it today. However, Garcia did not, by any means, have the technical measures at his disposal to investigate this phenomenon. In order to better understand modern ways of investigating vocal onset—and the limitations that still exist—it seems worthwhile to approach the subject from a historical perspective. High-speed video laryngoscopy (HSV) can be regarded as the gold standard among today’s examination methods. Nonetheless, it still does not allow the three-dimensionality of vocal fold vibrations to be examined as it relates to vocal onset. Clearly, measuring methods in voice physiology have developed fundamentally since Garcia’s time. This offers grounds for hope that the still unanswered questions around the phenomenon of vocal onset will be resolved in the near future. One promising approach could be to develop ultra-fast three-dimensional MRI further. Full article
(This article belongs to the Special Issue The Biophysics of Vocal Onset)
16 pages, 4954 KiB  
Article
Real-Time Hand Gesture Monitoring Model Based on MediaPipe’s Registerable System
by Yuting Meng, Haibo Jiang, Nengquan Duan and Haijun Wen
Sensors 2024, 24(19), 6262; https://doi.org/10.3390/s24196262 - 27 Sep 2024
Viewed by 567
Abstract
Hand gesture recognition plays a significant role in human-to-human and human-to-machine interactions. Currently, most hand gesture detection methods rely on fixed hand gesture recognition. However, with the diversity and variability of hand gestures in daily life, this paper proposes a registerable hand gesture [...] Read more.
Hand gesture recognition plays a significant role in human-to-human and human-to-machine interactions. Currently, most hand gesture detection methods rely on fixed hand gesture recognition. However, with the diversity and variability of hand gestures in daily life, this paper proposes a registerable hand gesture recognition approach based on Triple Loss. By learning the differences between different hand gestures, it can cluster them and identify newly added gestures. This paper constructs a registerable gesture dataset (RGDS) for training registerable hand gesture recognition models. Additionally, it proposes a normalization method for transforming hand gesture data and a FingerComb block for combining and extracting hand gesture data to enhance features and accelerate model convergence. It also improves ResNet and introduces FingerNet for registerable single-hand gesture recognition. The proposed model performs well on the RGDS dataset. The system is registerable, allowing users to flexibly register their own hand gestures for personalized gesture recognition. Full article
(This article belongs to the Section Sensing and Imaging)
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<p>Gesture classification implementation process.</p>
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<p>Gesture data. (1) and (2) represent gesture photographs for two different gestures.</p>
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<p>MediaPipe finger landmark. The red dots are the 21 key points selected for the hand, which are connected by a green line to form a complete line of identification of the hand.</p>
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<p>FingerComb block.</p>
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<p>Structure of FingerNet.</p>
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<p>Training process.</p>
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<p>Test results box diagram. The parts marked in red are the gestures in this class that have the smallest L2 distance compared to the other gestures.</p>
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<p>Real-time gesture detection.</p>
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12 pages, 474 KiB  
Article
Communication Skills in Toddlers Exposed to Maternal SARS-CoV-2 during Pregnancy
by Enrico Apa, Nicole Carrie Tegmeyer, Concetta D’Adamo, Eleonora Lovati, Chiara Cocchi, Paola Allegra, Francesco Ostello, Daniele Monzani, Elisabetta Genovese and Silvia Palma
Life 2024, 14(10), 1237; https://doi.org/10.3390/life14101237 - 27 Sep 2024
Viewed by 401
Abstract
Studies about the effects of SARS-CoV-2 on pregnant women and children born to positive women are controversial with regard to possible inner ear-related damage but most of them do not detect the involvement of this virus in auditory function. However, only a few [...] Read more.
Studies about the effects of SARS-CoV-2 on pregnant women and children born to positive women are controversial with regard to possible inner ear-related damage but most of them do not detect the involvement of this virus in auditory function. However, only a few studies on long-term effects on language development are currently available because of the recent onset of the pandemic. The aim of this study was to investigate the impact of SARS-CoV-2 infection on perceptual and expressive abilities and the emerging development of communication in young children. To this purpose, the MacArthur–Bates Communicative Development Inventory—Words and Gestures form (CDI-WG), was administered to parents. In total, 115 children whose mother was infected by SARS-CoV-2 during pregnancy were enrolled in the study and evaluated at the Audiology Service of the Modena University Hospital. All children underwent Otoacoustic Emissions (OAE) at birth: 114/115 had a “pass” result bilaterally, while 1 case had a unilateral “refer” result. Overall, 110/115 newborns (95.65%) underwent audiological evaluation between 10–18 months of age. In 5/110 patients (3.6%), the Pure Tone Average (PTA) result was equal to 35 dB; one case had a hearing threshold of around 50 dB due to a bilateral effusive otitis media. A notable finding was the percentage of children with tubal dysfunction in both evaluations, within 2 months of age and around 12 months of age. Most children revealed normal hearing. The CDI-WG was completed by 56/115 families. The rate of children below the fifth percentile was 8.9% for sentences understood, 12.5% for words understood, and 5.4% for words produced. Concerning CDI-Gestures, only 2 children (3.6%) were below the fifth percentile. A structured audiological follow-up in association with the evaluation of communication skills of children appears fundamental, particularly in the years of maximum neuroplasticity. Long-term studies are still necessary to evaluate the possible consequences of the pandemic. Full article
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<p>Language quotients of CDI-WG according to the trimester of maternal SARS-CoV-2 infection. Each box is included between the first and third quartile; the box’s height is equivalent to the inter-quartile range (IQR) and contains 50% of the measurements. Values that deviate from the box by more than 1.5 of IQR upward or downward are considered potential outliers and are represented with × or °.</p>
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27 pages, 2184 KiB  
Review
The “What” and “How” of Pantomime Actions
by Raymond R. MacNeil and James T. Enns
Vision 2024, 8(4), 58; https://doi.org/10.3390/vision8040058 - 26 Sep 2024
Viewed by 402
Abstract
Pantomimes are human actions that simulate ideas, objects, and events, commonly used in conversation, performance art, and gesture-based interfaces for computing and controlling robots. Yet, their underlying neurocognitive mechanisms are not well understood. In this review, we examine pantomimes through two parallel lines [...] Read more.
Pantomimes are human actions that simulate ideas, objects, and events, commonly used in conversation, performance art, and gesture-based interfaces for computing and controlling robots. Yet, their underlying neurocognitive mechanisms are not well understood. In this review, we examine pantomimes through two parallel lines of research: (1) the two visual systems (TVS) framework for visually guided action, and (2) the neuropsychological literature on limb apraxia. Historically, the TVS framework has considered pantomime actions as expressions of conscious perceptual processing in the ventral stream, but an emerging view is that they are jointly influenced by ventral and dorsal stream processing. Within the apraxia literature, pantomimes were historically viewed as learned motor schemas, but there is growing recognition that they include creative and improvised actions. Both literatures now recognize that pantomimes are often created spontaneously, sometimes drawing on memory and always requiring online cognitive control. By highlighting this convergence of ideas, we aim to encourage greater collaboration across these two research areas, in an effort to better understand these uniquely human behaviors. Full article
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<p>Idealized representation of the kinematic differences in the aperture scaling profiles of real and pantomime grasps. (<b>A</b>) The top image (red border) depicts a power grasp on a standard-sized beaker, while the bottom image (blue border) depicts a precision grasp on a graduated cylinder beaker. (<b>B</b>) This graph represents how aperture size varies over time for real grasps. A pre-contact “grip overshoot” is reliably observed in the case of both power (red line) and precision (blue line) grasps. This functions to create a margin of safety for avoiding target collision and establishing a secure grip upon contact. Peak grip aperture is reached during this overshoot phase of grip aperture scaling. (<b>C</b>) The aperture scaling profile for pantomime grasps. The lines of the precision (blue) and power (red) grasps are overlaid with those of real grasps (transparent). In this example, we see that the grip overshoot is conspicuously absent for pantomimed grasps and that peak grip aperture is attained later in the reach trajectory.</p>
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<p>Simplified schematic of the dual-route model of pantomime production proposed by Rothi et al. [<a href="#B146-vision-08-00058" class="html-bibr">146</a>,<a href="#B147-vision-08-00058" class="html-bibr">147</a>]. Different modalities can elicit the pantomime’s performance. The experimenter may make a verbal request—e.g., “show me how you hammer a nail”—or perform the pantomime themselves for imitation by the patient. Alternatively, the patient may have to pantomime an object’s use after it is presented in physical or pictorial form. In the case of the former, processing will usually proceed through the lexical route, allowing the retrieval of the appropriate motor schema. This may need to be mapped to knowledge about what the object is used for (i.e., action semantics). If the input is gestural, a direct route allows for “on the fly” imitation, without any semantic processing. The object recognition system allows structural knowledge to activate the appropriate motor schema in the absence of a patient being able to explicitly report on the object’s conventional function.</p>
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<p>The Two Action Systems Plus (2AS+) model of real and pantomimed actions, based on [<a href="#B35-vision-08-00058" class="html-bibr">35</a>,<a href="#B114-vision-08-00058" class="html-bibr">114</a>,<a href="#B150-vision-08-00058" class="html-bibr">150</a>]. The dorso-dorsal channel supports grasp-to-move actions and novel tool use by providing online visual feedback of object affordances. It originates in the primary visual cortex (V1) and projects to the superior parietal lobe, where it continues to the dorsal premotor area. The ventro-dorsal channel (purple) supports real and pantomimed familiar tool use. With input originating in V1, it projects to areas in the inferior parietal lobe, including the supramarginal gyrus (SMG), and terminates in the ventral premotor area. The SMG serves as a critical hub for integrating ventral stream (red arrow) object representations and sematic knowledge with the sensorimotor processing of the ventro-dorsal and dorso-dorsal channels. The “plus” in the model refers to a circuit of reciprocal connections formed between the inferior frontal gyrus and SMG. This circuit is proposed to serve as an action selection module, resolving competing options for motor output corresponding to object transport (move, dorso-dorsal) versus function (use, ventro-dorsal).</p>
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<p>Schematic of the working memory model of pantomime production proposed by Bartolo et al. [<a href="#B138-vision-08-00058" class="html-bibr">138</a>]. This model builds on the work of Rothi et al. [<a href="#B146-vision-08-00058" class="html-bibr">146</a>]. The authors view pantomimes as creative gestures that are formed de novo. Working memory, conceptualized as a workspace, is proposed to operate as an obligatory creative mechanism that combines sensory input (i.e., the visual or auditory action prompt), conceptual knowledge (action semantics), and procedural memory (action lexicon) to support pantomime production. The visuomotor conversion module facilitates “on-the-fly” imitation, which may or may not require working memory (reflected by dashed arrows). The model’s formulation was motivated by observations of a patient known by the initials VL. Tests of VL’s gestural ability revealed a near-selective deficit in pantomime production, while cognitive testing revealed a selective impairment in working memory. See text for additional details.</p>
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<p>The technical reasoning (neurocognitive) model of pantomime. See text for additional details. Reproduced from Osiurak et al. [<a href="#B169-vision-08-00058" class="html-bibr">169</a>] (Creative Commons).</p>
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13 pages, 24253 KiB  
Article
A Multimodal Bracelet to Acquire Muscular Activity and Gyroscopic Data to Study Sensor Fusion for Intent Detection
by Daniel Andreas, Zhongshi Hou, Mohamad Obada Tabak, Anany Dwivedi and Philipp Beckerle
Sensors 2024, 24(19), 6214; https://doi.org/10.3390/s24196214 - 25 Sep 2024
Viewed by 765
Abstract
Researchers have attempted to control robotic hands and prostheses through biosignals but could not match the human hand. Surface electromyography records electrical muscle activity using non-invasive electrodes and has been the primary method in most studies. While surface electromyography-based hand motion decoding shows [...] Read more.
Researchers have attempted to control robotic hands and prostheses through biosignals but could not match the human hand. Surface electromyography records electrical muscle activity using non-invasive electrodes and has been the primary method in most studies. While surface electromyography-based hand motion decoding shows promise, it has not yet met the requirements for reliable use. Combining different sensing modalities has been shown to improve hand gesture classification accuracy. This work introduces a multimodal bracelet that integrates a 24-channel force myography system with six commercial surface electromyography sensors, each containing a six-axis inertial measurement unit. The device’s functionality was tested by acquiring muscular activity with the proposed device from five participants performing five different gestures in a random order. A random forest model was then used to classify the performed gestures from the acquired signal. The results confirmed the device’s functionality, making it suitable to study sensor fusion for intent detection in future studies. The results showed that combining all modalities yielded the highest classification accuracies across all participants, reaching 92.3±2.6% on average, effectively reducing misclassifications by 37% and 22% compared to using surface electromyography and force myography individually as input signals, respectively. This demonstrates the potential benefits of sensor fusion for more robust and accurate hand gesture classification and paves the way for advanced control of robotic and prosthetic hands. Full article
(This article belongs to the Section Wearables)
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<p>Pictures of the bracelet showing the overall design with the main module marked by the red dashed circle (<b>left</b>) and a detailed view of the sub-modules that are connected by white flexible links (<b>right</b>). The sEMG sensors protrude the cases by 3 mm to ensure good contact of the electrodes with the user’s skin.</p>
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<p>Schematic of a sub-module, housing a Trigno Avanti sEMG sensor from Delsys, Natick, USA, with an integrated 6-axis IMU, which can move vertically to transmit force to the four FSRs above.</p>
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<p>Pictures showing the structure of the main module of the bracelet. The lower half is identical to the sub-modules and contains an sEMG sensor and the PCB with FSRs in each corner, as shown in the upper pictures. The upper half of the main module provides space for a lithium polymer battery and the main PCB, as shown in the lower pictures.</p>
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<p>PCB layout with an ESP32 microcontroller and an analog multiplexer to allow data acquisition of 24 FSRs and wireless operation.</p>
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<p>Experimental setup for data acquisition to test the functionality of the bracelet. The participants performed the gestures in a random order while wearing the bracelet on the forearm.</p>
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<p>Gestures that were performed in a randomized order by the participants during data acquisition for 20 rounds.</p>
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<p>Confusion matrices from K-fold cross-validation averaged across all five participants for sEMG, FMG, and IMU as input signals decoded by a random forest classifier. Overall accuracies: sEMG: <math display="inline"><semantics> <mrow> <mn>87.8</mn> <mo>±</mo> <mn>6.3</mn> <mo>%</mo> </mrow> </semantics></math>, FMG: <math display="inline"><semantics> <mrow> <mn>90.1</mn> <mo>±</mo> <mn>4.5</mn> <mo>%</mo> </mrow> </semantics></math>, IMU: <math display="inline"><semantics> <mrow> <mn>64.0</mn> <mo>±</mo> <mn>5.3</mn> <mo>%</mo> </mrow> </semantics></math>. FMG yields better results than EMG and IMU as input signals for classifying five different hand gestures.</p>
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<p>Confusion matrices averaged across all five participants for different combinations of input signals decoded by a random forest classifier. Overall accuracies: sEMG + IMU: <math display="inline"><semantics> <mrow> <mn>85.0</mn> <mo>±</mo> <mn>5.1</mn> <mo>%</mo> </mrow> </semantics></math>, FMG + IMU: <math display="inline"><semantics> <mrow> <mn>89.5</mn> <mo>±</mo> <mn>3.3</mn> <mo>%</mo> </mrow> </semantics></math>, sEMG + FMG: <math display="inline"><semantics> <mrow> <mn>91.9</mn> <mo>±</mo> <mn>3.0</mn> <mo>%</mo> </mrow> </semantics></math>, sEMG + FMG + IMU: <math display="inline"><semantics> <mrow> <mn>92.3</mn> <mo>±</mo> <mn>2.6</mn> <mo>%</mo> </mrow> </semantics></math>. The combinations of sEMG + IMU and FMG + IMU resulted in lower overall classification accuracies than using sEMG and FMG individually as input signals. The combination of all three input signals yielded the best results.</p>
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<p>Time series plot of sEMG, IMU, and FSR signals acquired from participant 1 in the second trial. The gestures were indicated by the computer prompt in a random order. The transition times between gestures are shaded gray and were disregarded from training and testing the RF model. For better readability, IMU data were only plotted from one of the six modules, while FSR data were plotted for the second sensor of each module only.</p>
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