Motor Imagination of Lower Limb Movements at Different Frequencies

Motor imagination (MI) is the mental process of only imagining an action without an actual movement. Research on MI has made significant progress in feature information detection and machine learning decoding algorithms, but there are still problems, such as a low overall recognition rate and large differences in individual execution effects, which make the development of MI run into a bottleneck. Aiming at solving this bottleneck problem, the current study optimized the quality of the MI original signal by “enhancing the difficulty of imagination tasks,” conducted the qualitative and quantitative analyses of EEG rhythm characteristics, and used quantitative indicators, such as ERD mean value and recognition rate. Research on the comparative analysis of the lower limb MI of different tasks, namely, high-frequency motor imagination (HFMI) and low-frequency motor imagination (LFMI), was conducted. The results validate the following: the average ERD of HFMI (−1.827) is less than that of LFMI (−1.3487) in the alpha band, so did (−3.4756 < −2.2891) in the beta band. In the alpha and beta characteristic frequency bands, the average ERD of HFMI is smaller than that of LFMI, and the ERD values of the two are significantly different ( p = 0.0074 < 0.01 ; r = 0.945). The ERD intensity STD values of HFMI are less than those of LFMI. which suggests that the ERD intensity individual difference among the subjects is smaller in the HFMI mode than in the LFMI mode. The average recognition rate of HFMI is higher than that of LFMI (87.84% > 76.46%), and the recognition rate of the two modes is significantly different ( p = 0.0034 < 0.01 ; r = 0.429). In summary, this research optimizes the quality of MI brain signal sources by enhancing the difficulty of imagination tasks, achieving the purpose of improving the overall recognition rate of the lower limb MI of the participants and reducing the differences of individual execution effects and signal quality among the subjects.

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Analysis and Recognition of Human Lower Limb Motions Based on Electromyography (EMG) Signals

Electronics ◽

10.3390/electronics10202473 ◽

2021 ◽

Vol 10 (20) ◽

pp. 2473

Author(s):

Junyao Wang ◽

Yuehong Dai ◽

Xiaxi Si

Keyword(s):

Neural Network ◽

Bp Neural Network ◽

Lower Limb ◽

Recognition Rate ◽

Measurement Unit ◽

Lower Limb Muscles ◽

Average Recognition Rate ◽

Standing Up ◽

Length Data ◽

Hidden Layer

Background: This paper focuses on the characteristics of lower limb EMG signals for common movements. Methods: We obtained length data for lower limb muscles during gait motion using software named OpenSim; statistical product and service solutions (SPSS) were utilized to study the correlation between each muscle, based on gait data. Low-correlation muscles in different regions were selected; inertial measurement unit (IMU) and EMG sensors were used to measure the lower limb angles and EMG signals when on seven kinds of slope, in five kinds of gait (walking on flat ground, uphill, downhill, up-step and down-step) and four kinds of movement (squat, lunge, raised leg and standing up). Results: After data denoising and feature extraction, we designed a double hidden-layer BP neural network to recognize the above motions according to EMG signals. Results show that EMG signals of selected muscles have a certain periodicity in the process of movement that can be used to identify lower limb movements. Conclusions: It can be seen, after the recognition of different proportions of training and testing sets that the average recognition rate of the BP neural network is 86.49% for seven gradients, 93.76% for five kinds of gait and 86.07% for four kinds of movements.

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Dynamics of the processes in metal machining

Nonlinear Analysis Modelling and Control ◽

10.15388/na.1998.2.0.15295 ◽

1998 ◽

Vol 2 ◽

pp. 115-122

Author(s):

Donatas Švitra ◽

Jolanta Janutėnienė

Keyword(s):

High Frequency ◽

Machine Tools ◽

Metal Cutting ◽

Cutting Tool ◽

Low Frequency ◽

Metal Cutting Machine ◽

Cutting Machine ◽

Metal Machining

In the practice of processing of metals by cutting it is necessary to overcome the vibration of the cutting tool, the processed detail and units of the machine tool. These vibrations in many cases are an obstacle to increase the productivity and quality of treatment of details on metal-cutting machine tools. Vibration at cutting of metals is a very diverse phenomenon due to both it’s nature and the form of oscillatory motion. The most general classification of vibrations at cutting is a division them into forced vibration and autovibrations. The most difficult to remove and poorly investigated are the autovibrations, i.e. vibrations arising at the absence of external periodic forces. The autovibrations, stipulated by the process of cutting on metalcutting machine are of two types: the low-frequency autovibrations and high-frequency autovibrations. When the low-frequency autovibration there appear, the cutting process ought to be terminated and the cause of the vibrations eliminated. Otherwise, there is a danger of a break of both machine and tool. In the case of high-frequency vibration the machine operates apparently quiently, but the processed surface feature small-sized roughness. The frequency of autovibrations can reach 5000 Hz and more.

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Estimating the Quality of Thermionic Cathodes for Microwave Vacuum Tubes Using the Low-Frequency Noise Parameters

Vestnik MEI ◽

10.24160/1993-6982-2018-5-120-127 ◽

2018 ◽

Vol 5 (5) ◽

pp. 120-127

Author(s):

Mikhail D. Vorobyev ◽

◽

Dmitriy N. Yudaev ◽

Andrey Yu. Zorin ◽

◽

...

Keyword(s):

Low Frequency ◽

Frequency Noise ◽

Low Frequency Noise ◽

Noise Parameters ◽

Thermionic Cathodes ◽

Vacuum Tubes

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Changes in the Total Power of Beta and Theta Bands When Using EEG Biofeedback in Primary School-Age Children Having Difficulties with Voluntary Regulation

Journal of Medical and Biological Research ◽

10.37482/2687-1491-z025 ◽

2020 ◽

pp. 331-340

Author(s):

Yuliya S. Dzhos ◽

◽

Irina A. Men’shikova ◽

Keyword(s):

Left Hemisphere ◽

Spectral Characteristics ◽

Low Frequency ◽

School Age Children ◽

Total Power ◽

Eeg Biofeedback ◽

Beta Band ◽

Bioelectric Activity ◽

Voluntary Regulation ◽

The Brain

This article presents the results of the study on spectral electroencephalogram (EEG) characteristics in 7–10-year-old children (8 girls and 22 boys) having difficulties with voluntary regulation of activity after 10 and 20 neurofeedback sessions using beta-activating training. Brain bioelectric activity was recorded in 16 standard leads using the Neuron-Spectrum-4/VPM complex. The dynamics was assessed by EEG beta and theta bands during neurofeedback. An increase in the total power of beta band oscillations was established both after 10 and after 20 sessions of EEG biofeedback in the frontal (p ≤ 0.001), left parietal (p ≤ 0.036), and temporal (p ≤ 0.003) areas of the brain. A decrease in the spectral characteristics of theta band oscillations was detected: after 10 neurofeedback sessions in the frontal (p ≤ 0.008) and temporal (p ≤ 0.006) areas of both hemispheres, as well as in the parietal area of the left hemisphere (p ≤ 0.005); after 20 sessions, in the central (p ≤ 0.004), frontal (p ≤ 0.001) and temporal (p ≤ 0.001) areas of both hemispheres, as well as in the occipital (p ≤ 0.047) and parietal (p ≤ 0.001) areas of the left hemisphere. The study into the dynamics of bioelectric activity during biofeedback using EEG parameters in 7–10-year-old children with impaired voluntary regulation of higher mental functions allowed us to prove the advisability of 20 sessions, as the increase in high-frequency activity and decrease in low-frequency activity do not stop with the 10th session. Changes in these parameters after 10 EEG biofeedback sessions are expressed mainly in the frontotemporal areas of both hemispheres, while after a course of 20 sessions, in both the frontotemporal and central parietal areas of the brain.

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State-of-the-Art: A Systematic Literature Review on Image Segmentation in Latent Fingerprint Forensics

Recent Patents on Computer Science ◽

10.2174/2213275912666190429153952 ◽

2019 ◽

Vol 12 ◽

Cited By ~ 2

Author(s):

Megha Chhabra ◽

Manoj Kumar Shukla ◽

Kiran Kumar Ravulakollu

Keyword(s):

Image Segmentation ◽

Background Noise ◽

State Of The Art ◽

Recognition Rate ◽

Poor Quality ◽

Latent Fingerprint ◽

In The Beginning ◽

The Comparative Study ◽

Finger Skin

: Latent fingerprints are unintentional finger skin impressions left as ridge patterns at crime scenes. A major challenge in latent fingerprint forensics is the poor quality of the lifted image from the crime scene. Forensics investigators are in permanent search of novel outbreaks of the effective technologies to capture and process low quality image. The accuracy of the results depends upon the quality of the image captured in the beginning, metrics used to assess the quality and thereafter level of enhancement required. The low quality of the image collected by low quality scanners, unstructured background noise, poor ridge quality, overlapping structured noise result in detection of false minutiae and hence reduce the recognition rate. Traditionally, Image segmentation and enhancement is partially done manually using help of highly skilled experts. Using automated systems for this work, differently challenging quality of images can be investigated faster. This survey amplifies the comparative study of various segmentation techniques available for latent fingerprint forensics.

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Economic assessment of a community-based care package for people with lower limb disorder caused by lymphatic filariasis, podoconiosis and leprosy in Ethiopia

Transactions of the Royal Society of Tropical Medicine and Hygiene ◽

10.1093/trstmh/traa111 ◽

2020 ◽

Vol 114 (12) ◽

pp. 1021-1034

Author(s):

Natalia Hounsome ◽

Mersha Kinfe ◽

Maya Semrau ◽

Oumer Ali ◽

Abraham Tesfaye ◽

...

Keyword(s):

Quality Of Life ◽

Lymphatic Filariasis ◽

Lower Limb ◽

Life Quality ◽

Psychosocial Care ◽

Northwest Ethiopia ◽

World Health ◽

Care Package ◽

The Cost

Abstract We conducted an implementation research study to integrate a holistic package of physical health, mental health and psychosocial care for podoconiosis, lymphatic filariasis and leprosy into routine healthcare in Gusha cluster, Guagusa Shikudad district, northwest Ethiopia. The healthcare package included training patients in lower limb hygiene and skin care and provision of shoes, hygiene supplies and medication. The implementation activities included training events, workshops, awareness raising, self-help groups, supportive supervision, staff secondments and advisory board meetings. The cost of implementing the care package in Gusha cluster, with a population of 30 558 people, was 802 655 Ethiopian birr (ETB) (£48 159) and the cost of delivering care to 235 participants was 204 388 ETB (£12 263), or 870 ETB (£52) per person. There was a 35% decrease in the mean disability scores (measured using the World Health Organization Disability Assessment Schedule 2.0) and a 45% improvement in the dermatology-specific quality of life (measured using the Dermatology Life Quality Index) at the 3-month follow-up compared with baseline. There were reductions in the number of days with symptoms, days off usual activities/work and days with reduced activity due to illness, all of which were statistically significant. Our pilot suggests that integration of the care package into routine healthcare in Ethiopia may be effective in improving health-related quality of life and disability and reducing time out of economic activity due to illness.

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Supranational Assessment of the Quality of Probiotics: Collaborative Initiative between Independent Accredited Testing Laboratories

Microorganisms ◽

10.3390/microorganisms9071456 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1456

Author(s):

Jean-Pol Warzée ◽

Marina Elli ◽

Abdoulaye Fall ◽

Daniela Cattivelli ◽

Jean-Yves François

Keyword(s):

Daily Basis ◽

Qualitative Assessment ◽

Close Collaboration ◽

Quality Label ◽

Accredited Laboratories ◽

Quantitative Analyses ◽

Quality Of Food ◽

The Eu

Recent acquisitions about the role of the microbiota in the functioning of the human body make it possible to envisage an increasing use of beneficial microbes, and more particularly of probiotics as well as their metabolites, as nutritional supplements. National and EU authorities are engaged in assuring the safety and quality of food supplements and in defining rules to assess and communicate their efficacy on human health. The quality of probiotics, intended as strains’ identification, viability, and stability over time, is a crucial factor of credibility with consumers and health professionals. Analytical technologies for the quality control of probiotics must also be adapted to new preparations, such as those including new multistrains complex combinations. Accredited laboratories face this relevant challenge on a daily basis. Through its close collaboration with the laboratory commissioned to produce the specifications for its ESLP quality label (identification and quantitative analyses) together with its scientific committee, the ESLP has been focusing on this issue for 10 years. Recently, as part of the internationalization of the ESLP quality label, a new and unique initiative in Europe for the evaluation of the quality of probiotic preparations has been carried out. The collaboration between two accredited laboratories in Belgium and in Italy represented a concrete example of supranational collaboration in the assessment of the quality of probiotic preparations. Results show that both laboratories are in line as expected in terms of performance. Common approaches to the qualitative assessment of probiotic preparations, especially for complex and composite recipes, in terms of number of strains and included substances, should be encouraged and promoted all over the EU.

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The association between Helicobacter pylori and obesity: a systematic review and meta-analysis of case–control studies

Clinical Diabetes and Endocrinology ◽

10.1186/s40842-021-00131-w ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Ali Baradaran ◽

Hojat Dehghanbanadaki ◽

Sara Naderpour ◽

Leila Mohammadi Pirkashani ◽

Abdolhalim Rajabi ◽

...

Keyword(s):

Odds Ratio ◽

Meta Analysis ◽

Pooled Analysis ◽

Case Control ◽

Case Control Studies ◽

Newcastle Ottawa Scale ◽

Prevalence Of Obesity ◽

Quantitative Analyses ◽

H Pylori

Abstract Introduction The relationship between H. pylori infection and obesity development has remained controversial among various studies. The aim of this study was to clarify the pooled effect of H. pylori infection on the development of obesity and vice versa. Methods We searched international databases including Medline (PubMed), Web of sciences, Scopus, EMBASE, Cochrane, Ovid, and CINHAL to retrieve all case–control studies reporting the effect of H. pylori on obesity and vice versa, which had been published in English between January 1990 and June 2019. The quality of included studies was assessed by the Modified Newcastle–Ottawa Scale for Case–Control studies. The logarithm of the odds ratio (OR) and its standard error was used for the meta-analysis. Results Eight case–control studies with 25,519 participants were included for qualitative and quantitative analyses. The pooled analysis showed that obese participants had a higher risk of H. pylori infection than lean participants with an odds ratio of 1.46 (95%CI: 1.26, 1.68). Also, the pooled analysis revealed that participants infected by H. pylori had a higher risk of obesity than non-infected participants with an odds ratio of 1.01 (95%CI: 1.01, 1.02). Conclusion The results of this meta-analysis showed that there was a positive correlation between the risk of H. pylori infection and the prevalence of obesity development. Thus, H. pylori positive patients were more likely to be obese, and obese individuals had higher risks of H. pylori infection.

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Non-Intrusive Load Disaggregation Based on a Multi-Scale Attention Residual Network

Applied Sciences ◽

10.3390/app10249132 ◽

2020 ◽

Vol 10 (24) ◽

pp. 9132

Author(s):

Liguo Weng ◽

Xiaodong Zhang ◽

Junhao Qian ◽

Min Xia ◽

Yiqing Xu ◽

...

Keyword(s):

Smart Grids ◽

Recognition Rate ◽

Low Frequency ◽

Attention Mechanism ◽

Learning Ability ◽

Residual Network ◽

Multi Scale ◽

Energy Disaggregation ◽

Benchmark Datasets ◽

Load Disaggregation

Non-intrusive load disaggregation (NILD) is of great significance to the development of smart grids. Current energy disaggregation methods extract features from sequences, and this process easily leads to a loss of load features and difficulties in detecting, resulting in a low recognition rate of low-use electrical appliances. To solve this problem, a non-intrusive sequential energy disaggregation method based on a multi-scale attention residual network is proposed. Multi-scale convolutions are used to learn features, and the attention mechanism is used to enhance the learning ability of load features. The residual learning further improves the performance of the algorithm, avoids network degradation, and improves the precision of load decomposition. The experimental results on two benchmark datasets show that the proposed algorithm has more advantages than the existing algorithms in terms of load disaggregation accuracy and judgments of the on/off state, and the attention mechanism can further improve the disaggregation accuracy of low-frequency electrical appliances.

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Lower Limb Kinematics in Individuals with Hip Osteoarthritis during Gait: A Focus on Adaptative Strategies and Interlimb Symmetry

Bioengineering ◽

10.3390/bioengineering8040047 ◽

2021 ◽

Vol 8 (4) ◽

pp. 47

Author(s):

Micaela Porta ◽

Massimiliano Pau ◽

Bruno Leban ◽

Michela Deidda ◽

Marco Sorrentino ◽

...

Keyword(s):

Lower Limb ◽

Functional Limitations ◽

Hip Osteoarthritis ◽

Movement Analysis ◽

Human Movement ◽

Point Of View ◽

Negative Effects ◽

Gait Patterns ◽

Limb Kinematics

Among the functional limitations associated with hip osteoarthritis (OA), the alteration of gait capabilities represents one of the most invalidating as it may seriously compromise the quality of life of the affected individual. The use of quantitative techniques for human movement analysis has been found valuable in providing accurate and objective measures of kinematics and kinetics of gait in individuals with hip OA, but few studies have reported in-depth analyses of lower limb joint kinematics during gait and, in particular, there is a scarcity of data on interlimb symmetry. Such aspects were investigated in the present study which tested 11 individuals with hip OA (mean age 68.3 years) and 11 healthy controls age- and sex-matched, using 3D computerized gait analysis to perform point-by-point comparisons of the joint angle trends of hip, knee, and ankle. Angle-angle diagrams (cyclograms) were also built to compute several parameters (i.e., cyclogram area and orientation and Trend Symmetry) from which to assess the degree of interlimb symmetry. The results show that individuals with hip OA exhibit peculiar gait patterns characterized by severe modifications of the physiologic trend at hip level even in the unaffected limb (especially during the stance phase), as well as minor (although significant) alterations at knee and ankle level. The symmetry analysis also revealed that the effect of the disease in terms of interlimb coordination is present at knee joint as well as hip, while the ankle joint appears relatively preserved from specific negative effects from this point of view. The availability of data on such kinematic adaptations may be useful in supporting the design of specific rehabilitative strategies during both preoperative and postoperative periods.

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