Ballistic Movements Research Articles

Dystonia as a prominent presenting feature in developmental and epileptic encephalopathies: A case series

IntroductionAlthough there has been increasing recognition of the occurrence of non-epileptic involuntary movements in developmental and epileptic encephalopathies (DEEs), the spectrum of dystonic presentations associated with these conditions remains poorly described. We sought to expand the catalogue of dystonia-predominant phenotypes in monogenic DEEs, building on the recently introduced concept of an epilepsy-movement disorder spectrum. MethodsCases were identified from a whole-exome-sequenced cohort of 45 pediatric index patients with complex dystonia (67% sequenced as parent-child trios). Review of molecular findings in DEE-associated genes was performed. For five individuals with identified DEE-causing variants, detailed information about presenting phenotypic features and the natural history of disease was obtained. ResultsDe-novo pathogenic and likely pathogenic missense variants in GABRA1, GABBR2, GNAO1, and FOXG1 gave rise to infantile-onset persistent and paroxysmal dystonic manifestations, beginning in the limb or truncal musculature and progressing gradually to a generalized state. Coexisting, less prominent movement-disorder symptoms were observed and included myoclonic, ballistic, and stereotypic abnormal movements as well as choreoathetosis. Dystonia dominated over epileptic neurodevelopmental comorbidities in all four subjects and represented the primary indication for molecular genetic analysis. We also report the unusual case of an adult female patient with dystonia, tremor, and mild learning disability who was found to harbor a pathogenic frameshift variant in MECP2. ConclusionsDystonia can be a leading clinical manifestation in different DEEs. A monogenic basis of disease should be considered on the association of dystonia and developmental delay-epilepsy presentations, justifying a molecular screening for variants in DEE-associated genes.

Mathematical Modelling of the Fruit-Stone Culture Seeds Calibration Process Using Flat Sieves

Abstract The paper provided describes a mathematical model of calibration process of fruit-stone culture seeds of cherry, sweet cherry, cherry-plum, apricot and almond using flat sieves with impact shock ball cleaners oscillating in the horizontal plane. It has been defined that the mathematical expectation of time of knocking out the fruit-stone from the sieve opening T ⌢ \mathord{\buildrel{\lower3pt\hbox{$\scriptscriptstyle\frown$}}\over T} is the minimum value of ratio of average time of complete ball motion cycle in space under sieve to the probability of knocking out the stone by a ball with the kinetic energy level of 2 Mj. The dependences of energy distribution density of ball on impact on the sieve have been obtained, based on which the intervals of ball cleaner parameters have been determined, i.e. the ball diameter D belongs to the interval 25–35 mm; the space height H under sorting sieve belongs to the interval 1.2D–1.4D mm; the value range for distance between rods t belongs to the interval 0.5D–0.7D mm. Using the method of golden section, the following parameters of ball cleaner were obtained: D = 33 mm, t = 23 mm, H = 40 mm. The parameters obtained provide mathematical expectation of time of knocking out the fruit-stone from the sieve opening T ⌢ \mathord{\buildrel{\lower3pt\hbox{$\scriptscriptstyle\frown$}}\over T} = 0.03 s. Consequently, the average ball velocity v ⌢ \mathord{\buildrel{\lower3pt\hbox{$\scriptscriptstyle\frown$}}\over v} is = 0.4 m∙s-1, and the average ball path is L ⌢ \mathord{\buildrel{\lower3pt\hbox{$\scriptscriptstyle\frown$}}\over L} = 0.006 m.

ANALYSIS OF RIGID AND FLEXIBLE DYNAMICS OF A SPACE-SLIDER-CRANK MECHANISM BASED ON FINITE ELEMENT METHOD

The investigation analyzes effects of clearance size in revolute and spherical joints with clearance on rigid-flexible dynamic of a space slider crank mechanism by finite element method. The model of the mechanism was designed by Solidworks and then velocity, acceleration, displacement, stress and contact force were determined by finite element analysis of rigid-transient dynamic in ANSYS. The results simulation indicated that the clearance size in revolute and spherical with clearance has sightly effected on the velocity of the slider, but has significantly effected on acceleration, contact force as journal and ball impact into bearing and socket with high peaks of acceleration and contact force as presented in the graph of acceleration and contact forces. The graph outlined that journal and ball motion with three types: free light, contact and impact motion. Clearance size created deviation for the displacement of the slider from 4.29 mm to 9.87 mm and maximum principal stress increases from 8.4 MPa to 10 MPa when clearance size increases from 0 mm to 0.3 mm.

Immediate Effects of Arm Reaching Training in Standing on Postural Control Differ between Right and Left Stroke Individuals

BackgroundArm reaching training in standing for several weeks affects the postural control of individuals recovering from cerebrovascular accident (CVA). Whether these effects differ with the side of the brain lesion are unknown. ObjectivesTo examine the immediate effects of a training session of arm reaching movements on the balance and trunk motion of individuals who suffered a right or left CVA. Materials and methodsThirty-six adults divided into four groups (i.e., right CVA, left CVA, right control, and left control) performed 120 reaches in a standing position toward one of three target heights. Before and after the reaching trials, participants stood as quiet as possible on two force plates and had their postural sway, trunk motion, and body weight distribution assessed. ResultsCVA groups showed greater postural sway regardless of the brain lesion's side compared to the control groups. After the session of reaching movements, the left stroke group reduced the postural sway and trunk displacements. Larger ranges of weight-bearing asymmetry were more frequent after the training session, mainly for the right stroke group. ConclusionsA single session training of reaching movements affects mostly the postural control of left stroke survivors. More training sessions may be needed for individuals after right stroke to show balance improvements. The current findings support the hemispheric specialization for postural control and suggest that the training involving arm movements in standing can benefit the motor rehabilitation of stroke individuals.

Movement disorders O-MD001. The role of neurophysiological testing for differential diagnosis of functional tremor in busy clinic

Introduction . The presenting phenomenology of functional tremor (FT) is complex making clinical diagnosis challenging. However, certain features from neurophysiological testing may aid the differential diagnosis of FT. Aim of investigation: To study the clinical characteristics and neurophysiological findings of FT and compare with organic tremor (OrgT). Methods . 12 patients with suspected FT were recruited. Clinical characteristics and neurophysiological features were reviewed and compared with OrgT. Results . Of the 12 patients, 50% were neurophysiologically confirmed as having FT. There were no differences in age of onset, disease duration or psychiatric comorbidity between FT and OrgT, but FT is more common in female than OrgT (M:F: 5:1 vs 2:4, p = 0.24). Stressful events were commonly reported as a precipitating factor in FT. Presenting symptoms of FT were mostly unilateral (83%) and task-specific (67%) with a possible dystonic posture. The aetiologies of OrgT mimicking FT were enhanced physiological tremor (4 patients), PD (1 patient) and orthostatic tremor (1 patient). Clinical signs and neurophysiological features that can significantly differentiate between FT and OrgT were distractibility (83% vs 7%, p = 0.02), entrainment (67% vs 0%, p = 0.01), distractibility/frequency shift with tapping (100% vs 0%, p < 0.01), pause of tremor during ballistic movement (67% vs 0%, p = 0.01), coactivation at tremor onset (67% vs 0%, p = 0.01) and inconsistency of tremor (60% vs 0%, p = 0.03) respectively. Conclusion . Our study demonstrates the role of neurophysiological testing in those with suspected FT. In particular, distractibility appears to be an important clinical sign for diagnosis of FT.

P-MD004. Peak dose ballistic movements towards the implantable pulse generator life end in deep brain stimulation

Introduction . The objective of this case report is to highlight the unusual presentation of peak dose ballistic movements towards the end of the implantable pulse generator (IPG) life span in a patient with bilateral sub-thalamic nucleus (STN) deep brain stimulation (DBS). Results . We report a case of sudden severe peak dose ballistic movements and increased “off” periods in a PD patient with bilateral STN DBS towards the end life of the IPG despite a normal battery range according to the Medtronic Battery Status Indicator. The Unified Parkinson Disease Rating Scale III (UPDRS III) escalated by 12 points (from 63 to 75 points) with severe uncontrollable peak dose dyskinesia despite no medication adjustment. Stimulation settings were cut down to as low as 1.0 V on the left STN, and 1.5 V on the right STN at a frequency of 130 Hz and pulse width of 60 μs, yet the ballistic movements were still noticeable. The patient remained in “on” period with no dyskinesia throughout the day after replacement of the IPG with similar stimulation settings prior to the replacement of the IPG, with 2.1 V on the left STN, and 1.6 V on the right STN at a frequency of 130 Hz and pulse width of 60 μs. The patient’s UPDRS-III score was at 62 points after the replacement of IPG. Conclusion . We observed that the battery status indicator did not accurately predict the battery life of the IPG. Peak dose ballistic movements towards the end life of the IPG is an unusual presentation and could be an indicator of end life of the IPG in DBS.

Bilateral Squatting Mechanics Are Associated With Landing Mechanics in Anterior Cruciate Ligament Reconstruction Patients

Background: Proper lower extremity biomechanics during bilateral landing is important for reducing injury risk in athletes returning to sports after anterior cruciate ligament reconstruction (ACLR). Although landing is a quick ballistic movement that is difficult to modify, squatting is a slower cyclic movement that is ideal for motor learning. Hypothesis: There is a relationship between lower extremity biomechanics during bilateral landing and bilateral squatting in patients with an ACLR. Study Design: Descriptive laboratory study. Methods: A total of 41 patients after a unilateral ACLR (24 men, 17 women; 5.9 ± 1.4 months after ACLR) completed 15 unweighted bilateral squats and 10 bilateral stop-jumps. Three-dimensional lower extremity kinematics and kinetics were collected, and peak knee abduction angle, knee abduction/adduction range of motion, peak vertical ground-reaction force limb symmetry index (LSI), vertical ground-reaction force impulse LSI, and peak knee extension moment LSI were computed during the descending phase of the squatting and landing tasks. Wilcoxon signed-rank tests were used to compare each outcome between limbs, and Spearman correlations were used to compare outcomes between the squatting and landing tasks. Results: The peak vertical ground reaction force, the vertical ground reaction force impulse, and the peak knee extension moment were reduced in the surgical (Sx) limb relative to the nonsurgical (NSx) limb during both the squatting and landing tasks (P < .001). The relationship between squatting and landing tasks was strong for the peak knee abduction angle (R = 0.697-0.737; P < .001); moderate for the frontal plane knee range of motion (NSx: R = 0.366, P = .019; Sx: R = 0.418, P = 0.007), the peak knee extension moment LSI (R = 0.573; P < .001), the vertical ground reaction force impulse LSI (R = 0.382; P < .014); and weak for the peak vertical ground reaction force LSI (R = 0.323; P = .039). Conclusion: Patients who have undergone an ACLR continue to offload their surgical limb during both squatting and landing. Additionally, there is a relationship between movement deficits during squatting and movement deficits during landing in patients with an ACLR preparing to return to sports. Clinical Relevance: As movement deficits during squatting and landing were related before return to sports, this study suggests that interventional approaches to improve squatting biomechanics may translate to improved landing biomechanics in patients with an ACLR.

Hurricane Ball Movement Analysis

The problem addressed in this paper originates from IYPT 2019 Question 6: By starting with hand rotation and using a tube to blow up towards it, two steel balls connected together can be rotated at a very high frequency and explain to explore this phenomenon. It is found in the pre-experiment that even without the use of the tube blowing, the two-steel-ball system can maintain a fairly long rotation, the kinetic energy decreases slowly, which leads to the steel ball system and the table between the pure roll without friction. The equation of motion of the steel ball system is then derived from the pure roll condition analytically, and the equation illustrates that the angle 9 of buckling of the steel ball system is related to the angular velocity of rotation co and the radius of the ball r. The experimental results are verified with good agreement with the expected results.

English

Introduction: The aim of the present study was to investigate the effects of postactivation potentiation (PAP) in vertical and horizontal jump performance in pre-pubertal children. Material and method: One hundred and nineteen children (65 girls and 54 boys; 6.8 ± 0.7 years old; 124.5 ± 6.4 cm; 25.2 ± 5.1 kg) participated in this study. This was a transversal cross-sectional study which incorporated a within-subjects repeatedmeasures design, where participants completed all protocols. The experimental procedure required four total testing, separated by one week, using a counterbalanced. This study investigated jumping performance associated with weighted jumps, lowload vertical jumps, and horizontal jumps. During two sessions the participants performed vertical jumps with and without PAP, the other two sessions the same procedures were performed for horizontal jumps. The PAP protocol consisted of one set of five weighted countermovement jumps with low-load (10% of body mass) and a rest interval of four minutes prior to the jump tests. Paired t-tests were used between conditions (PAP and control) in the vertical jump and horizontal jump test. In addition, Cohen’s d effect size and 95% confidence interval was used. Results: Significant jump height was observed in the vertical jump in the PAP condition compared to the control condition (p = 0.007). Similar results were observed for the horizontal jump tests, with significant longer distance observed in the PAP condition (p = 0.036). Conclusions: Pre-pubertal children can benefit from the effects of PAP in vertical and horizontal jumping performance when preceded by low-load ballistic movements. A protocol implementing low-loads, determined by a relative percentage of body mass is effective to promote PAP for young children.

Development of a bellows pumping device for enhancing ventilation to shake-flask systems

Shake-flask culture has been developed as an alternative to microbial surface culture. Shake-flask systems are known to affect microbial activity via composition of the headspace and ventilation ability of the culture plug. Gaseous control methods are limited to improvement of monitoring devices for shake-flask. In this study, a novel device was developed to improve ventilation in shake-flask culture without any complicated operations. This device was designed to induce a reciprocating motion of metal balls that results in the activation of the built-in bellows pump to send the outside air forcibly and aseptically into the flask gas phase. The ventilation capacity of the developed nonelectric bellows pump for shake-flask (NeBP-sf) was evaluated using the half-life of CO2 as an index. The maximum CO2 half-life of the NeBP-sf was found to be less than 10 min, and more than 5 times higher than that of the control (about 50 min). The NeBP-sf improved the ventilation capacity of shaking culture, resulting in enhanced growth of Escherichia coli compared with the control. Overall, these findings show that the developed device could have practical applications in reducing the space requirements and does not require additional electrical power to function.

Eye Tracking System using Matlab

There are many people around us who suffer from diseases like paralysis, quadriplegia due to which they cannot move their hands and legs. People suffering from such diseases need a person to be with them all the time to understand their needs and assist them. So, for their aid we want to implement an EYE DIRECTIVE WHEEL CHAIR, which moves in the direction based on the movement of eye balls of the person, helping in mobility. For this project we are designing a system called EYE TRACKING SYSTEM. This system consists of a camera, which is mounted on the wheel chair, which captures the movement of the eye balls of the person continuously. And these images are processed by a simulation software called MATLAB. This directs the motion of the EYE DIRECTIVE WHEEL CHAIR. When the person looks in a direction, the angle of rotation of the eyeball is calculated using MATLAB by processing the images continuously captured by the camera. When the person moves his eye balls in left direction, it shows to move left. Similarly, if he moves his eye balls in right direction, it shows move right. It shows move forward when eye balls or looking straight. And in every other situation it shows stop.

Intelligent Recognition System for the Curves Trajectory and Track Capture Using Artificial Intelligence Technology

Aiming at the problem of large deviation of the recognition results of the traditional recognition system, this article carried out the design and research of the intelligent recognition system of the football curve ball movement trajectory. The hardware structure design includes the acceleration sensor selection, the angular motion detection device selection and the power supply circuit design, and the software structure design includes the motion trajectory data filtering processing and the football curve ball motion speed displacement recognition. Experiments show that, compared with the traditional system, the design system has a smaller deviation of the recognition results, significantly fewer recognition errors, and higher accuracy.

Three-Dimensional Motion of Tennis Ball

Modern tennis players use a variety of strokes. From the physical point of view, these shots can be classified into eight main groups depending on the way the racket interacts with the tennis ball. These are strokes with top, bottom, side, top-side, and bottom-side rotation, as well as strokes without rotation. These eight interactions lead to eight main types of trajectories at the same initial position and the same initial linear velocity. The main purpose of the study is to determine these trajectories and to describe their advantages and disadvantages in modern competitive tennis. The calculations and graphical images are performed with the MatLab mathematical package

Simulation of Tennis Match Scene Classification Algorithm Based on Adaptive Gaussian Mixture Model Parameter Estimation

This paper presents an in-depth analysis of tennis match scene classification using an adaptive Gaussian mixture model parameter estimation simulation algorithm. We divided the main components of semantic analysis into type of motion, distance of motion, speed of motion, and landing area of the tennis ball. Firstly, for the problem that both people and tennis balls in the video frames of tennis matches from the surveillance viewpoint are very small, we propose an adaptive Gaussian mixture model parameter estimation algorithm, which has good accuracy and speed on small targets. Secondly, in this paper, we design a sports player tracking algorithm based on role division and continuously lock the target player to be tracked and output the player region. At the same time, based on the displacement information of the key points of the player’s body and the system running time, the distance and speed of the player’s movement are obtained. Then, for the problem that tennis balls are small and difficult to capture in high-speed motion, this paper designs a prior knowledge-based algorithm for predicting tennis ball motion and landing area to derive the landing area of tennis balls. Finally, this paper implements a prototype system for semantic analysis of real-time video of tennis matches and tests and analyzes the performance indexes of the system, and the results show that the system has good performance in real-time, accuracy, and stability.

The development of metrics for measuring the level of symmetry in team formation and ball movement flow, and their association with performance

ABSTRACT Objective In the current study, we examined how football players’ usage of space and the teams’ ball movement flow throughout the match are associated with the quality of performance achieved in competition. Methods We constructed two novel metrics that aimed at measuring spatial symmetry and passing flow on a team-wide scope. Our aim was to clarify whether the way players position themselves throughout the match, and the passing patterns they produce, can explain team success. Results An analysis of all matches played in the 2018–2019 English Premier League season (N = 380) revealed a positive relationship between the teams’ spatiotemporal dynamics and team performance. Conclusion Based on the findings of our analysis, we discuss the strengths and limitations of the newly-developed metrics, and stress the need for additional studies examining their effectiveness.

Target Tracking Algorithm for Table Tennis Using Machine Vision.

The current table tennis robot system has two common problems. One is the table tennis ball speed, which moves fast, and it is difficult for the robot to react in a short time. The second is that the robot cannot recognize the type of the ball's movement, i.e., rotation, top rotation, no rotation, wait, etc. It is impossible to judge whether the ball is rotating and the direction of rotation, resulting in a single return strategy of the robot with poor adaptability. In this paper, these problems are solved by proposing a target trajectory tracking algorithm for table tennis using machine vision combined with Scaled Conjugate Gradient (SCG). Real human-machine game's data are obtained in the proposed algorithm by extracting ten continuous position information and speed information frames for feature selection. These features are used as input data for the deep neural network and then are normalized to create a deep neural network algorithm model. The model is trained by the position information of the successive 20 frames. During the initial sets of experiments, we found the shortcomings of the original SCG algorithm. By setting the accuracy threshold and offline learning of historical data and saving the hidden layer weight matrix, the SCG algorithm was improved. Finally, experiments verify the improved algorithm's feasibility and applicability and show that the proposed algorithm is more suitable for table tennis robots.

An artificial intelligence that increases simulated brain–computer interface performance

Objective. Brain–computer interfaces (BCIs) translate neural activity into control signals for assistive devices in order to help people with motor disabilities communicate effectively. In this work, we introduce a new BCI architecture that improves control of a BCI computer cursor to type on a virtual keyboard. Approach. Our BCI architecture incorporates an external artificial intelligence (AI) that beneficially augments the movement trajectories of the BCI. This AI-BCI leverages past user actions, at both long (100 s of seconds ago) and short (100 s of milliseconds ago) timescales, to modify the BCI’s trajectories. Main results. We tested our AI-BCI in a closed-loop BCI simulator with nine human subjects performing a typing task. We demonstrate that our AI-BCI achieves: (1) categorically higher information communication rates, (2) quicker ballistic movements between targets, (3) improved precision control to ‘dial in’ on targets, and (4) more efficient movement trajectories. We further show that our AI-BCI increases performance across a wide control quality spectrum from poor to proficient control. Significance. This AI-BCI architecture, by increasing BCI performance across all key metrics evaluated, may increase the clinical viability of BCI systems.

Optimal escape-and-feeding dynamics of random walkers: Rethinking the convenience of ballistic strategies.

Excited random walks represent a convenient model to study food intake in a media which is progressively depleted by the walker. Trajectories in the model alternate between (i) feeding and (ii) escape (when food is missed and so it must be found again) periods, each governed by different movement rules. Here, we explore the case where the escape dynamics is adaptive, so at short times an area-restricted search is carried out, and a switch to extensive or ballistic motion occurs later if necessary. We derive for this case explicit analytical expressions of the mean escape time and the asymptotic growth of the depleted region in one dimension. These, together with numerical results in two dimensions, provide surprising evidence that ballistic searches are detrimental in such scenarios, a result which could explain why ballistic movement is barely observed in animal searches at microscopic and millimetric scales, therefore providing significant implications for biological foraging.

Simulating Extraocular Muscle Dynamics. A Comparison between Dynamic Implicit and Explicit Finite Element Methods

The finite element method has been widely used to investigate the mechanical behavior of biological tissues. When analyzing these particular materials subjected to dynamic requests, time integration algorithms should be considered to incorporate the inertial effects. These algorithms can be classified as implicit or explicit. Although both algorithms have been used in different scenarios, a comparative study of the outcomes of both methods is important to determine the performance of a model used to simulate the active contraction of the skeletal muscle tissue. In this work, dynamic implicit and dynamic explicit solutions are presented for the movement of the eye ball induced by the extraocular muscles. Aspects such as stability, computational time and the influence of mass-scaling for the explicit formulation were assessed using ABAQUS software. Both strategies produced similar results regarding range of movement of the eye ball, total deformation and kinetic energy. Using the implicit dynamic formulation, an important amount of computational time reduction is achieved. Although mass-scaling can reduce the simulation time, the dynamic contraction of the muscle is drastically altered.

Kinematics of elements of a spherical ball bearing suspension

The kinematic constraint equations of elements of a spherical ball bearing suspension, separator and balls are considered. Based on the equation of motion of the separator and the balls, the angular coordinates of the separator and the trajectory of the centers of mass of the balls relative to the bearing surfaces are determined. Analytical expressions for determining the parameters of the separator and the balls motion are obtained for different ratios between the velocities of rotation of the rotor mounted on the outer ring and the inner ring of the suspension.