Sharif Digital Repository

Memory and motor deficits are commonly identified in Parkinson's disease (PD). 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is transformed to MPP+ via monoamine oxidase B (MAOB), which causes oxidative stress and destroys dopaminergic (DA) neurons in substantia nigra pars compacta (SNc) and is widely used to create animal models of PD. However, to-date, a comprehensive analysis of the MPTP effects on various aspects of PD does not exist. Here, we provide a systematic review and meta-analysis on the MPTP effects on memory and motor functions by analyzing 51 studies on more than one thousand animals mainly including rats and mice. The results showed that in addition to motor functions... 

Objective: Spine kinematics, kinetics, and trunk muscle activities were evaluated during different stages of a fatigue-induced symmetric lifting task over time. Background: Due to neuromuscular adaptations, postural behaviors of workers during lifting tasks are affected by fatigue. Comprehensive aspects of these adaptations remain to be investigated. Method: Eighteen volunteers repeatedly lifted a box until perceived exhaustion. Body center of mass (CoM), trunk and box kinematics, and feet center of pressure (CoP) were estimated by a motion capture system and force-plate. Electromyographic (EMG) signals of trunk/abdominal muscles were assessed using linear and nonlinear approaches. The L5-S1... 

Variable reluctance resolver (VR-Resolver) is a robust electromagnetic sensor that provides position information for closed-loop control systems of permanent magnet synchronous motors (PMSMs). For specific motion control applications, an outer rotor structure is presented for the VR-Resolver in this article with a nonoverlapping tooth-coil windings configuration to simplify the manufacturing process. The study on the structure of the proposed position sensor is carried out, followed by the description of the working principle. The presented outer rotor VR-Resolver is simulated and its performance is investigated in detail with the aid of transient finite-element analysis (TFEA). Sensitivity... 

Background: Kinematic indices (KIs) are frequently used as objective measures to assess the upper extremities motor performance in post stroke patients. The clinimetric analysis of these indices has been mostly limited to their averaged values over different directions of reaching movements. Recent studies indicate direction dependencies of such motor performances due to neural and/or biomechanical causes. The direction dependencies of such indices and their clinimetric parameters remains to be investigated. Methods: An apparatus was built to perform and measure planar point-to-point reaching tasks in 8 directions using a virtual reality environment. 24 stroke and 18 healthy individuals... 

Background: Impairments of upper limb (UL) sensory-motor functions are common in Parkinson's disease (PD). Virtual reality exercises may improve sensory-motor functions in a safe environment and can be used in tele-rehabilitation. This study aimed to investigate the effects of supervised and non-supervised UL virtual reality exercises (ULVRE) on UL sensory-motor functions in patients with idiopathic PD. Methods: In this clinical trial study, 45 patients with idiopathic PD (29 male) by mean ± SD age of 58.64 ± 8.69 years were randomly allocated to either the control group (conventional rehabilitation exercises), supervised ULVRE or non-supervised ULVRE. Interventions were 24 sessions, 3... 

Aggressive driving has emerged as one of the most studied behaviors in the traffic safety field, due to its association with the odds of motor vehicle crashes and especially fatal crashes. Previous research has investigated the situations which provoke anger while driving, as well as the emotional (anger) and behavioral (aggression) aspects of aggressive driving. However, surprisingly the cognitive aspects of aggressive driving have largely been neglected. This study investigated the psychometric properties of the short-forms of the Driver's Angry Thoughts Questionnaire (DATQ) and the Driving Anger Expression Inventory (DAX) in a sample of professional drivers. Furthermore, the study aimed... 

Since any error in the rotor angle caused by the resolver affects the entire permanent magnet synchronous motor (PMSM) control drive system, it is necessary to investigate its effect on mechanical vibrations. Torsional vibration is accordingly considered in the following study. Thereby, first, the effect of resolver errors on the harmonic content of motor current and, subsequently, torque ripple (TR) was investigated. Then, dynamical modeling is done for the generator-motor-resolver set to get the mechanical frequency response (FR) resulting from the resolver errors. Based on the above modeling, the dynamic equations (DEQs) of the system were derived, and the mechanical characteristics of... 

An autonomous hedge trimmer robot was developed to reduce the harmful effects of traditional hedge trimming method (gasoline-powered hedge trimmer) on operators' bodies and increase the speed and quality of the operation. The robot had five degrees of freedom (PRRRR) structure and was geometrically optimized to simplify the control strategy, enabling it to trim simple, stepped, and circular forms. The control system, consisting of a host computer, servo motors and servo drivers, and controller, guided the robot platform, manipulator, and end-effector as it approached and trimmed the hedge. By using a recognition algorithm and vision-based navigation system, the robot was able to detect the... 

Background: Numerous studies have described the neuroprotective effect of lithium in spinal cord injury in addition to its ameliorative impact on pain sensation. In the present study, we aim to examine the efficacy of 85 mg/kg as well as 50 mg/kg dosage of the lithium chloride (LiCl) through oral consumption in spinal cord injured rats and their effect on gene expression of three candidate genes, corresponding to the hyper-sensitization. Methods: Adult Wistar (male) rats were divided into four experimental groups: control; oral administration of LiCl with 85 mg/kg and 50 mg/kg dosage; and 10 % sucrose receiver as the vehicle. BBB and heat plantar tests were performed weekly throughout four... 

In spite of the extensive literature on the analysis of the muscle synergies during gait, the functionality of these synergies has not been studied in detail. This study explored the relationship between the motor modules and the kinematic maneuvers involved in human walking. Motion and surface electromyography data (of 28 trunk and lower extremity muscles) were acquired from ten healthy subjects during ten trials of self-selected speed gait each. The joint angle trajectories were half-wave rectified and divided into two independent positive directional degrees-of-freedom. The muscle and kinematic synergies were both extracted using the non-negative matrix factorization (NNMF) technique and... 

Freezing of gait (FOG) is a debilitating symptom in patients with Parkinson's disease (PD), which may be associated with motor control impairments in tasks other than gait. This study aimed to examine whether symmetric and asymmetric bimanual coordination is impaired in PD with FOG (PD +FOG) patients and whether dual-task and drug phases may affect bimanual coordination in these patients. Twenty PD +FOG patients, 20 PD patients without FOG (PD –FOG) performed symmetric and asymmetric functional bimanual tasks (reach to and pick up a box and open a drawer to press a pushbutton inside it, respectively) under single-task and dual-task conditions. PD patients were evaluated during on- and... 

In this paper, a novel six-phase outer rotor induction motor equipped with pseudo-concentrated windings is introduced as a robust, reliable, and low-cost solution. Multiple aspects of the proposed motor structure have been investigated such as a design algorithm and an analytical modeling based on the modified winding function considering the skew effect. The effect of using variable number of turns for the coils has been examined on the pseudo-concentrated windings. An appropriate optimization problem has been also defined to maximize the power factor and efficiency and to minimize the output torque ripple. The designed motor has been fabricated to verify the accuracy of the design... 

High-efficiency Permanent Magnet Synchronous Motors (PMSMs) are widely used in industry. Subsequently, resolvers' employment is increasing in the drive of PMSMs. Measuring the rotor angle using a resolver needs a costly Resolver to Digital Converter (RDC). Therefore, a low-cost analog RDC is designed against the conventional Angle Tracking Observers (ATOs) in the following study. The designed RDC has satisfactory accuracy, simplicity, and enduring against excitation frequency. Firstly, an overview of the resolver is shown, and subsequently, the circuit of the designed RC is described thoroughly. Ultimately, the simulations' outcomes are displayed, and comparing our design with others... 

Driving behavior monitoring by smartphone sensors is one of the most investigated approaches to ameliorate road safety. Various methods are adopted in the literature; however, to the best of our knowledge, their robustness to the prediction of new unseen data from different drivers and road conditions is not explored. In this paper, a two-phase Machine Learning (ML) method with taking advantage of high-pass, low-pass, and wavelet filters is developed to detect driving brakes and turns. In the first phase, accelerometer and gyroscope filtered time series are fed into Random Forest and Artificial Neural Network classifiers, and the suspicious intervals are extracted by a high recall. Following... 

High-efficiency Permanent Magnet Synchronous Motors (PMSMs) are widely used in industrial applications. Subsequently, resolvers as position sensors experience increasing usage in the drive of PMSMs. Measuring the rotor's position using a resolver needs a costly Resolver to Digital Converter (RDC). Therefore, in this paper, a software-based, low-cost RDC is presented against the conventional Angle Tracking Observers (ATOs). The proposed RDC is a high-Accuracy two-stage Deep Neural Network (DNN)-based one. In this regard, an overview of the resolvers' function and the general methodology to DNN training is given. Then, the case study is done on the gathered data from the set of the resolver... 

Objectives: This study aimed to investigate the effect of upper extremity coordination exercises based on fatigue prediction on fine and gross manual dexterity, upper limb motor function, shoulder and elbow proprioception, occupational performance, and activities of daily living in chronic stroke survivors. Methods: In this pilot double-blind randomized clinical trial, 24 chronic strokes were enrolled using the non-probability sampling method. Participants were randomly allocated to the control (received routine occupational therapy) and intervention (received upper extremity coordination exercises based on fatigue prediction using the Kinect) groups. Before and after the interventions (six... 

Fine particulate matter cause profound adverse health effects in Iran. Road traffic is one of the main sources of particulate matter (PM) in urban areas, and has a large contribution in PM2.5 and organic carbon concentration, in Tehran, Iran. The composition of fine PM vehicle emission is poorly known, so this paper aims to determine the mixed fleet source profile by using the analysed data from the two internal stations and the emission factor for PM light-duty vehicles emission. Tunnels are ideal media for extraction vehicle source profile and emission factor, due to vehicles are the only source of pollutant in the urban tunnels. In this study, PM samples were collected simultaneously in... 

Background: Cerebral palsy (CP) is a non-progressive encephalopathy before, dur-ing, or after childbirth with almost the most common type, i.e. spastic diplegic, leading to a frequent walking problem, In-toeing. Orthoses can reduce the consequences of CP. Objective: This study aimed to evaluate the effect of combining twister wrap orthoses (TWO) with high-top shoes on the balance parameters of children with spastic diplegic CP. Material and Methods: In this quasi-experimental study, twenty children (aged 6.8 ± 0.5 years) with spastic diplegic CP with in-toeing gait participated. The tests were conducted in three conditions: 1) in bare-foot, 2) with high-top shoes, and 3) with high-top shoes... 

In this study, we introduce a novel three-dimensional micro-scale robot capable of swimming in low Reynolds number. The proposed robot consists of three rotating disks linked via three perpendicular adjustable rods, actuated by three rotary and three linear motors, respectively. The robot mechanism has an important property which makes it superior to the previously designed micro swimmers. In fact, our goal is designing a micro swimmer which its controllability matrix has full rank and hence it will be capable to perform any desired maneuver in space. After introducing the mechanism and derivation of the dynamical equations of motion, we propose a control method to steer the robot to the... 

Objective: Spine kinematics, kinetics, and trunk muscle activities were evaluated during different stages of a fatigue-induced symmetric lifting task over time. Background: Due to neuromuscular adaptations, postural behaviors of workers during lifting tasks are affected by fatigue. Comprehensive aspects of these adaptations remain to be investigated. Method: Eighteen volunteers repeatedly lifted a box until perceived exhaustion. Body center of mass (CoM), trunk and box kinematics, and feet center of pressure (CoP) were estimated by a motion capture system and force-plate. Electromyographic (EMG) signals of trunk/abdominal muscles were assessed using linear and nonlinear approaches. The L5-S1...