Research

18 pages, 1286 KiB

Open AccessCommunication

Safe Displacements Device for All Conditions Blind People

by David Abreu, Arminda Suárez, Jonay Toledo and Benito Codina

Electronics 2023, 12(10), 2171; https://doi.org/10.3390/electronics12102171 - 10 May 2023

Viewed by 825

One of the challenges faced by the blind to achieve optimum mobility is obstacles detection and avoidance. The traditional aid is the mobility white cane, but nowadays, there are also electronic travel aids. However, none of them is widely used. The eBAT (electronic [...] Read more.

One of the challenges faced by the blind to achieve optimum mobility is obstacles detection and avoidance. The traditional aid is the mobility white cane, but nowadays, there are also electronic travel aids. However, none of them is widely used. The eBAT (electronic Buzzer for Autonomous Travel) has been designed to provide protection and easy usage, interacting with a user’s mobile phone. To improve its performance, a usage test was carried out by 25 totally blind users divided by sex, age range and autonomy in mobility. The main results are that the eBAT gives a reduction in the involuntary contacts but also decreases the walking speed. There are differences between sex, age and mobility groups but with limited statistical significance, and there are also some correlations between variables. Full article

(This article belongs to the Special Issue Design, Development and Testing of Wearable Devices)

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14 pages, 4668 KiB

Open AccessArticle

A Wireless Electrooculogram (EOG) Wearable Using Conductive Fiber Electrode

by Kee S. Moon, Sung Q. Lee, John S. Kang, Andrew Hnat and Deepa B. Karen

Electronics 2023, 12(3), 571; https://doi.org/10.3390/electronics12030571 - 23 Jan 2023

Cited by 1 | Viewed by 2738

Abstract

Electrooculography (EOG) is a technique for detecting electrical signals from the extra-ocular muscles. The EOG is a precise method for quantifying eye movements, including drowsiness-induced eye closure, and is also a promising technology for its potential use as a contributing mechanism for brain–computer [...] Read more.

Electrooculography (EOG) is a technique for detecting electrical signals from the extra-ocular muscles. The EOG is a precise method for quantifying eye movements, including drowsiness-induced eye closure, and is also a promising technology for its potential use as a contributing mechanism for brain–computer interface applications. Despite the fact that EOG signals change as humans move their eyes, it is still difficult to monitor eye movement patterns in natural behaviors, such as everyday activity. Wearable convenience is essential for obtaining EOG signals while moving freely. This paper proposes the development and use of semi-dry electrodes with low impedance and excellent wearability, as well as a small, portable device with wireless communication capabilities, to increase the likelihood of use in real-life scenarios. The semi-dry electrode produced by the electrospinning technique had an impedance that was 3.5 times lower than that of the existing dry electrode and demonstrated low impedance drift even after long-term use. Furthermore, three steps of eye motion separation were performed using a signal obtained from the wearable device. It was confirmed that the classification of eye movements was at a meaningful level. Full article

(This article belongs to the Special Issue Design, Development and Testing of Wearable Devices)

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35 pages, 16104 KiB

Open AccessArticle

A Novel Wearable Upper-Limb Rehabilitation Assistance Exoskeleton System Driven by Fluidic Muscle Actuators

by Shean-Juinn Chiou, Hsien-Ru Chu, I-Hsum Li and Lian-Wang Lee

Electronics 2023, 12(1), 196; https://doi.org/10.3390/electronics12010196 - 31 Dec 2022

Cited by 3 | Viewed by 1446

Abstract

This paper proposed a novel design using a torsion spring mechanism with a single fluidic muscle actuator (FMA) to drive a joint with one degree-of-freedom (DOF) through a steel wire and a proportional pressure regulating valve (PRV). We developed a 4-DOF wearable upper-limb [...] Read more.

This paper proposed a novel design using a torsion spring mechanism with a single fluidic muscle actuator (FMA) to drive a joint with one degree-of-freedom (DOF) through a steel wire and a proportional pressure regulating valve (PRV). We developed a 4-DOF wearable upper-limb rehabilitation assistance exoskeleton system (WURAES) that is suitable for assisting in the rehabilitation of patients with upper-limb injuries. This system is safe, has a simple mechanism, and exhibits upper-limb motion compliance. The developed WURAES enables patients with upper-limb musculoskeletal injuries and neurological disorders to engage in rehabilitation exercises. Controlling the joint is difficult because of the time-varying hysteresis properties of the FMA and the nonlinear motion between standard extension and flexion. To solve this problem, a proxy-based output feedback sliding mode control (POFSC) was developed to provide appropriate rehabilitation assistance power for the upper-limb exoskeleton and to maintain smooth and safe contact between the WURAES and the patient. The POFSC enables the overdamped dynamic of the WURAES to recover motion to be aligned with the target trajectory without a significant error overshoot caused by actuator saturation. The experimental results indicate that the proposed POFSC can control the designed WURAES effectively. The POFSC can monitor the exoskeleton system’s total disturbance and unknown state online and adapt to the exterior environment to enhance the control capability of the designed system. The results indicate that a single FMA with a torsion spring module exhibits a control response similar to a dual FMA configuration. Full article

(This article belongs to the Special Issue Design, Development and Testing of Wearable Devices)

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Graphical abstract

18 pages, 3827 KiB

Open AccessArticle

A Self-Tuned Method for Impedance-Matching of Planar-Loop Resonators in Conformable Wearables

by Sen Bing, Khengdauliu Chawang and J.-C. Chiao

Electronics 2022, 11(17), 2784; https://doi.org/10.3390/electronics11172784 - 04 Sep 2022

Cited by 5 | Viewed by 1387

Abstract

Loop structure has been used as a single resonator and in meta-materials. Variations from the loop structures such as split-ring resonators have been utilized as sensing elements in integrated devices for wearable applications or in array configurations for free-space resonance. Previously, impedance formula [...] Read more.

Loop structure has been used as a single resonator and in meta-materials. Variations from the loop structures such as split-ring resonators have been utilized as sensing elements in integrated devices for wearable applications or in array configurations for free-space resonance. Previously, impedance formula and equivalent circuit models have been developed for a single loop made of a conductor wire with a negligible wire diameter in the free space. Despite the features of being planar and small, however, the quality factors of single-loop resonators or antennas have not been sufficiently high to use them efficiently for sensing or power transfer. To investigate the limitation, we first experimentally examined the formula and equivalent circuits for a single loop made of planar metal sheets, along with finite element simulations. The loop performance factor was varied to validate the formula and equivalent circuits. Then a tuning element was utilized in the planar loop to improve resonance by providing distributed impedance-matching to the loop. The proposed tuning method was demonstrated with simulations and measurements. A new equivalent circuit model for the tuned loop resonator was established. Quality factors at resonance show significant improvement and the tuning can be done for a specific resonance order without changing the loop radius. It was also shown that the tuning method provided more robust performance for the resonator. The tuning mechanism is suitable for miniature planar device architectures in sensing applications, particularly for implants and wearables that have constraints in dimensions and form factors. The equivalent circuit model can also be applied for meta-materials in arrayed configurations. Full article

(This article belongs to the Special Issue Design, Development and Testing of Wearable Devices)

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18 pages, 15504 KiB

Open AccessArticle

Design and Implementation of an Intelligent Assistive Cane for Visually Impaired People Based on an Edge-Cloud Collaboration Scheme

by Yuqi Ma, Yanqing Shi, Moyu Zhang, Wei Li, Chen Ma and Yu Guo

Electronics 2022, 11(14), 2266; https://doi.org/10.3390/electronics11142266 - 20 Jul 2022

Cited by 3 | Viewed by 2812

Abstract

Visually impaired people face many inconveniences in daily life, and there are problems such as high prices and single functions in the market of assistance tools for visually impaired people. In this work, we designed and implemented a low-cost intelligent assistance cane, particularly [...] Read more.

Visually impaired people face many inconveniences in daily life, and there are problems such as high prices and single functions in the market of assistance tools for visually impaired people. In this work, we designed and implemented a low-cost intelligent assistance cane, particularly for visually impaired individuals, based on computer vision, sensors, and an edge-cloud collaboration scheme. Obstacle detection, fall detection, and traffic light detection functions have been designed and integrated for the convenience of moving for visually impaired people. We have also designed an image captioning function and object detection function with high-speed processing capability based on an edge-cloud collaboration scheme to improve the user experience. Experiments show that the performance metrics have an aerial obstacle detection accuracy of 92.5%, fall detection accuracy of 90%, and average image retrieval period of 1.124 s. It proves the characteristics of low power consumption, strong real-time performance, adaptability to multiple scenarios, and convenience, which can ensure the safety of visually impaired people when moving and can help them better perceive and understand the surrounding environment. Full article

(This article belongs to the Special Issue Design, Development and Testing of Wearable Devices)

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17 pages, 916 KiB

Open AccessArticle

Exploring Gaze Movement Gesture Recognition Method for Eye-Based Interaction Using Eyewear with Infrared Distance Sensor Array

by Kyosuke Futami, Yuki Tabuchi, Kazuya Murao and Tsutomu Terada

Electronics 2022, 11(10), 1637; https://doi.org/10.3390/electronics11101637 - 20 May 2022

Cited by 2 | Viewed by 1871

Abstract

With the spread of eyewear devices, people are increasingly using information devices in various everyday situations. In these situations, it is important for eyewear devices to have eye-based interaction functions for simple hands-free input at a low cost. This paper proposes a gaze [...] Read more.

With the spread of eyewear devices, people are increasingly using information devices in various everyday situations. In these situations, it is important for eyewear devices to have eye-based interaction functions for simple hands-free input at a low cost. This paper proposes a gaze movement recognition method for simple hands-free interaction that uses eyewear equipped with an infrared distance sensor. The proposed method measures eyelid skin movement using an infrared distance sensor inside the eyewear and applies machine learning to the time-series sensor data to recognize gaze movements (e.g., up, down, left, and right). We implemented a prototype system and conducted evaluations with gaze movements including factors such as movement directions at 45-degree intervals and the movement distance difference in the same direction. The results showed the feasibility of the proposed method. The proposed method recognized 5 to 20 types of gaze movements with an F-value of 0.96 to 1.0. In addition, the proposed method was available with a limited number of sensors, such as two or three, and robust against disturbance in some usage conditions (e.g., body vibration, facial expression change). This paper provides helpful findings for the design of gaze movement recognition methods for simple hands-free interaction using eyewear devices at a low cost. Full article

(This article belongs to the Special Issue Design, Development and Testing of Wearable Devices)

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17 pages, 831 KiB

Open AccessArticle

Augmenting Ear Accessories for Facial Gesture Input Using Infrared Distance Sensor Array

by Kyosuke Futami, Kohei Oyama and Kazuya Murao

Electronics 2022, 11(9), 1480; https://doi.org/10.3390/electronics11091480 - 05 May 2022

Cited by 6 | Viewed by 1550

Abstract

Simple hands-free input methods using ear accessories have been proposed to broaden the range of scenarios in which information devices can be operated without hands. Although many previous studies use canal-type earphones, few studies focused on the following two points: (1) A method [...] Read more.

Simple hands-free input methods using ear accessories have been proposed to broaden the range of scenarios in which information devices can be operated without hands. Although many previous studies use canal-type earphones, few studies focused on the following two points: (1) A method applicable to ear accessories other than canal-type earphones. (2) A method enabling various ear accessories with different styles to have the same hands-free input function. To realize these two points, this study proposes a method to recognize the user’s facial gesture using an infrared distance sensor attached to the ear accessory. The proposed method detects skin movement around the ear and face, which differs for each facial expression gesture. We created a prototype system for three ear accessories for the root of the ear, earlobe, and tragus. The evaluation results for nine gestures and 10 subjects showed that the F-value of each device was 0.95 or more, and the F-value of the pattern combining multiple devices was 0.99 or more, which showed the feasibility of the proposed method. Although many ear accessories could not interact with information devices, our findings enable various ear accessories with different styles to have eye-free and hands-free input ability based on facial gestures. Full article

(This article belongs to the Special Issue Design, Development and Testing of Wearable Devices)

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14 pages, 2412 KiB

Open AccessArticle

A Novel Fusion Pruning Algorithm Based on Information Entropy Stratification and IoT Application

by Ming Zhao, Min Hu, Meng Li, Sheng-Lung Peng and Junbo Tan

Electronics 2022, 11(8), 1212; https://doi.org/10.3390/electronics11081212 - 11 Apr 2022

Cited by 2 | Viewed by 1621

Abstract

To further reduce the size of the neural network model and enable the network to be deployed on mobile devices, a novel fusion pruning algorithm based on information entropy stratification is proposed in this paper. Firstly, the method finds similar filters and removes [...] Read more.

To further reduce the size of the neural network model and enable the network to be deployed on mobile devices, a novel fusion pruning algorithm based on information entropy stratification is proposed in this paper. Firstly, the method finds similar filters and removes redundant parts by Affinity Propagation Clustering, then secondly further prunes the channels by using information entropy stratification and batch normalization (BN) layer scaling factor, and finally restores the accuracy training by fine-tuning to achieve a reduced network model size without losing network accuracy. Experiments are conducted on the vgg16 and Resnet56 network using the cifar10 dataset. On vgg16, the results show that, compared with the original model, the parametric amount of the algorithm proposed in this paper is reduced by 90.69% and the computation is reduced to 24.46% of the original one. In ResNet56, we achieve a 63.82%-FLOPs reduction by removing 63.53% parameters. The memory occupation and computation speed of the new model are better than the baseline model while maintaining a high network accuracy. Compared with similar algorithms, the algorithm has obvious advantages in the dimensions of computational speed and model size. The pruned model is also deployed to the Internet of Things (IoT) as a target detection system. In addition, experiments show that the proposed model is able to detect targets accurately with low reasoning time and memory. It takes only 252.84 ms on embedded devices, thus matching the limited resources of IoT. Full article

(This article belongs to the Special Issue Design, Development and Testing of Wearable Devices)

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