scholarly journals A Study on the Classification Effect of sEMG Signals in Different Vibration Environments Based on the LDA Algorithm

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6234
Author(s):  
Yanchao Wang ◽  
Ye Tian ◽  
Jinying Zhu ◽  
Haotian She ◽  
Hiroshi Yokoi ◽  
...  
Keyword(s):  
Working Conditions ◽  
Working Environment ◽  
Vibration Frequencies ◽  
Disabled People ◽  
Semg Signal ◽  
Zero Crossing ◽  
Myoelectric Prosthesis ◽  
Linear Discriminant ◽  
Average Accuracy ◽  
Semg Signals

Myoelectric prosthesis has become an important aid to disabled people. Although it can help people to recover to a nearly normal life, whether they can adapt to severe working conditions is a subject that is yet to be studied. Generally speaking, the working environment is dominated by vibration. This paper takes the gripping action as its research object, and focuses on the identification of grasping intentions under different vibration frequencies in different working conditions. In this way, the possibility of the disabled people who wear myoelectric prosthesis to work in various vibration environment is studied. In this paper, an experimental test platform capable of simulating 0–50 Hz vibration was established, and the Surface Electromyography (sEMG) signals of the human arm in the open and grasping states were obtained through the MP160 physiological record analysis system. Considering the reliability of human intention recognition and the rapidity of algorithm processing, six different time-domain features and the Linear Discriminant Analysis (LDA) classifier were selected as the sEMG signal feature extraction and recognition algorithms in this paper. When two kinds of features, Zero Crossing (ZC) and Root Mean Square (RMS), were used as input, the accuracy of LDA algorithm can reach 96.9%. When three features, RMS, Minimum Value (MIN), and Variance (VAR), were used as inputs, the accuracy of the LDA algorithm can reach 98.0%. When the six features were used as inputs, the accuracy of the LDA algorithm reached 98.4%. In the analysis of different vibration frequencies, it was found that when the vibration frequency reached 20 Hz, the average accuracy of the LDA algorithm in recognizing actions was low, while at 0 Hz, 40 Hz and 50 Hz, the average accuracy was relatively high. This is of great significance in guiding disabled people to work in a vibration environment in the future.

scholarly journals Elements Influencing sEMG-Based Gesture Decoding: Muscle Fatigue, Forearm Angle and Acquisition Time

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7713
Author(s):  
Zengyu Qing ◽  
Zongxing Lu ◽  
Yingjie Cai ◽  
Jing Wang
Keyword(s):  
Muscle Fatigue ◽  
Probabilistic Neural Network ◽  
Classification Model ◽  
Acquisition Time ◽  
Classification Models ◽  
Research Attention ◽  
Zero Crossing ◽  
Linear Discriminant ◽  
Decoding Accuracy ◽  
Semg Signals

The surface Electromyography (sEMG) signal contains information about movement intention generated by the human brain, and it is the most intuitive and common solution to control robots, orthotics, prosthetics and rehabilitation equipment. In recent years, gesture decoding based on sEMG signals has received a lot of research attention. In this paper, the effects of muscle fatigue, forearm angle and acquisition time on the accuracy of gesture decoding were researched. Taking 11 static gestures as samples, four specific muscles (i.e., superficial flexor digitorum (SFD), flexor carpi ulnaris (FCU), extensor carpi radialis longus (ECRL) and finger extensor (FE)) were selected to sample sEMG signals. Root Mean Square (RMS), Waveform Length (WL), Zero Crossing (ZC) and Slope Sign Change (SSC) were chosen as signal eigenvalues; Linear Discriminant Analysis (LDA) and Probabilistic Neural Network (PNN) were used to construct classification models, and finally, the decoding accuracies of the classification models were obtained under different influencing elements. The experimental results showed that the decoding accuracy of the classification model decreased by an average of 7%, 10%, and 13% considering muscle fatigue, forearm angle and acquisition time, respectively. Furthermore, the acquisition time had the biggest impact on decoding accuracy, with a maximum reduction of nearly 20%.

Semg Based Recognition Of Hand Motions For Lower Limb Prostheses

2021 ◽  
Vol 16 ◽  
Author(s):  
Keerti Rajput ◽  
Karan Veer
Keyword(s):  
Lower Limb ◽  
Confusion Matrix ◽  
Support Vector ◽  
Semg Signal ◽  
Linear Discriminant ◽  
Network Support ◽  
Recorded Data ◽  
Non Stationary Signal ◽  
Semg Signals ◽  
Lower Limb Prostheses

Aim: On multiple muscle locations, surface electromyography (sEMG) signals were recorded to predict the effect of different hand movements. Background: Myoelectric information is a non-stationary signal, so extracting correct features is important to boost any myoelectric control devices' performance. The myoelectric signal is an electrical activity recorded by a surface electrode at various movements of the muscles. Objective: The study presented pattern recognition classification methods to select an excellent algorithm for controlling the SEMG signal. Method: Various time domain and frequency domain parameters were extracted prior to conduct the classifier test. Result: For the evaluation of the results for the recorded data (of all six movements), confusion matrix for neural network, support vector machine (SVM), DT, and linear discriminant analysis (LDA) classifiers is presented. Conclusion: This present study will be a step in analyzing different problems for developing lower limb prostheses.

scholarly journals A Prototype SSVEP Based Real Time BCI Gaming System

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Ignas Martišius ◽  
Robertas Damaševičius
Keyword(s):  
Support Vector Machine ◽  
Support Vector Machine Classifier ◽  
Brain Computer Interface ◽  
Computer Interface ◽  
Support Vector ◽  
Disabled People ◽  
Linear Discriminant ◽  
Average Accuracy ◽  
Wave Atom Transform ◽  
Linear Discriminant Analysis Classifier

Although brain-computer interface technology is mainly designed with disabled people in mind, it can also be beneficial to healthy subjects, for example, in gaming or virtual reality systems. In this paper we discuss the typical architecture, paradigms, requirements, and limitations of electroencephalogram-based gaming systems. We have developed a prototype three-class brain-computer interface system, based on the steady state visually evoked potentials paradigm and the Emotiv EPOC headset. An online target shooting game, implemented in the OpenViBE environment, has been used for user feedback. The system utilizes wave atom transform for feature extraction, achieving an average accuracy of 78.2% using linear discriminant analysis classifier, 79.3% using support vector machine classifier with a linear kernel, and 80.5% using a support vector machine classifier with a radial basis function kernel.

Hygienic assessment of working conditions working in LLC “Oil and gas equipment plant»

2020 ◽  
pp. 733-733
Author(s):  
V. P. Rodkin ◽  
A. N. Usatov ◽  
V. G. Demchenko
Keyword(s):  
Working Conditions ◽  
Oil And Gas ◽  
Preventive Measures ◽  
Working Environment

The authors conducted a hygienic assessment of working conditions of employees in LLC «Oil and gas equipment plant» on the basis of research of the Center of Hygiene and Epidemiology in the Omsk region. The factors of the working environment and working conditions of workers having an impact on their health. Are studied. Hygiene-based preventive measures have been developed.

Hygienic aspects of working conditions of workers in the Samara region

2020 ◽  
pp. 564-564
Author(s):  
N. S. Belyakova ◽  
N. M. Tsunina ◽  
A. S. Karapetyan
Keyword(s):  
Working Conditions ◽  
Female Body ◽  
Working Environment ◽  
Working Day

The factors of working conditions that affect the health of women during the working day are listed. Developed measures to create a favorable working environment for the female body.

An occupational hazard of workers of wagon-repair production

2019 ◽  
pp. 272-277 ◽  
Author(s):  
Galina V. Kurenkova ◽  
Natalia A. Sudeikina ◽  
Elizaveta P. Lemeshevskaya
Keyword(s):  
Working Conditions ◽  
Musculoskeletal System ◽  
Occupational Risk ◽  
Working Environment ◽  
Labor Process ◽  
Control Group ◽  
Professional Groups ◽  
Wagon Wheel ◽  
Medical Examinations ◽  
Very High

Introduction. Professional groups of railway workers engaged in the repair of wagons are directly responsible for the safety of railway traffic. The analysis of literature testifies to insufficient attention of researchers to the hygienic problems associated with labor activity of workers of wagon-repair production.The aim of the study is to assess the occupational risk to the health of wagon repair workers, due to the impact on them of factors of the working environment and the labor process.Materials and methods. The study used comprehensive hygienic studies using the methodology of occupational risk to worker’s health.Results. The leading factors of the working environment (class of working conditions 3.2–3.4), which are exposed to workers depending on the specifics of the work performed. Identified professional groups with medium (significant) high (unbearable) and very high (intolerable) category of a priori occupational risk: in wagon meintenance workshop — 17 groups (94% of jobs), in a wagon assembly workshop — 11 groups (80% jobs), in wagon wheel workshop — 3 group (100% jobs). At the same time, according to the request for medical care, employees were diagnosed with isolated cases of occupational diseases.The levels of morbidity with temporary disability of employees of the main workshops are statistically significant (p<0.05) higher than those of the control group in 1.4–1.9 times. The influence of the complex of chemical factors of low and medium intensity on the levels of morbidity of respiratory diseases in the group of workers of the wagon wheel workshop, which were 1.7–2.0 times higher than in the control group, is confirmed by the average degree of causation of the production condition of this pathology (RR=1.7; EF=42.0%).The combined effect of vibration and severity of the labor process forms a high level of temporary disability of employees of the main workshops in connection with diseases of the musculoskeletal system, which was 2.7–4.4 times higher than in the control group, and also determines the prevalence of this pathology in the structure of diseases detected on medical examinations (23.2%). Diseases of the musculoskeletal system are caused by the production of employees of the wagon meintenance workshop (RR=3,9; EF=74,9%), as the most unfavorable in terms of hygiene on these factors.The stressful influence of the complex of harmful production factors on the health of wagon repair workers is manifested by the high risk of diseases of the cardiovascular system, gastrointestinal tract, neurological disorders, violation of adaptation of the cardiovascular system in 97% of the examined, as well as the predominance of diseases of the digestive system and circulatory system detected on periodic medical examinations.Conclusions. Harmful working conditions (class 3.1–3.4) cause the suspected occupational risk from small (moderate) to very high (intolerable) to 100% of the jobs of wagon repair workers. The results of the study of morbidity and risk of pathology indicate a significant risk of damage to the health of workers.

A ROBUST AND FRIENDLY HUMAN–ROBOT INTERFACE SYSTEM BASED ON NATURAL HUMAN GESTURES

2010 ◽  
Vol 24 (06) ◽  
pp. 847-866 ◽  
Author(s):  
MING-SHAUNG CHANG ◽  
JUNG-HUA CHOU
Keyword(s):  
Real Time ◽  
Face Detection ◽  
Fuzzy Logic Controller ◽  
Tracking System ◽  
Back Propagation ◽  
Principal Component ◽  
Working Environment ◽  
Expression Recognition ◽  
Linear Discriminant ◽  
Human Gestures

In this paper, we design a robust and friendly human–robot interface (HRI) system for our intelligent mobile robot based only on natural human gestures. It consists of a triple-face detection method and a fuzzy logic controller (FLC)-Kalman filter tracking system to check the users and predict their current position in a dynamic and cluttered working environment. In addition, through the combined classifier of the principal component analysis (PCA) and back-propagation artificial neural network (BPANN), single and successive commands defined by facial positions and hand gestures are identified for real-time command recognition after dynamic programming (DP). Therefore, the users can instruct this HRI system to make member recognition or expression recognition corresponding to their gesture commands, respectively based on the linear discriminant analysis (LDA) and BPANN. The experimental results prove that the proposed HRI system perform accurately in real-time face detection and tracking, and robustly react to the corresponding gesture commands at eight frames per second (fps).

scholarly journals Fabric Vest Socket with Embroidered Electrodes for Control of Myoelectric Prosthesis

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1196 ◽  
Author(s):  
Seulah Lee ◽  
Babar Jamil ◽  
Sunhong Kim ◽  
Youngjin Choi
Keyword(s):  
Signal To Noise Ratio ◽  
Cost Effective ◽  
Electrode Impedance ◽  
Rigid Support ◽  
Daily Lives ◽  
Myoelectric Prosthesis ◽  
Myoelectric Prostheses ◽  
Average Classification Accuracy ◽  
High Level ◽  
Semg Signals

Myoelectric prostheses assist users to live their daily lives. However, the majority of users are primarily confined to forearm amputees because the surface electromyography (sEMG) that understands the motion intents should be acquired from a residual limb for control of the myoelectric prosthesis. This study proposes a novel fabric vest socket that includes embroidered electrodes suitable for a high-level upper amputee, especially for shoulder disarticulation. The fabric vest socket consists of rigid support and a fabric vest with embroidered electrodes. Several experiments were conducted to verify the practicality of the developed vest socket with embroidered electrodes. The sEMG signals were measured using commercial Ag/AgCl electrodes for a comparison to verify the performance of the embroidered electrodes in terms of signal amplitudes, the skin-electrode impedance, and signal-to-noise ratio (SNR). These results showed that the embroidered electrodes were as effective as the commercial electrodes. Then, posture classification was carried out by able-bodied subjects for the usability of the developed vest socket. The average classification accuracy for each subject reached 97.92%, and for all the subjects it was 93.2%. In other words, the fabric vest socket with the embroidered electrodes could measure sEMG signals with high accuracy. Therefore, it is expected that it can be readily worn by high-level amputees to control their myoelectric prostheses, as well as it is cost effective for fabrication as compared with the traditional socket.

scholarly journals Suddenly Telework: Job Crafting as a Way to Promote Employee Well-Being?

2022 ◽  
Vol 12 ◽  
Author(s):  
Christiane R. Stempel ◽  
Katja Siestrup
Keyword(s):  
Working Conditions ◽  
Online Survey ◽  
Well Being ◽  
Job Characteristics ◽  
Social Resources ◽  
Working Environment ◽  
Job Crafting ◽  
Advantages And Disadvantages ◽  
Abrupt Shift ◽  
Quantitative Results

COVID-19 confronted many people with an abrupt shift from their usual working environment to telework. This study explores which job characteristics are perceived as most crucial in this exceptional situation and how they differ from people’s previous working conditions. Additionally, we focus on job crafting as a response to this situation and how it is related to employees’ well-being. We conducted an online survey with N = 599 participants, of which 321 reported that they were telework newcomers. First, we asked participants to indicate the three most important advantages and disadvantages they see in telework. The subsequent questionnaire contained a comprehensive measure of working conditions before and during the pandemic, job crafting behaviors, and indicators of well-being. Based on the qualitative answers, we identified three major advantages and disadvantages. Quantitative results indicate perceived changes in all job characteristics for telework newcomers. Concerning working conditions and well-being, job crafting activities that aim to increase structural and social resources are important mediators. The findings underline the need to design appropriate telework conditions and encourage job crafting activities to foster occupational well-being.

scholarly journals Research on Rolling Bearing Fault Feature Extraction and Diagnosis Method Based on Image Processing

2021 ◽  
Vol 5 (2) ◽  
pp. 1-7
Author(s):  
Sun Y
Keyword(s):  
Image Processing ◽  
Feature Extraction ◽  
Working Conditions ◽  
Rolling Bearing ◽  
Extraction Methods ◽  
Working Environment ◽  
Ring Rolling ◽  
Rolling Bearings ◽  
Binary Matrix ◽  
The Time Domain

In economic construction, there are many large and important machinery and equipment. Some equipment will continue to work in a harsh working environment, so many and various failures will occur. Rolling bearings are one of the widely used parts in rotating machinery. They are generally composed of inner ring, outer ring, rolling element and holding. The frame is composed of four parts, the failure of the bearing is particularly important, and its safe operation has a vital impact on the entire equipment, Feature extraction is the key link in the subsequent identification of fault types, Although feature extraction in the time domain and frequency domain is effective, it is also necessary to find new feature extraction methods in new areas. On the basis of the snowflake image obtained by using the principle of SDP(Symmetrized Dot Pattern), a method for extracting fault features of rolling bearings based on image processing is proposed, and the snowflake standard map for different working conditions is constructed. The number of snowflake images under different working conditions is different. The binary matrix of the test image is compared with it, and then classified and identified. Finally, the algorithm is validated, and the ideal result is obtained to verify its rationality and effectiveness.

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