Ali Maleki

Ali Maleki
Semnan University · Biomedical Engineering Department

PhD

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88
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Introduction
Skills and Expertise

Publications

Publications (88)
Article
Full-text available
Background Gait initiation (GI) can be divided into three sections according to the center of pressure (COP) trace (S1, S2, and S3). Almost all studies do not separate each phase of the GI profile in postural control assessment and muscular investigation, whereas differences in the COP and muscles are found in each phase of the GI profile in people...
Article
Full-text available
Background and Aims Gait initiation (GI) in individuals with chronic ankle instability (CAI) has shown differences in the center of pressure (COP) and muscular measures compared to healthy controls. Some studies reported that these alterations appeared when GI was with the affected leg, while others indicated that they occurred when GI was with the...
Article
Full-text available
Background Autism spectrum disorders are a type of developmental disorder that primarily disrupt social interactions and communications. Autism has no treatment, but early diagnosis of it is crucial to reduce these effects. The incidence of autism is represented in repetitive patterns of children’s motion. When walking, these children tighten their...
Article
Full-text available
Background A key challenge in steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) systems is to effectively recognize frequencies within a short time window. To address this challenge, the specific characteristics of the data are needed to select the frequency recognition method. These characteristics include factors,...
Article
Full-text available
This study comprehensively assesses various recurrent neural networks (RNNs) for decoding the elbow angle from electromyogram (EMG) signals, a crucial aspect in myoelectric interfaces. EMG signals from the shoulder girdle and arm were recorded during goal-directed reaching movements, and linear envelopes were continuously mapped to the elbow angle...
Article
Full-text available
Background To enhance the information transfer rate (ITR) of a steady-state visual evoked potential (SSVEP)-based speller, more characters with flickering symbols should be used. Increasing the number of symbols might reduce the classification accuracy. A hybrid brain-computer interface (BCI) improves the overall performance of a BCI system by taki...
Article
Full-text available
Background Fatigue is a serious challenge when applying a steady-state visual evoked potential (SSVEP)-based brain-computer interfaces (BCIs) in the real world. Many researchers have used quantitative indices to study the effect of visual stimuli on fatigue. According to a wide range of studies in fatigue analysis, there are contradictions and inco...
Article
Steady-state visual evoked potential (SSVEP) is the brain's response to quickly repetitive visual stimulus with a certain frequency. To increase the information transfer rate (ITR) in SSVEP-based systems, due to the frequency resolution restriction, we are forced to broaden the frequency range, which causes harmonic frequencies to come into the sti...
Article
Background: The empirical mode decomposition (EMD) is a technique to analyze the steady-state visual evoked potential (SSVEP) which decomposes the signal into its intrinsic mode functions (IMFs). Although for the limited stimulation frequency range, choosing the effective IMF leads to good results, but extending this range will seriously challenge...
Article
Brain-Computer Interface (BCI) is a system that enables users to transmit commands to the computer using their brain activity recorded by electroencephalography. In a Hybrid Brain-Computer Interface (HBCI), a BCI control signal combines with one or more BCI control signals or with Human-Machine Interface (HMI) biosignals to increase classification...
Article
Full-text available
Background and Aims Since gait disorder is the most common complication among patients with multiple sclerosis. This study aims to examine the effect of hippotherapy on the onset activity of selected lower limb muscles in patients with multiple sclerosis (MS) during the gait initiation protocol with a perturbation response approach. Methods A total...
Article
BCI systems provide a direct communication channel between the human and the machine using brain signals. Among the various methods of steady-state visual evoked potential (SSVEP) stimulation frequency detection, multiple linear regression (MLR), and multiset canonical correlation analysis (MsetCCA) methods have achieved high accurate results in re...
Article
Full-text available
Muscle synergies have been hypothesized as specific predefined motor primitives that the central nervous system can reduce the complexity of motor control by using them, but how these are expressed in brain activity is ambiguous yet. The main purpose of this paper is to develop synergy-based neural decoding of motor primitives, so for the first tim...
Article
The use of hybrid brain–computer interface (HBCI) systems have received much attention in recent years. However, there are few published datasets for HBCI systems. This paper provides a benchmark dataset for these systems. The provided dataset consist of data corresponding to three speller systems, including SSVEP-based BCI system and HBCI systems...
Article
Full-text available
Brain-computer interface (BCI) systems can be used to communicate and express desires from people with severe nervous system damage. Among BCI systems based on evoked responses, steady state visual evoked potential (SSVEP) responses are the most widely used. Canonical correlation analysis (CCA)-based methods have been widely used in SSVEP-based onl...
Article
Introduction Estimation of reaching movement commands for controlling human–machine interfaces (HMIs) based on electromyogram (EMG) signals, such as prostheses or robotic assistive devices, for the disabled is challenging due to the absence of healthy and synergistic muscle activations. Methods In this study, to improve the kinematic estimation of...
Article
Full-text available
Objectives: Whole-Body Vibration (WBV) exercise seems to be an effective alternative to improve physical performance in the elderly. This study aims to compare the effects of eight weeks of WBV exercise combined with rope skipping at two different intensities on physical performance of older men. Methods & Materials: This is a randomized single-bli...
Article
Full-text available
The aim of the present study was to analyze the effects of ballistic and power training on table tennis players’ electromyography (EMG) changes. Thirty male table tennis players, who were able to perform top spin strikes properly, were randomly assigned to three groups: power training (PT; n = 10); ballistic training (BT; n = 10); and no training (...
Article
Stress endangers the mental and physical health of individuals and also has a major impact on society. Accurate, reliable and quantitative measurement of stress leads to detect the person’s stress level in earlier stages and reduce the intervention time to manage it. Individuals’ stress gradually changes from one level to another. That’s why tradit...
Article
The surface electromyogram (sEMG) of amputees’ remnant muscles can be an appropriate candidate to estimate clinical parameters, such as DASH (disabilities of the arm, shoulder, and hand) score or PLSI (phantom limb sensation intensity) automatically which can be used instead of the patients’ self-report or specialist assessments. In this study, to...
Article
Full-text available
Electrogoniometers are low price sensors which are easily attached to the body in any environment. Although electrogoniometer sensors are typically used for angular measurements, they can also be used to determine position. This study aimed to accurately determine hand position during the performance of five daily life activities using two electrog...
Article
Full-text available
The purpose of this study was to examine the effects of ballistic and power training on the skills, physical fitness and body composition adaptations of élite table tennis players. Thirty male table tennis players (age: 24 ± 7 years, stature: 175 ± 6 cm, body mass 74 ± 16 kg, percentage of fat mass (%FM) 12 ± 7%, mean ± SD), who were able to perfor...
Article
Objective EEG-based motion trajectory decoding makes a promising approach for neurotechnology which can be used for neural control of motion reconstruction and neurorehabilitation tools. However, the feasibility and validity of continuous motion decoding by non-invasive brain activity are not clear. The main aim of this study was to perform a meta-...
Presentation
Introduction: This research seeks to shed lights on the possible effects of bilingualism on visuospatial short-term memory(VSTM)and tries to expand our knowledge of how it will be affected and may differ based on anodal and cathodal transcranial direct current stimulation (tDCS) on it. Methods: 164 healthy young(64 monolinguals, and 64 bilinguals)a...
Article
Full-text available
The present study aimed to develop a realistic model for the generation of human activities of daily living (ADL) movements. The angular profiles of the elbow joint during functional ADL tasks such as eating and drinking were generated by a submovement-based closed-loop model. First, the ADL movements recorded from three human participants were bro...
Article
The reliability of electrogoniometers as wearable sensors depends on the biomechanical characteristics of the human body. The major causes of electrogoniometric measurement errors are the complexity of movements and the anatomical features of joints. Accordingly, the main objective of this study is to enhance goniometric measurements of body kinema...
Article
Background and Objective In recent years, stress and mental health have been considered as important worldwide concerns. Stress detection using physiological signals such as electrocardiogram (ECG), skin conductance (SC), electromyogram (EMG) and electroencephalogram (EEG) is a traditional approach. However, the effect of stress on the EMG signal o...
Article
Objective Steady-state visual evoked potential (SSVEP) is a control signal which is widely used in brain-computer interface (BCI) systems. The SSVEP-based spellers with hierarchical structure have a limitation of low ITR. To improve the ITR in these spellers, we effectively applied the character encoding based on the character frequency rate. Meth...
Article
Background BCI systems based on steady-state visual evoked potentials (SSVEP) have formed an immense contribution to practical applications, due to their high recognition accuracy and ease of use. The MLR method has a better frequency recognition accuracy for short-term windows, and the MsetCCA method works more accurately in long-term windows. Ne...
Article
Investigation of long memory processes in signals can give us an important information about how signals have behaved so far and how will it behave in future. Hurst exponent estimation is a proper tool to show memory in signals. Rescaled range analysis (R/S), detrended fluctuation analysis (DFA) and generalized Hurst exponent (GHE) are most known m...
Article
Central nervous system (CNS) uses the combination of a small number of motor primitives, named muscle synergies, for simplification of motor control in human movement. The aim of this study was to investigate the muscle coordination in both leg muscles during pedaling by time-varying muscle synergy extraction. Twenty healthy subjects performed thre...
Article
Objectives: The present study aimed to evaluate the evidence related to the effect of upper limb motor recovery on submovement characteristics, including duration, amplitude, overlap, interpeak distance, and the number of submovements in stroke patients using a meta-analysis. Literature survey: The literature search was restricted to articles wr...
Article
Objective The common criteria for evaluating the performance of the brain–computer interface (BCI) are classification accuracy and information transfer rate (ITR). Due to the fact that the BCI system has direct interaction with patients, the accuracy of estimated ITR is very influential. Although the most popular method for ITR estimation is the Wo...
Article
Muscle synergies are the building blocks for generating movement by the central nervous system (CNS). According to this hypothesis, CNS decreases the complexity of motor control by combination of a small number of muscle synergies. The aim of this work is to investigate similarity of muscle synergies during cycling across various mechanical conditi...
Article
The correct prediction of the optimal motor trajectory is necessary for movement rehabilitation and control systems such as functional electrical stimulation and robotic therapy. It seems that human reaching movements are composed of a set of submovements, each of which is a correction of the overall movement trajectory. Therefore, it is possible t...
Article
Objective: The common criteria for evaluating the performance of the brain-computer interface (BCI) are classification accuracy and information transfer rate (ITR). Due to the fact that the BCI system has direct interaction with patients, the accuracy of estimated ITR is very influential. Although the most popular method for ITR estimation is the W...
Article
Full-text available
Background: The empirical mode decomposition (EMD) is a technique to analyze the steady-state visual evoked potential (SSVEP) which decomposes the signal into its intrinsic mode functions (IMFs). Although for the limited stimulation frequency range, choosing the effective IMF leads to good results, but extending this range will seriously challenge...
Article
Full-text available
Brain-Computer Interface (BCI) is a system that enables users to transmit commands to the computer using their brain activity recorded by electroencephalography. In a Hybrid Brain-Computer Interface (HBCI), a BCI control signal combines with one or more BCI control signals or with Human-Machine Interface (HMI) biosignals to increase classification...
Article
Full-text available
Steady state somatosensory evoked potential (SSSEP) is one of the control signals of brain-computer interfaces (BCI), based on the reflection of skin vibrational stimulation with specific frequencies in brain signals. BCI systems based on SSSEP do not cause visual fatigue in comparison with SSVEP based BCI systems, and they can be used for locked-i...
Article
Full-text available
مقدمه: تشخیص استرس به منظور کنترل، مدیریت و کاهش آن ضروری و مهم است. از طرفی، نظریه‌های متعددی درباره‌ی کمردرد ناشی از استرس وجود دارد. مهم‌ترین نکته در همه‌ی این نظریه‌ها، آن است که عوامل روانی و احساسی باعث نوعی تغییر فیزیولوژیک و در نتیجه، بروز کمردرد می‌شوند. از این رو، به نظر می‌رسد بتوان از سیگنال الکترومایوگرام (Electromyogram یا EMG) عضلات...
Article
Full-text available
Stress is one of the main causes of physical and mental disorders leading to various types of diseases. In recent two decades, stress level detection during driving in order to avoid accidents has attracted much of researchers’ attention. However, existing studies usually neglect the fact that stress level during driving varies due to irregular eve...
Article
Background: Emotion is a psychological process of the mind. It not only has an important role in human interactions, but also has been the subject of attention in human-computer interactions in recent years. Because of diversity and uncertainty nature of the emotion, as well as the individuals’ inability to accurately and quantitatively express the...
Article
Full-text available
Estimating the elbow angle using shoulder data is very important and valuable in Functional Electrical Stimulation (FES) systems which can be useful in assisting C5/C6 SCI patients. Much research has been conducted based on the elbow-shoulder synergies. The aim of this study was the online estimation of elbow flexion/extension angle from the upper...
Article
To increase the number of stimulation frequencies in the Steady-state visual evoked potential (SSVEP)-based brain-computer interface, we are forced to broaden the frequency range due to the frequency resolution restriction. This will enter frequencies with harmonic relation into the stimulation frequency range and lead to increase in frequency reco...
Article
We have developed an open-source graphical user interface (GUI), BCIexplorer, running under multi-platform Matlab environment for assessments of BCI competition data. The data used in this paper is related to BCI competitions recorded while focusing on motor imagery of four classes (left hand, right hand, foot and tongue). BCIexplorer is organized...
Article
Background: For disabled patients who are unable to use their muscles, brain-computer interface (BCI) systems can be used to establish a channel between their brain and outside world. Steady-state visually evoked potentials (SSVEP)-based interfaces are of brain-computer interface-spellers noted in recent years. Methods: In this study, stimulation p...
Article
Full-text available
In this research, classification of the 18 reaching movements was done in 3D space using the elbow flexion/extension angle and the upper arm acceleration. For this, a hierarchical structure was proposed where the approximate region of the movements was determined at high level and then, motion types were recognized exactly at low level. To evaluate...
Conference Paper
Full-text available
One common hypothesis in motor control is that each human movement is created by the combination of a small number of muscle synergies. The muscle synergy analysis is a muscle activation decomposition technique used in electromyogram signals. In this study, simulated muscle activation signals are produced by the combination of wavelets, similar to...
Article
in this study, Recognition of motor imagery EEG is performed using spatial Filters-based feature extraction method. The dataset used, contains data from BCI competition IIIa. EEG signal analysis system consists of three steps: preprocessing, feature extraction and AFNN clustering. In preprocessing, continuous wavelet transform (CWT), the 2D anisotr...
Article
Full-text available
This paper presents a novel approach for driving stress assessment by fuzzy clustering. In previous researches, stress during real-world driving tasks has been detected in discrete levels, but in this study, we demonstrated that considering fixed-levels for stress in long periods is not authentic. Without employing discrete levels of stress, data r...
Conference Paper
FES) ‫ﻣﻌﻤﻮﻝ‬ ‫ﺭﻓﺘﻪ‬ ‫ﺩﺳﺖ‬ ‫ﺍﺯ‬ ‫ﻋﻤﻠﻜﺮﺩﻫﺎﻱ‬ ‫ﺑﺎﺯﻳﺎﺑﻲ‬ ‫ﺑﺮﺍﻱ‬ ‫ﺍﺳﺘﻔﺎﺩﻩ‬ ‫ﻣﻮﺭﺩ‬ ‫ﺳﻴﺴﺘﻢ‬ ‫ﺗﺮﻳﻦ‬ .‫ﺍﺳﺖ‬ ‫ﻧﺨﺎﻋﻲ‬ ‫ﻃﻨﺎﺏ‬ ‫ﺁﺳﻴﺐ‬ ‫ﺍﺯ‬ ‫ﭘﺲ‬ ‫ﺑﺪﻥ‬ ‫ﻱ‬ ‫ﺑﺮﺍﻱ‬ ‫ﺳﻴﺴﺘﻢ‬ ‫ﺍﻳﻦ‬ ‫ﻣﻨﺎﺳﺐ‬ ‫ﻋﻤﻠﻜﺮﺩ‬ ‫ﻣﻲ‬ ‫ﺍﻟﻜﺘﺮﻳﻜﻲ‬ ‫ﺗﺤﺮﻳﻚ‬ ‫ﻛﺎﺭﺁﻣﺪ‬ ‫ﻛﻨﺘﺮﻝ‬ ‫ﺑﻪ‬ ‫ﻧﻴﺎﺯ‬ ‫ﻫﺎ‬ ‫ﺍﻳﻦ‬ ‫ﺑﻪ‬ ‫ﺗﻮﺟﻪ‬ ‫ﺑﺎﺷﺪ.ﺑﺎ‬ ‫ﭘﮋﻭﻫﺶ‬ ‫ﺩﺭ‬ ‫ﻛﻪ‬ ‫ﻛﻨﺘﺮﻝ‬ ‫ﻋﻤﻠﻜﺮﺩ‬ ‫ﺁﺯﻣﺎﻳﺶ‬ ‫ﻭ‬ ‫ﺍﺭﺯﻳﺎﺑﻲ‬ ،‫ﻛﻨﺘﺮﻟﻲ‬ ‫ﻫﺎﻱ‬-‫ﻫﻤﻴﺸﻪ‬ ،‫ﮔ...
Conference Paper
Different pieces of software can be used to simulate virtual movements, such as SIMM-SD/Fast or LifeModAdams. Complexities of using multiple pieces of software and lack of enough knowledge of their concepts to use them professionally has made it inevitable for most researchers to use common and helpful software, MATLAB/SIMULINK. In recent years the...
Conference Paper
Full-text available
— The production of movement in vertebrate species requisites their nervous system to deal with a high degree of freedom. The strategy that the central nervous system (CNS) recruits to overcome this barrier has been a longstanding question among researchers. A hypothesis that sheds light on this motor control problem is that the CNS uses a modular...
Conference Paper
Classification of postures and movements of distal limbs based on surface electromyography (sEMG) of proximal muscles is necessary in myoelectric hand prostheses. With increasing the number of movements, classification problem becomes a serious challenge. In this paper, we have used NINAPRO database that contains sEMG and kinematic data of upper li...
Conference Paper
Full-text available
In all elevators, a circuit that can conduct the elevator to the nearest floor at the earthquake occurrence in order to survive passengers is necessary. In this paper, we have designed and implemented such a circuit in two stages. One recognizes the earthquake and the other guides the elevator to the nearest floor. The degree of earthquake that can...
Conference Paper
This paper presents a fuzzy logic simulation and modeling a controller for an isolated signalized intersection. The idea is used in this system is to minimize the vehicles queue length with minimal waiting time in according to minimize extension of green light time to ensure smooth flow of traffic. A minimum time for the green light has been assume...
Article
Full-text available
Muscle fatigue assessment has been the basis of numerous studies, specifically, in neuromuscular rehabilitation and the applications of FESsystems. Various EMGbased techniques, in time and frequency domains, have been investigatedover years for the detection and evaluationof this phenomenon. The main objective of this study has beento evaluate the...
Article
Full-text available
FES based method used for rehabilitation of patients with spinal cord injury (SCI). One of these methods is FES cycling. FES cycling exercise has to be useful among SCI patients because of creating a periodic activity in the muscles of the lower extremities and stability of seating position. The major challenge for application of FES in rehabilitat...
Conference Paper
Full-text available
Electromyogram (EMG) is used in different applications such as diagnosis and treatment of diseases. Recorded EMG signals from upper trunk muscles are contaminated by electrocardiogram (ECG). Removal of the ECG artifact from surface EMG is not simple because their frequency content is much overlap. In this paper, we compare the results of adaptive N...
Article
In this study, a hybrid PID-like fuzzy logic controller (FLC) is proposed to drive switched reluctance motor (SRM) that consists of a PI fuzzy logic controller and a derivative part. In fact, the output is the sum of a PI fuzzy logic controller and a derivative operator of the error signal. The Mamdani type is used for the fuzzy inference system an...
Conference Paper
Full-text available
Surface electromyograms (EMGs) are valuable in the pathophysiological study and clinical treatment. These recordings are critically often contaminated by cardiac artifact. The purpose of this article was to evaluate the performance of an adaptive filter and artificial neural network (ANN) in removing electrocardiogram (ECG) contamination from surfa...
Article
FES cycling system is introduced as a beneficial rehabilitation method for restoring muscle function in SCI patients. The system is made up of three main parts: a cycling device, a controller and an electrical stimulator. In this paper, a commercial motorized bicycle was augmented with an electrical muscle stimulator and a pedal observation interfa...
Conference Paper
Full-text available
Functional electrical stimulation (FES) is the most commonly used system for restoring functions after spinal cord injury (SCI). In this study, we used a combined feedforward-feedback PID controller for regulating the elbow joint angle. Feedforward controller is unable to make corrections if the actual angle deviates from the desired angle. Feedbac...
Conference Paper
This paper describes the use of a feed-forward neural network for estimating and anticipating elbow joint angle. The method is based on mapping between six different combinations of muscles electromyographic signals (EMG) along with kinematics of the shoulder joint and the flexion/extension angle of elbow joint in four planar movements. Mean square...
Conference Paper
Full-text available
This paper presents a closed-loop control system for regulating blood glucose level in type-1 diabetic patients. The goals of designing controller are 1. avoidance of hypoglycemia (blood glucose concentrations should be above 3mmol/l) and 2. reduction in the blood glucose level (average blood glucose should be less than 7mmol/l) in diabetic patient...
Conference Paper
Full-text available
Functional electrical stimulation (FES) systems restore motor functions after spinal cord injury (SCI). In this study, we used a model consists of a joint, two links with one degree of freedom, and two muscles as flexor and extensor of the joint, which simulated in MATLAB using SimMechanics and Simulink Toolboxes. The muscle model is based on Zajac...
Conference Paper
Full-text available
The main aim in this paper is to use of independent component analysis (ICA) in order to removing electrocardiogram (ECG) from surface electromyogram (EMG) recorded from upper trunk muscles. ICA is a statistical method that is used to decompose independent sources. In this method a collection of contaminated EMG signals recorded from different chan...
Conference Paper
Full-text available
Electromyogram (EMG) is used in different applications such as diagnosis and treatment of diseases. Recorded EMG signals from upper trunk muscles are contaminated by electrocardiogram (ECG). Removal of the ECG artifact from surface EMG is not simple because their frequency content is much overlap. In this paper, we compare the results of adaptive N...
Article
Full-text available
Using FES for reanimation of paralyzed arm has been seriously considered by researchers in recent years. Due to complexities of reaching movement, utilization of a precise model, virtual reality capabilities and advanced control techniques is inevitable. This paper deals with a precise model of paralyzed arm for FES researches. Model elements exact...
Article
Because of the nonlinearity, uncertainty and load disturbances, reanimation of paralyzed limbs involves an accurate and complicated FES control strategy. Investigation of complicated control strategies in turn, involves a precise and comprehensive limb model. In this study, we have created a fairly accurate and comprehensive model of arm in order t...

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