Motor Control Parameters Research Articles

Acute stress does not influence the learning of a precise manual task: A randomized clinical trial

Acute stress is frequent in sports and rehabilitation contexts and can impact cognitive processes essential for motor learning. This study aimed to investigate the influence of induced acute stress on the learning of a precise manual task, examining its effect on five key parameters of fine motor control: trajectory error, trajectory error direction, time error, tracing accuracy, and task accuracy. A double-masked, randomized clinical trial with 62 participants (average age 20.65 ± 2.54 years; 39 females; 23 males) was conducted. To examine the effects of stress, participants were assigned to either a stress or a control group through stratified randomization by sex. Initially, all participants underwent the Maastricht Acute Stress Test (in its acute stress and control versions, respectively). Subsequently, they performed the precise manual task on a graphic tablet at three stages of the learning process: acquisition, short-term retrieval, and long-term retrieval. Electrodermal activity and heart rate variability were recorded to assess stress induction. Data analysis from 30 stress group participants and 25 control group participants revealed no statistically significant differences between groups in any of the variables studied at the three learning stages. Both groups exhibited statistically significant improvements in time error, trajectory error direction, and tracing accuracy during both short-term and long-term retrieval compared to acquisition. Our findings suggest that acute physical and psychological stress does not markedly impair learning a precise manual task of adhering to a specific trajectory and pace among young adults.

Decoding kinematic information from beta-band motor rhythms of speech motor cortex: a methodological/analytic approach using concurrent speech movement tracking and magnetoencephalography.

Articulography and functional neuroimaging are two major tools for studying the neurobiology of speech production. Until now, however, it has generally not been feasible to use both in the same experimental setup because of technical incompatibilities between the two methodologies. Here we describe results from a novel articulography system dubbed Magneto-articulography for the Assessment of Speech Kinematics (MASK), which is technically compatible with magnetoencephalography (MEG) brain scanning systems. In the present paper we describe our methodological and analytic approach for extracting brain motor activities related to key kinematic and coordination event parameters derived from time-registered MASK tracking measurements. Data were collected from 10 healthy adults with tracking coils on the tongue, lips, and jaw. Analyses targeted the gestural landmarks of reiterated utterances/ipa/ and /api/, produced at normal and faster rates. The results show that (1) Speech sensorimotor cortex can be reliably located in peri-rolandic regions of the left hemisphere; (2) mu (8-12 Hz) and beta band (13-30 Hz) neuromotor oscillations are present in the speech signals and contain information structures that are independent of those present in higher-frequency bands; and (3) hypotheses concerning the information content of speech motor rhythms can be systematically evaluated with multivariate pattern analytic techniques. These results show that MASK provides the capability, for deriving subject-specific articulatory parameters, based on well-established and robust motor control parameters, in the same experimental setup as the MEG brain recordings and in temporal and spatial co-register with the brain data. The analytic approach described here provides new capabilities for testing hypotheses concerning the types of kinematic information that are encoded and processed within specific components of the speech neuromotor system.

Low order speed harmonic suppression in FOC-PMSM based on the closed-loop transfer mechanism of injected voltage

In the field oriented control (FOC) permanent magnet synchronous motor (PMSM) servo system, torque ripple impairs motor performance. Harmonic injection methods can suppress torque ripple by injecting additional voltage harmonic to offset the existing speed harmonic. However, since FOC is a closed-loop motion control strategy, the transfer path from injected voltage harmonic to speed harmonic is affected by FOC, especially in very low frequency. Due to the influence of FOC on the transfer function, the relation between the injected voltage harmonic and speed harmonic varies with operating conditions and motor control parameters. It causes the existing harmonic injection methods ineffective to suppress low order speed harmonics. To solve the problem, in this paper, the closed-loop transfer mechanism of injected voltage harmonics is analyzed and the closed-loop transfer function is derived. Based on the derived closed-loop transfer function, a low order speed harmonic suppression method is proposed. With the derived transfer function, the proposed method can adapt to the variations of the relation between low order injected voltage harmonic and speed harmonic under different operation conditions. Finally, the accuracy of the derived closed-loop transfer function and the effectiveness of the proposed low order speed harmonic suppression method are evaluated by experiment.

Azure Kinect performance evaluation for human motion and upper limb biomechanical analysis

Human motion tracking is a valuable task for many medical applications. Marker-based optoelectronic systems are considered the gold standard in human motion tracking. However, their use is not always feasible in clinics and industrial environments. On the other hand, marker-less sensors became valuable tools, as they are inexpensive, noninvasive and easy to use. However, their accuracy can depend on many factors including sensor positioning, light conditions and body occlusions. In this study, following previous works on the feasibility of marker-less systems for human motion monitoring, we investigate the performance of the Microsoft Azure Kinect sensor in computing kinematic and dynamic measurements of static postures and dynamic movements. According to our knowledge, it is the first time that this sensor is compared with a Vicon marker-based system to assess the best camera positioning while observing the upper body part movements of people performing several tasks. Twenty-five healthy volunteers were monitored to evaluate the effects of the several testing conditions, including the Azure Kinect positions, the light conditions, and lower limbs occlusions, on the tracking accuracy of kinematic, dynamic, and motor control parameters. From the statistical analysis of the performed measurements, the camera in the frontal position was the most reliable, the lighting conditions had almost no effects on the tracking accuracy, while the lower limbs occlusion worsened the accuracy of the upper limbs. The assessment of human static postures and dynamic movements based on experimental data proves the feasibility of applying the Azure Kinect to the biomechanical monitoring of human motion in several fields.

Improvement of Braking Response Performance of Fault-Tolerant Dual Winding Motor for Integrated Brake System Using Winding Switching

Unlike the winding structure of existing three-phase single winding motors, the winding structure of the dual winding motor (DWM) contains a master part and two slave parts. Thus, when the master part fails, it can be driven using the remaining slave part. It is applicable to various electric parts driving the integrated electric brake (IEB) system; thereby securing the high reliability of vehicle parts. However, in the existing DWM, there is an overheating problem owing to the increase in current because it operates with half the motor during the faulty mode. Therefore, a compensation method for the increase in current in a faulty mode was employed by increasing the stacking length of the DWM. However, although it solves the overheating problem of the DWM in the faulty mode, the motor output performance and braking performance of the IEB system are degraded in the normal mode because of the change in the motor control parameters. Thus, in this paper, we propose a DWM with winding switching (WS) to simultaneously solve the DWM overheating problem in the faulty mode and the DWM’s performance degradation problem in the normal mode. The output performance of the DWM with an increased stack length and the previously developed base model are compared to verify the performance of the proposed DWM with WS. As a result of the comparison, unlike the DWM with an increased stack length, in which the maximum speed is reduced by 20.5% compared to the existing base model during quick braking in the normal mode, the proposed DWM with WS has no performance degradation. In other words, it is confirmed that the proposed DWM with WS effectively solves the overheating problem during faulty mode, while simultaneously solving the performance degradation problem of the IEB system during the normal mode.

Research on gear crack fault diagnosis model based on permanent magnet motor current signal

To solve the problem that it is inconvenient to install additional sensors to detect fault signals on the gear of the shearer, the permanent magnet motor control model was first established, and the motor control parameters were determined. Then, the gear mesh stiffness is used as the main judgment basis for gear failure. The gear failure model and the system torsion dynamics model are established. The gear meshing stiffness curve under the crack fault is fitted. Finally, the transmission system overall dynamic model is proposed to obtain the motor current and gear fault information. The influence of different faults on the system electromechanical performance is studied. The mapping relationship between the crack fault and the current is established. The typical characteristics under fault conditions are extracted, which is an important reference for studying the health status of the cutting drive system in the shearer.

Speech Kinematics and Coordination Measured With an MEG-Compatible Speech Tracking System.

Articulography and functional neuroimaging are two major tools for studying the neurobiology of speech production. Until recently, however, it has generally not been possible to use both in the same experimental setup because of technical incompatibilities between the two methodologies. Here we describe results from a novel articulography system dubbed Magneto-articulography for the Assessment of Speech Kinematics (MASK), which we used to derive kinematic profiles of oro-facial movements during speech. MASK was used to characterize speech kinematics in two healthy adults, and the results were compared to measurements from a separate participant with a conventional Electromagnetic Articulography (EMA) system. Analyses targeted the gestural landmarks of reiterated utterances /ipa/, /api/ and /pataka/. The results demonstrate that MASK reliably characterizes key kinematic and movement coordination parameters of speech motor control. Since these parameters are intrinsically registered in time with concurrent magnetoencephalographic (MEG) measurements of neuromotor brain activity, this methodology paves the way for innovative cross-disciplinary studies of the neuromotor control of human speech production, speech development, and speech motor disorders.

Design and Analysis of a Low-Cost Electronically Controlled Mobile Ventilator, Incorporating Mechanized AMBU Bag, for Patients during COVID-19 Pandemic.

The outbreak of novel COVID-19 has severely and unprecedentedly affected millions of people across the globe. The painful respiratory distress caused during this disease calls for external assistance to the victims in the form of ventilation. The most common types of artificial ventilating units available at the healthcare facilities and hospitals are exorbitantly expensive to manufacture, and their number is fairly inadequate even in the so-called developed countries to cater to the burning needs of an ever-increasing number of ailing human subjects. According to available reports, without the provision of ventilation, the novel COVID-19 patients are succumbing to their ailments in a huge number of cases. This colossal problem of the availability of ventilator units can be addressed to a great extent by readily producible and cost-effective ventilating units that can be used on those suffering patients during an acute emergency and in the absence of conventional expensive ventilators at hospitals and medical care units. This paper has made an attempt to design and simulate a simple, yet effective, mechanized ventilator unit, which can be conveniently assembled without a profuse skillset and operated to resuscitate an ailing human patient. The stepper motor-controlled kinematic linkage is designed to deliver the patient with a necessitated discharge of air at optimum oxygen saturation through the AMBU bag connected in a ventilation circuit. With the associated code on MATLAB, the motor control parameters such as angular displacement and speed are deduced according to the input patient conditions (age group, tidal volume, breathing rate, etc.) and thereafter fed to the controller that drives the stepper motor. With a proposed feedback loop, the real-time static and dynamic compliance, airway resistance values can be approximately determined from the pressure variation cycle and fed to the controller unit to adjust the tidal volume as and when necessary. The simplistic yet robust design not only renders easy manufacturability by conventional and rapid prototyping techniques like 3D printing at different scales but also makes the product easily portable with minimal handling difficulty. Keeping the motto of Health for All as envisioned by the WHO, this low-cost indigenously engineered ventilator will definitely help the poor and afflicted towards their right to health and will help the medical professionals buy some time to manage the patient with acute respiratory distress syndrome (ARDS) towards recovery. Moreover, this instrument mostly includes readily available functional units having standard specifications and can be considered as standard bought-out items.

Optimal Design of an Inverter-Fed PMSM for a Brake System Considering Variation in Motor Control Parameters and Input Voltage

This study proposes an optimal design approach for an inverter-fed permanent magnet synchronous motor (PMSM) considering the variation in motor control parameters and input voltage (inverter output voltage), which vary with respect to the temperature and loading conditions, in an integrated brake system. In an integrated brake system, a quick response to load changes is crucial. Therefore, in this study, to consider the fluctuation in control variables and input voltage, the motor control parameters and input voltage were first calculated according to the operating temperature and loading condition. Subsequently, based on the calculated conditions and the approximated motor input voltage and control parameters, the objective functions corresponding to motor characteristics in transient and steady states were formulated using design-of-experiment (DOE), the moving least square method (MLSM), and the finite element method (FEM). Finally, the optimal design was performed using the genetic algorithm (GA). The validity of the proposed optimal design approach was verified by comparing its optimization results with the FEM analysis results. Thus, it was confirmed that a motor can be designed for an integrated brake system by considering the motor control parameters and motor input voltage, which vary with the driving conditions.

Fear-avoidance beliefs, anxiety and depression are associated with motor control and dynamics parameters in patients with chronic low back pain

PurposeTo evaluate the influence of fear-avoidance beliefs, anxiety and depression on dynamic and motor control parameters before and after Functional Restoration Program. MethodsPatients were divided into three groups depending on clinical scores scores. Dynamic and motor control parameters were extracted from gait analysis. ResultsPatients showed different ways based on preferred walking speed, capacity benefit, peaks of propulsion and gait stability in function of clinical scores. ConclusionFear-avoidance beliefs associated to anxiety and depression influence biomechanics on overground walking. We depicted different ways to adapt their gait in function of biopsychosocial scores. Functional Restoration Program influence these ways.

Portable System for Home Use Enables Closed-Loop, Continuous Control of Multi-Degree-of-Freedom Bionic Arm.

Commercial prosthetic hands are frequently abandoned due to unintuitive control methods and a lack of sensory feedback from the prosthesis. Advanced neuromyoelectric prostheses can restore intuitive control and sensory feedback to prosthesis users and potentially reduce abandonment. However, not all advanced prosthetic systems are deployable for home use on portable systems with limited computational power. In this work, we use a commercially available portable neural interface processor (the Ripple Neuro Nomad), and a multi-degree-of-freedom bionic arm (the DEKA LUKE Arm) to create a closed-loop neuromyoelectric prosthesis. The system restores intuitive, independent, continuous control over the arm's six-degrees-of-freedom and provides sensory feedback for up to 288 neural and six vibrotactile channels. Additionally, the large storage capacity of the system enables high-resolution logging of EMG, hand positions, prosthesis sensors, and stimulation parameters. We developed two GUIs enabling wireless, real-time adjustments to motor control and feedback parameters: one with nearly full control over motor control and feedback parameters for investigators, and one with restricted capabilities enabling end-user safety. We verified the system's closed-loop function through a fragile egg task with vibrotactile sensory feedback. We tested the neural stimulation with an amplifier capable of eliciting transcutaneous percepts. This neuromyoelectric prosthetic system will be used for an extended take-home trial that could provide strong clinical justification for advanced, closed-loop prostheses.Clinical Relevance- This work establishes an advanced, intuitive, sensorized prosthesis that can be used in home and clinical settings.

Imposing demands on precision influences the hands differently during alternated discrete touching

PurposeHow demands of precision influence the performance during alternated discrete touching is not well established in the literature. Hence, we compared both hands performance during alternated touching, manipulating the precision demand.MethodsOverall, 23 right-handed adults participated in this study. The first task consisted of alternated touching with a pencil on both sides of a blank paper, performing as fast as possible, considering the first touch as reference for the next ones. Subsequently, touch dispersion and width were measured, and circular targets were drawn with those proportions. The second task consisted of performing as many hits as possible inside those targets. Apart from the delimitated target, increasing precision demand, the task parameters were equal.ResultsMovement time increased and the number of touches decreased from the first to the second task. However, the preferred hand displayed greater reductions in performance.ConclusionsThe perceptual constraint of adding a visual target affects motor control parameters in alternated touching, causing decrements in performance in both hands, but more evidently in the preferred right hand.

Sizing parameters of interior permanent magnet synchronous motor based on torque-speed characteristics

This paper presents a sizing algorithm for an interior permanent magnet synchronous motor based on its torque-speed characteristic and how these characteristic shifts because of changing motor’s parameters. This knowledge must be helpful in designing motor control systems, where there is no need for a precise model. Also, the proposed method is useful for rapid prototyping based on the existing motor model. The methodology for calculating the torque-speed characteristics is given. The resulting calculated graphs are given. PMSM motor control parameters are designed based on the reference model and verified in MATLAB/Simulink software package. Simulation results are given.

Body adaptation to Dance: A Gerontological Perspective.

A number of studies have investigated the effectiveness of dance in older adults in the context of healthy aging. Analysing results across studies is important to understand whether dance in older adults is an effective adjunctive intervention for the healthy aging. To summarize the current research results about the effectiveness of dance in older adults in the context of healthy aging, and to identify key areas for future research. The search was conducted in Web of Science, PubMed and Google Scholar databases, using the following search string and Boolean logic (‘AND’, ‘OR’) locating studies published between database inception and September 2018: Dance OR contemporary dance OR ballroom dance OR Latin dance OR standard dance OR hip-hop dance OR tango AND Cardiovascular OR circulation AND Emotion OR well-being OR blood pressure OR disease OR thrombosis OR vascular OR glucose OR blood OR cardiac OR mental OR heart rate. Two reviewers independently extracted studies data. Eight suitable publications were included. The results showed that dance promote improvements in cognitive parameters when compared to other types of exercise or no-exercise. Significant effects were found on some physiological parameters, even after a short intervention period. Dance proved to be able to assist older adults in the context of healthy aging. The improvements in the cognitive, physiological and motor control parameters are very relevant for this population, due to the impact in a better quality of life.

Особенности моторного контроля здоровых добровольцев в пассивном экзоскелете нижних конечностей

Introduction. In an observation on 24 healthy young male volunteers, the effect of the passive exoskeleton of the lower extremities on motor control was studied. In the exoskeleton, a was studied, which is an intermediate state between standing and sitting - a hybrid Methods. We analyzed the data of surface electromyography from Musculus quadriceps femoris and Musculus tibialis anterior of both legs, data from the force platform, and parameters of instruction execution in a task with visual feedback on the support reaction during alternate manipulation with both hands. One of the conditions influencing the parameters of motor control in the hybrid posture is the predominant type of sensory organization in the usual vertical posture. Results Differences between the “hybrid posture” under the described conditions from a simple vertical were more clearly revealed during rhythmic purposeful swinging of the sample volunteers in the sagittal and frontal planes, as a redistribution of the activity of the muscles under study and differences in the swinging amplitude in the frontal plane for conventional “proprioceptors” and “visuals”. Discussion. The control of the upper limbs (pressure on the fixed handle due to the instruction) practically did not depend on the peculiarities of the sensory organization of the under the conditions of the given visual control. In the variants of the vertical with and without exoskeleton, there was a difference in the complexity of manipulation (more in the hybrid posture) with the same effectiveness.

Increases in scattered light causes increased darkness

Inkjet printer motor control consists of moving the printhead in the scan direction and in the process direction. Both movements have different objectives. Scan direction movement needs to have constant velocity and process direction movement needs to have accurate movement. In this paper, we discuss a method for controlling the velocity of the printhead and how to tune the motor control parameters. We also design six test pages for testing accuracy of the printhead movement and cartridge properties. For each test page, we discuss expected prints, common printer control problems that could alter the print quality, and how to identify them.

Understanding the Consequences of Repetitive Subconcussive Head Impacts in Sport: Brain Changes and Dampened Motor Control Are Seen After Boxing Practice.

ObjectivesThe potential effects of exposure to repetitive subconcussive head impacts through routine participation in sport are not understood. To investigate the effects of repetitive subconcussive head impacts we studied boxers following customary training (sparring) using transcranial magnetic stimulation (TMS), decomposition electromyographic (EMG) and tests of memory.MethodsTwenty amateur boxers performed three 3-min sparring bouts. Parameters of brain function and motor control were assessed prior to sparring and again immediately, 1 h and 24 h post-sparring. Twenty control participants were assessed following mock-sparring.ResultsOne hour after sparring boxers showed increased corticomotor inhibition, altered motor unit recruitment strategies, and decreased memory performance relative to controls, with values returning to baseline by the 24 h follow up.ConclusionRepetitive subconcussive head impacts associated with sparring resulted in acute and transient brain changes similar to those previously reported in soccer heading, providing convergent evidence that sport-related head impacts produce a GABAergic response. These acute changes in brain health are reminiscent of effects seen following brain injury, and suggest a potential mechanism underlying the damaging long-term effects of routine repetitive head impacts in sport.

Neuromusculoskeletal model that walks and runs across a speed range with a few motor control parameter changes based on the muscle synergy hypothesis

Humans walk and run, as well as change their gait speed, through the control of their complicated and redundant musculoskeletal system. These gaits exhibit different locomotor behaviors, such as a double-stance phase in walking and flight phase in running. The complex and redundant nature of the musculoskeletal system and the wide variation in locomotion characteristics lead us to imagine that the motor control strategies for these gaits, which remain unclear, are extremely complex and differ from one another. It has been previously proposed that muscle activations may be generated by linearly combining a small set of basic pulses produced by central pattern generators (muscle synergy hypothesis). This control scheme is simple and thought to be shared between walking and running at different speeds. Demonstrating that this control scheme can generate walking and running and change the speed is critical, as bipedal locomotion is dynamically challenging. Here, we provide such a demonstration by using a motor control model with 69 parameters developed based on the muscle synergy hypothesis. Specifically, we show that it produces both walking and running of a human musculoskeletal model by changing only seven key motor control parameters. Furthermore, we show that the model can walk and run at different speeds by changing only the same seven parameters based on the desired speed. These findings will improve our understanding of human motor control in locomotion and provide guiding principles for the control design of wearable exoskeletons and prostheses.

Chronic Non-specific Low Back Pain and Motor Control During Gait.

Background: Chronic non-specific low back pain (LBP) poses a major socioeconomic problem, although the mechanisms are not yet clear. Impaired motor control is one of the mechanisms being discussed.Objectives: The purpose of this review is to provide an overview of motor control parameter differences between individuals with and without non-specific LBP during gait.Methods: A literature search on Medline, SportDiscus, PsychInfo, PsychArticels, EMBASE, and Scopus was performed. Twenty-nine articles comparing healthy adults and adults with chronic non-specific LBP in neuromuscular and/or biomechanical parameters during walking or running were examined. Data extraction and quality assessment were independently performed by two persons. Among others, we extracted population, conditions, outcome measures, and results.Results: The results showed that persons with and without non-specific LBP differed in several parameters of motor control, which was indicated by a lower movement amplitude of the pelvis, more in-phase coordination, lower ground reaction forces, higher stride-to-stride variability and a higher activity in ES in the LBP group.Conclusion: Despite no strong evidence for any of the parameters, a combination of biomechanical and neuromuscular parameters provides a conclusive explanation. Impaired motor control during walking is reflected in higher activity of the erector spinae, which leads to a stiffened lumbar-pelvic region. Different acquisition and processing of data renders making comparisons difficult, whereby standards for future research are necessary.

A REVIEW ON UNMANNED WATER SURFACE VEHICLE

Unmanned Surface Vehicle is the dimension of robotics and wireless sensor network on the water surface. Many countries are continuously developing USVs for the defense and research purposes in water bodies. This paper addresses the year wise study of some popular USVs. As the computer developed with respect to its generation, the efficiency of the USVs also got enhanced. Broadly water is categorized into two categories as salt water and fresh water. Both water bodies are different in their properties like size, salinity, pH level and ecology. In the same way, the vehicle’s design, sensors for navigation, motor control, and others parameters get changed. The USA played an important role in developing unmanned Surface vehicles. This paper briefs about the gradual improvisation in the field of USV with respect to development in the computers and its generations. It is an interesting fact that the application domain of USVs is shifted from war zone to human's afflux.