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Sample records for rapid arm movements

  1. Endpoints of arm movements to visual targets

    NARCIS (Netherlands)

    van den Dobbelsteen, John; Brenner, Eli; Smeets, Jeroen B J

    2001-01-01

    Reaching out for objects with an unseen arm involves using both visual and kinesthetic information. Neither visual nor kinesthetic information is perfect. Each is subject to both constant and variable errors. To evaluate how such errors influence performance in natural goal-directed movements, we

  2. Computing Arm Movements with a Monkey Brainet.

    Science.gov (United States)

    Ramakrishnan, Arjun; Ifft, Peter J; Pais-Vieira, Miguel; Byun, Yoon Woo; Zhuang, Katie Z; Lebedev, Mikhail A; Nicolelis, Miguel A L

    2015-07-09

    Traditionally, brain-machine interfaces (BMIs) extract motor commands from a single brain to control the movements of artificial devices. Here, we introduce a Brainet that utilizes very-large-scale brain activity (VLSBA) from two (B2) or three (B3) nonhuman primates to engage in a common motor behaviour. A B2 generated 2D movements of an avatar arm where each monkey contributed equally to X and Y coordinates; or one monkey fully controlled the X-coordinate and the other controlled the Y-coordinate. A B3 produced arm movements in 3D space, while each monkey generated movements in 2D subspaces (X-Y, Y-Z, or X-Z). With long-term training we observed increased coordination of behavior, increased correlations in neuronal activity between different brains, and modifications to neuronal representation of the motor plan. Overall, performance of the Brainet improved owing to collective monkey behaviour. These results suggest that primate brains can be integrated into a Brainet, which self-adapts to achieve a common motor goal.

  3. Kinematic decomposition and classification of octopus arm movements

    OpenAIRE

    Zelman, Ido; Titon, Myriam; Yekutieli, Yoram; Hanassy, Shlomi; Hochner, Binyamin; Flash, Tamar

    2013-01-01

    The octopus arm is a muscular hydrostat and due to its deformable and highly flexible structure it is capable of a rich repertoire of motor behaviors. Its motor control system uses planning principles and control strategies unique to muscular hydrostats. We previously reconstructed a data set of octopus arm movements from records of natural movements using a sequence of 3D curves describing the virtual backbone of arm configurations. Here we describe a novel representation of octopus arm move...

  4. Kinematic decomposition and classification of octopus arm movements.

    Science.gov (United States)

    Zelman, Ido; Titon, Myriam; Yekutieli, Yoram; Hanassy, Shlomi; Hochner, Binyamin; Flash, Tamar

    2013-01-01

    The octopus arm is a muscular hydrostat and due to its deformable and highly flexible structure it is capable of a rich repertoire of motor behaviors. Its motor control system uses planning principles and control strategies unique to muscular hydrostats. We previously reconstructed a data set of octopus arm movements from records of natural movements using a sequence of 3D curves describing the virtual backbone of arm configurations. Here we describe a novel representation of octopus arm movements in which a movement is characterized by a pair of surfaces that represent the curvature and torsion values of points along the arm as a function of time. This representation allowed us to explore whether the movements are built up of elementary kinematic units by decomposing each surface into a weighted combination of 2D Gaussian functions. The resulting Gaussian functions can be considered as motion primitives at the kinematic level of octopus arm movements. These can be used to examine underlying principles of movement generation. Here we used combination of such kinematic primitives to decompose different octopus arm movements and characterize several movement prototypes according to their composition. The representation and methodology can be applied to the movement of any organ which can be modeled by means of a continuous 3D curve.

  5. Kinematic decomposition and classification of octopus arm movements

    Directory of Open Access Journals (Sweden)

    Ido eZelman

    2013-05-01

    Full Text Available The octopus arm is a muscular hydrostat and due to its deformable and highly flexible structure it is capable of a rich repertoire of motor behaviors. Its motor control system uses planning principles and control strategies unique to muscular hydrostats. We previously reconstructed a data set of octopus arm movements from records of natural movements using a sequence of 3D curves describing the virtual backbone of arm configurations. Here we describe a novel representation of octopus arm movements in which a movement is characterized by a pair of surfaces that represent the curvature and torsion values of points along the arm as a function of time. This representation allowed us to explore whether the movements are built up of elementary kinematic units by decomposing each surface into a weighted combination of 2D Gaussian functions. The resulting Gaussian functions can be considered as motion primitives at the kinematic level of octopus arm movements. These can be used to examine underlying principles of movement generation. Here we used combination of such kinematic primitives to decompose different octopus arm movements and characterize several movement prototypes according to their composition. The representation and methodology can be applied to the movement of any organ which can be modeled by means of a continuous 3D curve.

  6. Bilateral movements increase sustained extensor force in the paretic arm.

    Science.gov (United States)

    Kang, Nyeonju; Cauraugh, James H

    2018-04-01

    Muscle weakness in the extensors poststroke is a common motor impairment. Unfortunately, research is unclear on whether bilateral movements increase extensor force production in the paretic arm. This study investigated sustained force production while stroke individuals maximally extended their wrist and fingers on their paretic arm. Specifically, we determined isometric force production in three conditions: (a) unilateral paretic arm, (b) unilateral nonparetic arm, and (c) bilateral (both arms executing the same movement simultaneously). Seventeen chronic stroke patients produced isometric sustained force by executing wrist and fingers extension in unilateral and bilateral contraction conditions. Mean force, force variability (coefficient of variation), and signal-to-noise ratio were calculated for each contraction condition. Analysis of two-way (Arm × Type of Condition: 2 × 2; Paretic or Nonparetic Arm × Unilateral or Bilateral Conditions) within-subjects ANOVAs revealed that the bilateral condition increased sustained force in the paretic arm, but reduced sustained force in the nonparetic arm. Further, although the paretic arm exhibited more force variability and less signal-to-noise ratio than the nonparetic arm during a unilateral condition, there were no differences when participants simultaneously executed isometric contractions with both arms. Our unique findings indicate that bilateral contractions transiently increased extensor force in the paretic arm. Implications for Rehabilitation Bilateral movements increased isometric wrsit extensor force in paretic arms and redcued force in nonparetic arms versus unilateral movements. Both paretic and nonparetic arms produced similar force variability and signal-to-noise ratio during bilateral movements. Increased sustained force in the paretic arm during the bilateral condition indicates that rehabilitation protocols based on bilateral movements may be beneficial for functional recovery.

  7. Organization of octopus arm movements: a model system for studying the control of flexible arms.

    Science.gov (United States)

    Gutfreund, Y; Flash, T; Yarom, Y; Fiorito, G; Segev, I; Hochner, B

    1996-11-15

    Octopus arm movements provide an extreme example of controlled movements of a flexible arm with virtually unlimited degrees of freedom. This study aims to identify general principles in the organization of these movements. Video records of the movements of Octopus vulgaris performing the task of reaching toward a target were studied. The octopus extends its arm toward the target by a wave-like propagation of a bend that travels from the base of the arm toward the tip. Similar bend propagation is seen in other octopus arm movements, such as locomotion and searching. The kinematics (position and velocity) of the midpoint of the bend in three-dimensional space were extracted using the direct linear transformation algorithm. This showed that the bend tends to move within a single linear plane in a simple, slightly curved path connecting the center of the animal's body with the target location. Approximately 70% of the reaching movements demonstrated a stereotyped tangential velocity profile. An invariant profile was observed when movements were normalized for velocity and distance. Two arms, extended together in the same behavioral context, demonstrated identical velocity profiles. The stereotyped features of the movements were also observed in spontaneous arm extensions (not toward an external target). The simple and stereotypic appearance of the bend trajectory suggests that the position of the bend in space and time is the controlled variable. We propose that this strategy reduces the immense redundancy of the octopus arm movements and hence simplifies motor control.

  8. Patterns of arm muscle activation involved in octopus reaching movements.

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    Gutfreund, Y; Flash, T; Fiorito, G; Hochner, B

    1998-08-01

    The extreme flexibility of the octopus arm allows it to perform many different movements, yet octopuses reach toward a target in a stereotyped manner using a basic invariant motor structure: a bend traveling from the base of the arm toward the tip (Gutfreund et al., 1996a). To study the neuronal control of these movements, arm muscle activation [electromyogram (EMG)] was measured together with the kinematics of reaching movements. The traveling bend is associated with a propagating wave of muscle activation, with maximal muscle activation slightly preceding the traveling bend. Tonic activation was occasionally maintained afterward. Correlation of the EMG signals with the kinematic variables (velocities and accelerations) reveals that a significant part of the kinematic variability can be explained by the level of muscle activation. Furthermore, the EMG level measured during the initial stages of movement predicts the peak velocity attained toward the end of the reaching movement. These results suggest that feed-forward motor commands play an important role in the control of movement velocity and that simple adjustment of the excitation levels at the initial stages of the movement can set the velocity profile of the whole movement. A simple model of octopus arm extension is proposed in which the driving force is set initially and is then decreased in proportion to arm diameter at the bend. The model qualitatively reproduces the typical velocity profiles of octopus reaching movements, suggesting a simple control mechanism for bend propagation in the octopus arm.

  9. Brain-Machine Interface Enables Bimanual Arm Movements in Monkeys

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    Ifft, Peter J.; Shokur, Solaiman; Li, Zheng; Lebedev, Mikhail A.; Nicolelis, Miguel A. L.

    2014-01-01

    Brain-machine interfaces (BMIs) are artificial systems that aim to restore sensation and movement to severely paralyzed patients. However, previous BMIs enabled only single arm functionality, and control of bimanual movements was a major challenge. Here, we developed and tested a bimanual BMI that enabled rhesus monkeys to control two avatar arms simultaneously. The bimanual BMI was based on the extracellular activity of 374–497 neurons recorded from several frontal and parietal cortical areas of both cerebral hemispheres. Cortical activity was transformed into movements of the two arms with a decoding algorithm called a 5th order unscented Kalman filter (UKF). The UKF is well-suited for BMI decoding because it accounts for both characteristics of reaching movements and their representation by cortical neurons. The UKF was trained either during a manual task performed with two joysticks or by having the monkeys passively observe the movements of avatar arms. Most cortical neurons changed their modulation patterns when both arms were engaged simultaneously. Representing the two arms jointly in a single UKF decoder resulted in improved decoding performance compared with using separate decoders for each arm. As the animals’ performance in bimanual BMI control improved over time, we observed widespread plasticity in frontal and parietal cortical areas. Neuronal representation of the avatar and reach targets was enhanced with learning, whereas pairwise correlations between neurons initially increased and then decreased. These results suggest that cortical networks may assimilate the two avatar arms through BMI control. PMID:24197735

  10. Rapid eye movement sleep behavior disorder

    DEFF Research Database (Denmark)

    Schenck, C H; Montplaisir, J Y; Frauscher, B

    2013-01-01

    We aimed to provide a consensus statement by the International Rapid Eye Movement Sleep Behavior Disorder Study Group (IRBD-SG) on devising controlled active treatment studies in rapid eye movement sleep behavior disorder (RBD) and devising studies of neuroprotection against Parkinson disease (PD...

  11. Degeneration of rapid eye movement sleep circuitry underlies rapid eye movement sleep behavior disorder.

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    McKenna, Dillon; Peever, John

    2017-05-01

    During healthy rapid eye movement sleep, skeletal muscles are actively forced into a state of motor paralysis. However, in rapid eye movement sleep behavior disorder-a relatively common neurological disorder-this natural process is lost. A lack of motor paralysis (atonia) in rapid eye movement sleep behavior disorder allows individuals to actively move, which at times can be excessive and violent. At first glance this may sound harmless, but it is not because rapid eye movement sleep behavior disorder patients frequently injure themselves or the person they sleep with. It is hypothesized that the degeneration or dysfunction of the brain stem circuits that control rapid eye movement sleep paralysis is an underlying cause of rapid eye movement sleep behavior disorder. The link between brain stem degeneration and rapid eye movement sleep behavior disorder stems from the fact that rapid eye movement sleep behavior disorder precedes, in the majority (∼80%) of cases, the development of synucleinopathies such as Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy, which are known to initially cause degeneration in the caudal brain stem structures where rapid eye movement sleep circuits are located. Furthermore, basic science and clinical evidence demonstrate that lesions within the rapid eye movement sleep circuits can induce rapid eye movement sleep-specific motor deficits that are virtually identical to those observed in rapid eye movement sleep behavior disorder. This review examines the evidence that rapid eye movement sleep behavior disorder is caused by synucleinopathic neurodegeneration of the core brain stem circuits that control healthy rapid eye movement sleep and concludes that rapid eye movement sleep behavior disorder is not a separate clinical entity from synucleinopathies but, rather, it is the earliest symptom of these disorders. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and

  12. Frictional Sound Analysis by Simulating the Human Arm Movement

    Directory of Open Access Journals (Sweden)

    Yosouf Khaldon

    2017-03-01

    Full Text Available Fabric noise generated by fabric-to-fabric friction is considered as one of the auditory disturbances that can have an impact on the quality of some textile products. For this reason, an instrument has been developed to analyse this phenomenon. The instrument is designed to simulate the relative movement of a human arm when walking. In order to understand the nature of the relative motion of a human arm, films of the upper half of the human body were taken. These films help to define the parameters required for movement simulation. These parameters are movement trajectory, movement velocity, arm pressure applied on the lateral part of the trunk and the friction area. After creating the instrument, a set of soundtracks related to the noise generated by fabric-to-fabric friction was recorded. The recordings were treated with a specific software to extract the sound parameters and the acoustic imprints of fabric were obtained.

  13. A Neuro-Fuzzy System for Characterization of Arm Movements

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    Alexandre Balbinot

    2013-02-01

    Full Text Available The myoelectric signal reflects the electrical activity of skeletal muscles and contains information about the structure and function of the muscles which make different parts of the body move. Advances in engineering have extended electromyography beyond the traditional diagnostic applications to also include applications in diverse areas such as rehabilitation, movement analysis and myoelectric control of prosthesis. This paper aims to study and develop a system that uses myoelectric signals, acquired by surface electrodes, to characterize certain movements of the human arm. To recognize certain hand-arm segment movements, was developed an algorithm for pattern recognition technique based on neuro-fuzzy, representing the core of this research. This algorithm has as input the preprocessed myoelectric signal, to disclosed specific characteristics of the signal, and as output the performed movement. The average accuracy obtained was 86% to 7 distinct movements in tests of long duration (about three hours.

  14. Repetitive Arm Movements During Sleep: A Polysomnographic Assessment

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    Mohammad Torabi-Nami

    2016-07-01

    Full Text Available Sleep-related movement disorders should be differentiated from parasomnias, sleep-associated behavioral disorders, and epilepsy. Polysomnography (PSG is the gold standard in evaluating such disorders. Periodic leg movement disorder during sleep (PLMS, hypnic jerks, bruxism, rhythmic movement disorder, restless legs syndrome, and nocturnal leg cramps have broadly been discussed in the literature. However, periodic arm movement disorder in sleep (PAMS is a less-appreciated entity perhaps because arm surface electromyography is not an integral part of the standard polysomnography. Results from our PSG study in a case suspected for PAMS prompted us to herewith discuss this problem.

  15. Kinematic feedback control laws for generating natural arm movements

    International Nuclear Information System (INIS)

    Kim, Donghyun; Jang, Cheongjae; Park, Frank C

    2014-01-01

    We propose a stochastic optimal feedback control law for generating natural robot arm motions. Our approach, inspired by the minimum variance principle of Harris and Wolpert (1998 Nature 394 780–4) and the optimal feedback control principles put forth by Todorov and Jordan (2002 Nature Neurosci. 5 1226–35) for explaining human movements, differs in two crucial respects: (i) the endpoint variance is minimized in joint space rather than Cartesian hand space, and (ii) we ignore the dynamics and instead consider only the second-order differential kinematics. The feedback control law generating the motions can be straightforwardly obtained by backward integration of a set of ordinary differential equations; these equations are obtained exactly, without any linear–quadratic approximations. The only parameters to be determined a priori are the variance scale factors, and for both the two-DOF planar arm and the seven-DOF spatial arm, a table of values is constructed based on the given initial and final arm configurations; these values are determined via an optimal fitting procedure, and consistent with existing findings about neuromuscular motor noise levels of human arm muscles. Experiments conducted with a two-link planar arm and a seven-DOF spatial arm verify that the trajectories generated by our feedback control law closely resemble human arm motions, in the sense of producing nearly straight-line hand trajectories, having bell-shaped velocity profiles, and satisfying Fitts Law. (paper)

  16. Invertebrate neurobiology: visual direction of arm movements in an octopus.

    Science.gov (United States)

    Niven, Jeremy E

    2011-03-22

    An operant task in which octopuses learn to locate food by a visual cue in a three-choice maze shows that they are capable of integrating visual and mechanosensory information to direct their arm movements to a goal. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Locomotor-like leg movements evoked by rhythmic arm movements in humans.

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    Francesca Sylos-Labini

    Full Text Available Motion of the upper limbs is often coupled to that of the lower limbs in human bipedal locomotion. It is unclear, however, whether the functional coupling between upper and lower limbs is bi-directional, i.e. whether arm movements can affect the lumbosacral locomotor circuitry. Here we tested the effects of voluntary rhythmic arm movements on the lower limbs. Participants lay horizontally on their side with each leg suspended in an unloading exoskeleton. They moved their arms on an overhead treadmill as if they walked on their hands. Hand-walking in the antero-posterior direction resulted in significant locomotor-like movements of the legs in 58% of the participants. We further investigated quantitatively the responses in a subset of the responsive subjects. We found that the electromyographic (EMG activity of proximal leg muscles was modulated over each cycle with a timing similar to that of normal locomotion. The frequency of kinematic and EMG oscillations in the legs typically differed from that of arm oscillations. The effect of hand-walking was direction specific since medio-lateral arm movements did not evoke appreciably leg air-stepping. Using externally imposed trunk movements and biomechanical modelling, we ruled out that the leg movements associated with hand-walking were mainly due to the mechanical transmission of trunk oscillations. EMG activity in hamstring muscles associated with hand-walking often continued when the leg movements were transiently blocked by the experimenter or following the termination of arm movements. The present results reinforce the idea that there exists a functional neural coupling between arm and legs.

  18. Rapid eye movement sleep behavior disorder

    DEFF Research Database (Denmark)

    Zoetmulder, Marielle; Jennum, Poul

    2009-01-01

    Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by loss of REM sleep and related electromyographic atonia with marked muscular activity and dream enactment behaviour. RBD is seen in 0.5% of the population. It occurs in an idiopathic form and secondarily to medical...

  19. A biologically inspired neural network controller for ballistic arm movements

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    Schmid Maurizio

    2007-09-01

    Full Text Available Abstract Background In humans, the implementation of multijoint tasks of the arm implies a highly complex integration of sensory information, sensorimotor transformations and motor planning. Computational models can be profitably used to better understand the mechanisms sub-serving motor control, thus providing useful perspectives and investigating different control hypotheses. To this purpose, the use of Artificial Neural Networks has been proposed to represent and interpret the movement of upper limb. In this paper, a neural network approach to the modelling of the motor control of a human arm during planar ballistic movements is presented. Methods The developed system is composed of three main computational blocks: 1 a parallel distributed learning scheme that aims at simulating the internal inverse model in the trajectory formation process; 2 a pulse generator, which is responsible for the creation of muscular synergies; and 3 a limb model based on two joints (two degrees of freedom and six muscle-like actuators, that can accommodate for the biomechanical parameters of the arm. The learning paradigm of the neural controller is based on a pure exploration of the working space with no feedback signal. Kinematics provided by the system have been compared with those obtained in literature from experimental data of humans. Results The model reproduces kinematics of arm movements, with bell-shaped wrist velocity profiles and approximately straight trajectories, and gives rise to the generation of synergies for the execution of movements. The model allows achieving amplitude and direction errors of respectively 0.52 cm and 0.2 radians. Curvature values are similar to those encountered in experimental measures with humans. The neural controller also manages environmental modifications such as the insertion of different force fields acting on the end-effector. Conclusion The proposed system has been shown to properly simulate the development of

  20. Phase-dependent organization of postural adjustments associated with arm movements while walking.

    Science.gov (United States)

    Nashner, L M; Forssberg, H

    1986-06-01

    This study examines the interactions between anteroposterior postural responses and the control of walking in human subjects. In the experimental paradigm, subjects walked upon a treadmill, gripping a rigid handle with one hand. Postural responses at different phases of stepping were elicited by rapid arm pulls or pushes against the handle. During arm movements, EMG's recorded the activity of representative arm, ankle, and thigh segment muscles. Strain gauges in the handle measured the force of the arm movement. A Selspot II system measured kinematics of the stepping movements. The duration of support and swing phases were marked by heel and toe switches in the soles of the subjects' shoes. In the first experiment, subjects were instructed to pull on the handle at their own pace. In these trials all subjects preferred to initiate pulls near heel strikes. Next, when instructed to pull as rapidly as possible in response to tone stimuli, reaction times were similar for all phases of the step cycle. Leg muscle responses associated with arm pulls and pushes, referred to as "postural activations," were directionally specific and preceded arm muscle activity. The temporal order and spatial distribution of postural activations in the muscles of the support leg were similar when arm pull movements occurred while the subject was standing in place and after heel strike while walking. Activations began in the ankle and radiated proximally to the thigh and then the arm. Activations of swing leg muscles were also directionally specific and involved flexion and forward or backward thrust of the limb. When arm movements were initiated during transitions from support by one leg to the other, patterns of postural activations were altered. Alterations usually occurred 10-20 ms before hell strikes and involved changes in the timing and sometimes the spatial structure of postural activations. Postural activation patterns are similar during in-place standing and during the support phase

  1. Research on the Optimization Method of Arm Movement in the Assembly Workshop Based on Ergonomics

    Science.gov (United States)

    Hu, X. M.; Qu, H. W.; Xu, H. J.; Yang, L.; Yu, C. C.

    2017-12-01

    In order to improve the work efficiency and comfortability, Ergonomics is used to research the work of the operator in the assembly workshop. An optimization algorithm of arm movement in the assembly workshop is proposed. In the algorithm, a mathematical model of arm movement is established based on multi rigid body movement model and D-H method. The solution of inverse kinematics equation on arm movement is solved through kinematics theory. The evaluation functions of each joint movement and the whole arm movement are given based on the comfortability of human body joint. The solution method of the optimal arm movement posture based on the evaluation functions is described. The software CATIA is used to verify that the optimal arm movement posture is valid in an example and the experimental result show the effectiveness of the algorithm.

  2. Laboratory Validation of Inertial Body Sensors to Detect Cigarette Smoking Arm Movements

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    Bethany R. Raiff

    2014-02-01

    Full Text Available Cigarette smoking remains the leading cause of preventable death in the United States. Traditional in-clinic cessation interventions may fail to intervene and interrupt the rapid progression to relapse that typically occurs following a quit attempt. The ability to detect actual smoking behavior in real-time is a measurement challenge for health behavior research and intervention. The successful detection of real-time smoking through mobile health (mHealth methodology has substantial implications for developing highly efficacious treatment interventions. The current study was aimed at further developing and testing the ability of inertial sensors to detect cigarette smoking arm movements among smokers. The current study involved four smokers who smoked six cigarettes each in a laboratory-based assessment. Participants were outfitted with four inertial body movement sensors on the arms, which were used to detect smoking events at two levels: the puff level and the cigarette level. Two different algorithms (Support Vector Machines (SVM and Edge-Detection based learning were trained to detect the features of arm movement sequences transmitted by the sensors that corresponded with each level. The results showed that performance of the SVM algorithm at the cigarette level exceeded detection at the individual puff level, with low rates of false positive puff detection. The current study is the second in a line of programmatic research demonstrating the proof-of-concept for sensor-based tracking of smoking, based on movements of the arm and wrist. This study demonstrates efficacy in a real-world clinical inpatient setting and is the first to provide a detection rate against direct observation, enabling calculation of true and false positive rates. The study results indicate that the approach performs very well with some participants, whereas some challenges remain with participants who generate more frequent non-smoking movements near the face. Future

  3. Movement Structure in Young and Elderly Adults during Goal-Directed Movements of the Left and Right Arm

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    Poston, Brach; Van Gemmert, Arend W. A.; Barduson, Beth; Stelmach, George E.

    2009-01-01

    Elderly adults often exhibit performance deficits during goal-directed movements of the dominant arm compared with young adults. Recent studies involving hemispheric lateralization have provided evidence that the dominant and non-dominant hemisphere-arm systems are specialized for controlling different movement parameters and that hemispheric…

  4. Human movement training with a cable driven ARm EXoskeleton (CAREX).

    Science.gov (United States)

    Mao, Ying; Jin, Xin; Gera Dutta, Geetanjali; Scholz, John P; Agrawal, Sunil K

    2015-01-01

    In recent years, the authors have proposed lightweight exoskeleton designs for upper arm rehabilitation using multi-stage cable-driven parallel mechanism. Previously, the authors have demonstrated via experiments that it is possible to apply "assist-as-needed" forces in all directions at the end-effector with such an exoskeleton acting on an anthropomorphic machine arm. A human-exoskeleton interface was also presented to show the feasibility of CAREX on human subjects. The goals of this paper are to 1) further address issues when CAREX is mounted on human subjects, e.g., generation of continuous cable tension trajectories 2) demonstrate the feasibility and effectiveness of CAREX on movement training of healthy human subjects and a stroke patient. In this research, CAREX is rigidly attached to an arm orthosis worn by human subjects. The cable routing points are optimized to achieve a relatively large "tensioned" static workspace. A new cable tension planner based on quadratic programming is used to generate continuous cable tension trajectory for smooth motion. Experiments were carried out on eight healthy subjects. The experimental results show that CAREX can help the subjects move closer to a prescribed circular path using the force fields generated by the exoskeleton. The subjects also adapt to the path shortly after training. CAREX was also evaluated on a stroke patient to test the feasibility of its use on patients with neural impairment. The results show that the patient was able to move closer to a prescribed straight line path with the "assist-as-needed" force field.

  5. The timing of control signals underlying fast point-to-point arm movements.

    Science.gov (United States)

    Ghafouri, M; Feldman, A G

    2001-04-01

    on the handle, or computed with equations of motion. In some trials, an electromagnetic brake prevented movements. In such movements, the hand force and joint torques reached a steady state after a time that was much smaller than the movement duration in unobstructed movements and was approximately equal to the time to peak velocity (mean difference hypothesis that, in unobstructed movements, the IC shifts and resulting shifts in the EP end approximately at peak velocity. In other words, during the latter part of the movement, the control signals responsible for the equilibrium shift remained constant, and the movement was driven by the arm inertial, viscous and elastic forces produced by the muscle-reflex system. Fast movements may thus be completed without continuous control guidance. As a consequence, central corrections and sequential commands may be issued rapidly, without waiting for the end of kinematic responses to each command, which may be important for many motor behaviours including typing, piano playing and speech. Our study also illustrates that the timing of the control signals may be substantially different from that of the resulting motor output and that the same control pattern may produce different motor outputs depending on external conditions.

  6. Everyday movement and use of the arms: Relationship in children with hemiparesis differs from adults.

    Science.gov (United States)

    Sokal, Brad; Uswatte, Gitendra; Vogtle, Laura; Byrom, Ezekiel; Barman, Joydip

    2015-01-01

    In adults with hemiparesis amount of movement of the more-affected arm is related to its amount of use in daily life. In children, little is known about everyday arm use. This report examines the relationships between everyday movement of the more-affected arm and its (a) everyday use and (b) motor capacity in children with hemiparesis. Participants were 28 children with a wide range of upper-extremity hemiparesis subsequent to cerebral palsy due to pre- or peri-natal stroke. Everyday movement of the more-affected arm was assessed by putting accelerometers on the children's forearms for three days. Everyday use of that arm and its motor capacity were assessed with the Pediatric Motor Activity Log-Revised and Pediatric Arm Function Test, respectively. Intensity of everyday movement of the more-affected arm was correlated with its motor capacity (rs ≥ 0.52, ps ≤ 0.003). However, everyday movement of that arm was not correlated with its everyday use (rs ≤ 0.30, ps ≥ $ 0.126). In children with upper-extremity hemiparesis who meet the study intake criteria amount of movement of the more-affected arm in daily life is not related to its amount to use, suggesting that children differ from adults in this respect.

  7. Stereotypical reaching movements of the octopus involve both bend propagation and arm elongation.

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    Hanassy, S; Botvinnik, A; Flash, T; Hochner, B

    2015-05-13

    The bend propagation involved in the stereotypical reaching movement of the octopus arm has been extensively studied. While these studies have analyzed the kinematics of bend propagation along the arm during its extension, possible length changes have been ignored. Here, the elongation profiles of the reaching movements of Octopus vulgaris were assessed using three-dimensional reconstructions. The analysis revealed that, in addition to bend propagation, arm extension movements involve elongation of the proximal part of the arm, i.e., the section from the base of the arm to the propagating bend. The elongations are quite substantial and highly variable, ranging from an average strain along the arm of -0.12 (i.e. shortening) up to 1.8 at the end of the movement (0.57 ± 0.41, n = 64 movements, four animals). Less variability was discovered in an additional set of experiments on reaching movements (0.64 ± 0.28, n = 30 movements, two animals), where target and octopus positions were kept more stationary. Visual observation and subsequent kinematic analysis suggest that the reaching movements can be broadly segregated into two groups. The first group involves bend propagation beginning at the base of the arm and propagating towards the arm tip. In the second, the bend is formed or present more distally and reaching is achieved mainly by elongation and straightening of the segment proximal to the bend. Only in the second type of movements is elongation significantly positively correlated with the distance of the bend from the target. We suggest that reaching towards a target is generated by a combination of both propagation of a bend along the arm and arm elongation. These two motor primitives may be combined to create a broad spectrum of reaching movements. The dynamical model, which recapitulates the biomechanics of the octopus muscular hydrostatic arm, suggests that achieving the observed elongation requires an extremely low ratio of longitudinal to transverse muscle

  8. Fuzzy-Genetic Optimal Control for Four Degreeof Freedom Robotic Arm Movement

    OpenAIRE

    V. K. Banga; R. Kumar; Y. Singh

    2009-01-01

    In this paper, we present optimal control for movement and trajectory planning for four degrees-of-freedom robot using Fuzzy Logic (FL) and Genetic Algorithms (GAs). We have evaluated using Fuzzy Logic (FL) and Genetic Algorithms (GAs) for four degree-of-freedom (4 DOF) robotics arm, Uncertainties like; Movement, Friction and Settling Time in robotic arm movement have been compensated using Fuzzy logic and Genetic Algorithms. The development of a fuzzy genetic optimizatio...

  9. Dynamic model of the octopus arm. II. Control of reaching movements.

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    Yekutieli, Yoram; Sagiv-Zohar, Roni; Hochner, Binyamin; Flash, Tamar

    2005-08-01

    The dynamic model of the octopus arm described in the first paper of this 2-part series was used here to investigate the neural strategies used for controlling the reaching movements of the octopus arm. These are stereotypical extension movements used to reach toward an object. In the dynamic model, sending a simple propagating neural activation signal to contract all muscles along the arm produced an arm extension with kinematic properties similar to those of natural movements. Control of only 2 parameters fully specified the extension movement: the amplitude of the activation signal (leading to the generation of muscle force) and the activation traveling time (the time the activation wave takes to travel along the arm). We found that the same kinematics could be achieved by applying activation signals with different activation amplitudes all exceeding some minimal level. This suggests that the octopus arm could use minimal amplitudes of activation to generate the minimal muscle forces required for the production of the desired kinematics. Larger-amplitude signals would generate larger forces that increase the arm's stability against perturbations without changing the kinematic characteristics. The robustness of this phenomenon was demonstrated by examining activation signals with either a constant or a bell-shaped velocity profile. Our modeling suggests that the octopus arm biomechanics may allow independent control of kinematics and resistance to perturbation during arm extension movements.

  10. Dynamic model of the octopus arm. I. Biomechanics of the octopus reaching movement.

    Science.gov (United States)

    Yekutieli, Yoram; Sagiv-Zohar, Roni; Aharonov, Ranit; Engel, Yaakov; Hochner, Binyamin; Flash, Tamar

    2005-08-01

    The octopus arm requires special motor control schemes because it consists almost entirely of muscles and lacks a rigid skeletal support. Here we present a 2D dynamic model of the octopus arm to explore possible strategies of movement control in this muscular hydrostat. The arm is modeled as a multisegment structure, each segment containing longitudinal and transverse muscles and maintaining a constant volume, a prominent feature of muscular hydrostats. The input to the model is the degree of activation of each of its muscles. The model includes the external forces of gravity, buoyancy, and water drag forces (experimentally estimated here). It also includes the internal forces generated by the arm muscles and the forces responsible for maintaining a constant volume. Using this dynamic model to investigate the octopus reaching movement and to explore the mechanisms of bend propagation that characterize this movement, we found the following. 1) A simple command producing a wave of muscle activation moving at a constant velocity is sufficient to replicate the natural reaching movements with similar kinematic features. 2) The biomechanical mechanism that produces the reaching movement is a stiffening wave of muscle contraction that pushes a bend forward along the arm. 3) The perpendicular drag coefficient for an octopus arm is nearly 50 times larger than the tangential drag coefficient. During a reaching movement, only a small portion of the arm is oriented perpendicular to the direction of movement, thus minimizing the drag force.

  11. Influence of arm movement on central tip location of peripherally inserted central catheters (PICCs)

    International Nuclear Information System (INIS)

    Connolly, Bairbre; Amaral, Joao; Walsh, Sharon; Temple, Michael; Chait, Peter; Stephens, Derek

    2006-01-01

    PICCs are increasingly employed in children. Some of their risks relate to the location of the central tip. Despite care when placing lines, they sometimes move. To evaluate the influence of arm movement on the central tip location of PICCs placed in children. The central tip location of PICCs was studied in 85 children, with the arm placed in six positions. The variables of side, vein, site and arm position were examined to measure the direction and range of tip movement. The side, site or vein used did not influence the range of movement of the central tip. Change in position of the arm had a significant influence on the central tip location, moving it an average of 2.2 rib spaces, a maximum of 3.5 ribs. Elbow bending and adduction of the arm caused the central tip to move deeper into the chest, compared to when the arm was straight and abducted 90 . Arm position is the significant variable influencing PICC movement. Side, site and vein do not influence the range of movement significantly. Most PICCs descend deeper into the chest with arm adduction and elbow bending. (orig.)

  12. Rapid eye movement sleep behavior disorder and rapid eye movement sleep without atonia in narcolepsy

    DEFF Research Database (Denmark)

    Dauvilliers, Yves; Jennum, Poul; Plazzi, Giuseppe

    2013-01-01

    Narcolepsy is a rare disabling hypersomnia disorder that may include cataplexy, sleep paralysis, hypnagogic hallucinations, and sleep-onset rapid eye movement (REM) periods, but also disrupted nighttime sleep by nocturnal awakenings, and REM sleep behavior disorder (RBD). RBD is characterized...... by dream-enacting behavior and impaired motor inhibition during REM sleep (REM sleep without atonia, RSWA). RBD is commonly associated with neurodegenerative disorders including Parkinsonisms, but is also reported in narcolepsy in up to 60% of patients. RBD in patients with narcolepsy is, however...... with narcolepsy often present dissociated sleep features including RSWA, increased density of phasic chin EMG and frequent shift from REM to NREM sleep, with or without associated clinical RBD. Most patients with narcolepsy with cataplexy lack the hypocretin neurons in the lateral hypothalamus. Tonic and phasic...

  13. Experimental measure of arm stiffness during single reaching movements with a time-frequency analysis

    OpenAIRE

    Piovesan, Davide; Pierobon, Alberto; DiZio, Paul; Lackner, James R.

    2013-01-01

    We tested an innovative method to estimate joint stiffness and damping during multijoint unfettered arm movements. The technique employs impulsive perturbations and a time-frequency analysis to estimate the arm's mechanical properties along a reaching trajectory. Each single impulsive perturbation provides a continuous estimation on a single-reach basis, making our method ideal to investigate motor adaptation in the presence of force fields and to study the control of movement in impaired ind...

  14. Different temporal bases for body and arm movements in volleyball serve reception

    NARCIS (Netherlands)

    Benerink, N. H.; Bootsma, R. J.; Zaal, F. T. J. M.

    2015-01-01

    In many sports, successfully intercepting a ball requires players to move both their body and their arms. Yet, studies of interception typically focus on one or the other. We performed an analysis of the moments of first foot and arm movements of elite-level volleyball players during serve

  15. Human arm stiffness and equilibrium-point trajectory during multi-joint movement.

    Science.gov (United States)

    Gomi, H; Kawato, M

    1997-03-01

    By using a newly designed high-performance manipulandum and a new estimation algorithm, we measured human multi-joint arm stiffness parameters during multi-joint point-to-point movements on a horizontal plane. This manipulandum allows us to apply a sufficient perturbation to subject's arm within a brief period during movement. Arm stiffness parameters were reliably estimated using a new algorithm, in which all unknown structural parameters could be estimated independent of arm posture (i.e., constant values under any arm posture). Arm stiffness during transverse movement was considerably greater than that during corresponding posture, but not during a longitudinal movement. Although the ratios of elbow, shoulder, and double-joint stiffness were varied in time, the orientation of stiffness ellipses during the movement did not change much. Equilibrium-point trajectories that were predicted from measured stiffness parameters and actual trajectories were slightly sinusoidally curved in Cartesian space and their velocity profiles were quite different from the velocity profiles of actual hand trajectories. This result contradicts the hypothesis that the brain does not take the dynamics into account in movement control depending on the neuromuscular servo mechanism; rather, it implies that the brain needs to acquire some internal models of controlled objects.

  16. Nearly automatic motion capture system for tracking octopus arm movements in 3D space.

    Science.gov (United States)

    Zelman, Ido; Galun, Meirav; Akselrod-Ballin, Ayelet; Yekutieli, Yoram; Hochner, Binyamin; Flash, Tamar

    2009-08-30

    Tracking animal movements in 3D space is an essential part of many biomechanical studies. The most popular technique for human motion capture uses markers placed on the skin which are tracked by a dedicated system. However, this technique may be inadequate for tracking animal movements, especially when it is impossible to attach markers to the animal's body either because of its size or shape or because of the environment in which the animal performs its movements. Attaching markers to an animal's body may also alter its behavior. Here we present a nearly automatic markerless motion capture system that overcomes these problems and successfully tracks octopus arm movements in 3D space. The system is based on three successive tracking and processing stages. The first stage uses a recently presented segmentation algorithm to detect the movement in a pair of video sequences recorded by two calibrated cameras. In the second stage, the results of the first stage are processed to produce 2D skeletal representations of the moving arm. Finally, the 2D skeletons are used to reconstruct the octopus arm movement as a sequence of 3D curves varying in time. Motion tracking, segmentation and reconstruction are especially difficult problems in the case of octopus arm movements because of the deformable, non-rigid structure of the octopus arm and the underwater environment in which it moves. Our successful results suggest that the motion-tracking system presented here may be used for tracking other elongated objects.

  17. Analysis of reaching movements of upper arm in robot assisted exercises. Kinematic assessment of robot assisted upper arm reaching single-joint movements.

    Science.gov (United States)

    Iuppariello, Luigi; D'Addio, Giovanni; Romano, Maria; Bifulco, Paolo; Lanzillo, Bernardo; Pappone, Nicola; Cesarelli, Mario

    2016-01-01

    Robot-mediated therapy (RMT) has been a very dynamic area of research in recent years. Robotics devices are in fact capable to quantify the performances of a rehabilitation task in treatments of several disorders of the arm and the shoulder of various central and peripheral etiology. Different systems for robot-aided neuro-rehabilitation are available for upper limb rehabilitation but the biomechanical parameters proposed until today, to evaluate the quality of the movement, are related to the specific robot used and to the type of exercise performed. Besides, none study indicated a standardized quantitative evaluation of robot assisted upper arm reaching movements, so the RMT is still far to be considered a standardised tool. In this paper a quantitative kinematic assessment of robot assisted upper arm reaching movements, considering also the effect of gravity on the quality of the movements, is proposed. We studied a group of 10 healthy subjects and results indicate that our advised protocol can be useful for characterising normal pattern in reaching movements.

  18. Analysis of Arm Movement Prediction by Using the Electroencephalography Signal

    Directory of Open Access Journals (Sweden)

    Reza Darmakusuma

    2016-04-01

    Full Text Available Various technological approaches have been developed in order to help those people who are unfortunateenough to be afflicted with different types of paralysis which limit them in performing their daily life activitiesindependently. One of the proposed technologies is the Brain-Computer Interface (BCI. The BCI system uses electroencephalography (EEG which is generated by the subject’s mental activityas input, and converts it into commands. Some previous experiments have shown the capability of the BCI system to predict the movement intention before the actual movement is onset. Thus research has predicted the movement by discriminating between data in the “rest” condition, wherethere is no movement intention, with “pre-movement” condition, where movement intention is detected before actual movement occurs. This experiment, however, was done to analyze the system for which machine learning was applied to data obtained in a continuous time interval, between 3 seconds before the movement was detected until 1 second after the actual movement was onset. This experiment shows that the system can discriminate the “pre-movement” condition and “rest” condition by using the EEG signal in 7-30 Hzwhere the Mu and Beta rhythm can be discovered with an average True Positive Rate (TPR value of 0.64 ± 0.11 and an average False Positive Rate (FPR of 0.17 ± 0.08. This experiment also shows that by using EEG signals obtained nearing the movement onset, the system has higher TPR or a detection rate in predicting the movement intention.

  19. Unified nature of bimanual movements revealed by separating the preparation of each arm.

    Science.gov (United States)

    Blinch, Jarrod; Franks, Ian M; Carpenter, Mark G; Chua, Romeo

    2015-06-01

    Movement preparation of bimanual asymmetric movements is longer than bimanual symmetric movements in choice reaction time conditions, even when movements are cued directly by illuminating the targets (Blinch et al. in Exp Brain Res 232(3):947-955, 2014). This bimanual asymmetric cost may be caused by increased processing demands on response programming, but this requires further investigation. The present experiment tested the demands on response programming for bimanual movements by temporally separating the preparation of each arm. This was achieved by precuing the target of one arm before the imperative stimulus. We asked: What was prepared in advance when one arm was precued? The answer to this question would suggest which process causes the bimanual asymmetric cost. Advance movement preparation was examined by comparing reaction times with and without a precue for the left target and by occasionally replacing the imperative stimulus with a loud, startling tone (120 dB). A startle tone releases whatever movement is prepared in advance with a much shorter reaction time than control trials (Carlsen et al. in Clin Neurophysiol 123(1):21-33, 2012). Participants made bimanual symmetric and asymmetric reaching movements in simple and 2-choice reaction time conditions and a condition with a precue for the left target. We found a bimanual asymmetric cost in 2-choice conditions, and the asymmetric cost was significantly smaller when the left target was precued. These results, and the results from startle trials, suggest (1) that the precued movement was not fully programmed but partially programmed before the imperative stimulus and (2) that the asymmetric cost was caused by increased processing demands on response programming. Overall, the results support the notion that bimanual movements are not the sum of two unimanual movements; instead, the two arms of a bimanual movement are unified into a functional unit. When one target is precued, this critical unification

  20. Integrated database for rapid mass movements in Norway

    Directory of Open Access Journals (Sweden)

    C. Jaedicke

    2009-03-01

    Full Text Available Rapid gravitational slope mass movements include all kinds of short term relocation of geological material, snow or ice. Traditionally, information about such events is collected separately in different databases covering selected geographical regions and types of movement. In Norway the terrain is susceptible to all types of rapid gravitational slope mass movements ranging from single rocks hitting roads and houses to large snow avalanches and rock slides where entire mountainsides collapse into fjords creating flood waves and endangering large areas. In addition, quick clay slides occur in desalinated marine sediments in South Eastern and Mid Norway. For the authorities and inhabitants of endangered areas, the type of threat is of minor importance and mitigation measures have to consider several types of rapid mass movements simultaneously.

    An integrated national database for all types of rapid mass movements built around individual events has been established. Only three data entries are mandatory: time, location and type of movement. The remaining optional parameters enable recording of detailed information about the terrain, materials involved and damages caused. Pictures, movies and other documentation can be uploaded into the database. A web-based graphical user interface has been developed allowing new events to be entered, as well as editing and querying for all events. An integration of the database into a GIS system is currently under development.

    Datasets from various national sources like the road authorities and the Geological Survey of Norway were imported into the database. Today, the database contains 33 000 rapid mass movement events from the last five hundred years covering the entire country. A first analysis of the data shows that the most frequent type of recorded rapid mass movement is rock slides and snow avalanches followed by debris slides in third place. Most events are recorded in the steep fjord

  1. Transversus abdominis is part of a global not local muscle synergy during arm movement.

    Science.gov (United States)

    Morris, S L; Lay, B; Allison, G T

    2013-10-01

    The trunk muscle transversus abdominis (TrA) is thought to be controlled independently of the global trunk muscles. Methodological issues in the 1990s research such as unilateral electromyography and a limited range of arm movements justify a re-examination of this theory. The hypothesis tested is that TrA bilateral co-contraction is a typical muscle synergy during arm movement. The activity of 6 pairs of trunk and lower limb muscles was recorded using bilateral electromyography during anticipatory postural adjustments (APAs) associated with the arm movements. The integrated APA electromyographical signals were analyzed for muscle synergy using Principle Component Analysis. TrA does not typically bilaterally co-contract during arm movements (1 out of 6 participants did). APA muscle activity of all muscles during asymmetrical arm movements typically reflected a direction specific diagonal pattern incorporating a twisting motion to transfer energy from the ground up. This finding is not consistent with the hypothesis that TrA plays a unique role providing bilateral, feedforward, multidirectional stiffening of the spine. This has significant implications to the theories underlying the role of TrA in back pain and in the training of isolated bilateral co-contraction of TrA in the prophylaxis of back pain. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  2. Muscle synergy extraction during arm reaching movements at different speeds.

    Science.gov (United States)

    Sabzevari, Vahid Reza; Jafari, Amir Homayoun; Boostani, Reza

    2017-01-01

    Muscle synergy is the activation of a group of muscles that contribute to a particular movement. The goal of the present study is to examine the hypothesis that human reaching movements at different speeds share similar muscle synergies and to investigate the kinesiology basis and innervation of muscles. Electromyographic activity from six muscles of the upper limb and shoulder girdle were recorded during three movements at different speeds, i.e. slow, moderate and fast. The effect of window length on the RMS signal of the EMG was analyzed and then EMG envelope signals were decomposed using non-negative matrix factorization. For each of the ten subjects, three synergies were extracted which accounted for at least 99% of the VAF. For each movement, the muscle synergies and muscle activation coefficients of all participants were clustered in to three partitions. Investigation showed a high similarity and dependency of cluster members due to the cosine similarity and mutual information in muscle synergy clustering. For further verification, the EMG envelope signals for all subjects were reconstructed. The results indicated a lower reconstruction error using the center of the muscle synergy clusters in comparison with the average of the activation coefficients, which confirms the current research's hypothesis.

  3. Octopus arm movements under constrained conditions: adaptation, modification and plasticity of motor primitives.

    Science.gov (United States)

    Richter, Jonas N; Hochner, Binyamin; Kuba, Michael J

    2015-04-01

    The motor control of the eight highly flexible arms of the common octopus (Octopus vulgaris) has been the focus of several recent studies. Our study is the first to manage to introduce a physical constraint to an octopus arm and investigate the adaptability of stereotypical bend propagation in reaching movements and the pseudo-limb articulation during fetching. Subjects (N=6) were placed inside a transparent Perspex box with a hole at the center that allowed the insertion of a single arm. Animals had to reach out through the hole toward a target, to retrieve a food reward and fetch it. All subjects successfully adjusted their movements to the constraint without an adaptation phase. During reaching tasks, the animals showed two movement strategies: stereotypical bend propagation reachings, which were established at the hole of the Perspex box and variant waving-like movements that showed no bend propagations. During fetching movements, no complete pseudo-joint fetching was observed outside the box and subjects pulled their arms through the hole in a pull-in like movement. Our findings show that there is some flexibility in the octopus motor system to adapt to a novel situation. However, at present, it seems that these changes are more an effect of random choices between different alternative motor programs, without showing clear learning effects in the choice between the alternatives. Interestingly, animals were able to adapt the fetching movements to the physical constraint, or as an alternative explanation, they could switch the motor primitive fetching to a different motor primitive 'arm pulling'. © 2015. Published by The Company of Biologists Ltd.

  4. Detecting elementary arm movements by tracking upper limb joint angles with MARG sensors

    OpenAIRE

    Mazomenos, Evangelos B.; Biswas, Dwaipayan; Cranny, Andy; Rajan, Amal; Maharatna, Koushik; Achner, Josy; Klemke, Jasmin; Jobges, Michael; Ortmann, Steffen; Langendorfer, Peter

    2015-01-01

    This paper reports an algorithm for the detection of three elementary upper limb movements, i.e., reach and retrieve, bend the arm at the elbow and rotation of the arm about the long axis. We employ two MARG sensors, attached at the elbow and wrist, from which the kinematic properties (joint angles, position) of the upper arm and forearm are calculated through data fusion using a quaternion-based gradient-descent method and a two-link model of the upper limb. By studying the kinematic pattern...

  5. Learning course adjustments during arm movements with reversed sensitivity derivatives

    Directory of Open Access Journals (Sweden)

    Tweed Douglas B

    2010-11-01

    Full Text Available Abstract Background To learn, a motor system needs to know its sensitivity derivatives, which quantify how its neural commands affect motor error. But are these derivatives themselves learned, or are they known solely innately? Here we test a recent theory that the brain's estimates of sensitivity derivatives are revisable based on sensory feedback. In its simplest form, the theory says that each control system has a single, adjustable estimate of its sensitivity derivatives which affects all aspects of its task, e.g. if you learn to reach to mirror-reversed targets then your revised estimate should reverse not only your initial aiming but also your online course adjustments when the target jumps in mid-movement. Methods Human subjects bent a joystick to move a cursor to a target on a computer screen, but the cursor's motion was reversed relative to the joystick's. The target jumped once during each movement. Subjects had up to 4000 trials to practice aiming and responding to target jumps. Results All subjects learned to reverse both initial aiming and course adjustments. Conclusions Our study confirms that sensitivity derivatives can be relearned. It is consistent with the idea of a single, all-purpose estimate of those derivatives; and it suggests that the estimate is a function of context, as one would expect given that the true sensitivity derivatives may vary with the state of the controlled system, the target, and the motor commands.

  6. Effective propulsion in swimming: grasping the hydrodynamics of hand and arm movements

    NARCIS (Netherlands)

    van Houwelingen, J.; Schreven, S.; Smeets, J.J.B.; Clercx, H.J.H.; Beek, P.J.

    2017-01-01

    A literature review is presented about the hydrodynamic effects of different hand and arm movements during swimming with the aim to identify lacunae in current methods and knowledge, and to distil practical guidelines for coaches and swimmers seeking to increase swimming speed. Experimental and

  7. Octopuses use a human-like strategy to control precise point-to-point arm movements.

    Science.gov (United States)

    Sumbre, Germán; Fiorito, Graziano; Flash, Tamar; Hochner, Binyamin

    2006-04-18

    One of the key problems in motor control is mastering or reducing the number of degrees of freedom (DOFs) through coordination. This problem is especially prominent with hyper-redundant limbs such as the extremely flexible arm of the octopus. Several strategies for simplifying these control problems have been suggested for human point-to-point arm movements. Despite the evolutionary gap and morphological differences, humans and octopuses evolved similar strategies when fetching food to the mouth. To achieve this precise point-to-point-task, octopus arms generate a quasi-articulated structure based on three dynamic joints. A rotational movement around these joints brings the object to the mouth . Here, we describe a peripheral neural mechanism-two waves of muscle activation propagate toward each other, and their collision point sets the medial-joint location. This is a remarkably simple mechanism for adjusting the length of the segments according to where the object is grasped. Furthermore, similar to certain human arm movements, kinematic invariants were observed at the joint level rather than at the end-effector level, suggesting intrinsic control coordination. The evolutionary convergence to similar geometrical and kinematic features suggests that a kinematically constrained articulated limb controlled at the level of joint space is the optimal solution for precise point-to-point movements.

  8. Automation of angular movement of the arm neutron diffractometer

    International Nuclear Information System (INIS)

    Aguilar H, F.; Herrera A, E.; Quintana C, G.; Torres R, C. E.; Reyes V, M.

    2015-09-01

    A technique to determine the crystal structure of some materials is the neutron diffraction. This technique consists on placing the material in question in a monoenergetic neutron beam obtained by neutron diffraction in a monochromator crystal. The neutron energy depends of the diffraction angle. The Instituto Nacional de Investigaciones Nucleares has a neutron diffractometer and monochromator crystals of pyrolytic graphite. This crystal can be selecting the neutron energy depending on the angle of diffraction in the glass. The radiation source for the neutron diffractometer is the TRIGA Mark III reactor of the Nuclear Center Dr. Nabor Carrillo Flores. During their operation are also obtained besides neutrons, β and γ radiation. The interest is to have thermal neutrons, so fast neutrons and γ rays are removed using appropriate shielding. The average neutron fluxes of the radial port RE2 of neutron diffractometer at power 1 MW are: heat flow 2,466 x 10 8 n cm -2 sec -1 and fast flow 1,239 x 10 8 n cm -2 sec -1 . The neutron detector is housed in a shield mounted on a mechanical linkage with which the diffraction angle is selected, and therefore the energy of the neutrons. The movement of this joint was performed by the equipment operator manually, so that accuracy to select the diffraction angle was not good and the process rather slow. Therefore a mechanical system was designed, automated by means of a motor as an actuator, a system of force transmission and an electronic control in order that the operator will schedule the diffraction angles and allow the count in the neutrons detection system in a simple manner. (Author)

  9. Rapid eye movement sleep disturbances in Huntington disease

    DEFF Research Database (Denmark)

    Arnulf, I.; Nielsen, J.; Lohmann, E.

    2008-01-01

    and shortened rapid eye movement (REM) sleep, and increased periodic leg movements. Three HD patients (12%) had REM sleep behavior disorders. No sleep abnormality correlated with CAG repeat length. Reduced REM sleep duration (but not REM sleep behavior disorders) was present in premanifest carriers and patients...... with very mild HD and worsened with disease severity. In contrast to narcoleptic patients, HD patients had no cataplexy, hypnagogic hallucinations, or sleep paralysis. Four HD patients had abnormally low (sleep latencies, but none had multiple sleep-onset REM periods. Conclusions......: The sleep phenotype of HD includes insomnia, advanced sleep phase, periodic leg movements, REM sleep behavior disorders, and reduced REM sleep but not narcolepsy. Reduced REM sleep may precede chorea. Mutant huntingtin may exert an effect on REM sleep and motor control during sleep Udgivelsesdato: 2008/4...

  10. Detecting rapid mass movements using electrical self-potential measurements

    Science.gov (United States)

    Heinze, Thomas; Limbrock, Jonas; Pudasaini, Shiva P.; Kemna, Andreas

    2017-04-01

    Rapid mass movements are a latent danger for lives and infrastructure in almost any part of the world. Often such mass movements are caused by increasing pore pressure, for example, landslides after heavy rainfall or dam breaking after intrusion of water in the dam. Among several other geophysical methods used to observe water movement, the electrical self-potential method has been applied to a broad range of monitoring studies, especially focusing on volcanism and dam leakage but also during hydraulic fracturing and for earthquake prediction. Electrical self-potential signals may be caused by various mechanisms. Though, the most relevant source of the self-potential field in the given context is the streaming potential, caused by a flowing electrolyte through porous media with electrically charged internal surfaces. So far, existing models focus on monitoring water flow in non-deformable porous media. However, as the self-potential is sensitive to hydraulic parameters of the soil, any change in these parameters will cause an alteration of the electric signal. Mass movement will significantly influence the hydraulic parameters of the solid as well as the pressure field, assuming that fluid movement is faster than the pressure diffusion. We will present results of laboratory experiments under drained and undrained conditions with fluid triggered as well as manually triggered mass movements, monitored with self-potential measurements. For the undrained scenarios, we observe a clear correlation between the mass movements and signals in the electric potential, which clearly differ from the underlying potential variations due to increased saturation and fluid flow. In the drained experiments, we do not observe any measurable change in the electric potential. We therefore assume that change in fluid properties and release of the load causes disturbances in flow and streaming potential. We will discuss results of numerical simulations reproducing the observed effect. Our

  11. Morbidities in rapid eye movement sleep behavior disorder

    DEFF Research Database (Denmark)

    Jennum, Poul; Mayer, Geert; Ju, Yo-El

    2013-01-01

    Idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD, RBD without any obvious comorbid major neurological disease), is strongly associated with numerous comorbid conditions. The most prominent is that with neurodegenerative disorders, especially synuclein-mediated disorders, above all...... function, neuropsychiatric manifestations and sleep complaints. Furthermore, patients with PD and RBD may have worse prognosis in terms of impaired cognitive function and overall morbidity/mortality; in dementia, the presence of RBD is strongly associated with clinical hallmarks and pathological findings...

  12. Sonification of Arm Movements in Stroke Rehabilitation – A Novel Approach in Neurologic Music Therapy

    Science.gov (United States)

    Scholz, Daniel S.; Rohde, Sönke; Nikmaram, Nikou; Brückner, Hans-Peter; Großbach, Michael; Rollnik, Jens D.; Altenmüller, Eckart O.

    2016-01-01

    Gross motor impairments are common after stroke, but efficient and motivating therapies for these impairments are scarce. We present an innovative musical sonification therapy, especially designed to retrain patients’ gross motor functions. Sonification should motivate patients and provide additional sensory input informing about relative limb position. Twenty-five stroke patients were included in a clinical pre–post study and took part in the sonification training. The patients’ upper extremity functions, their psychological states, and their arm movement smoothness were assessed pre and post training. Patients were randomly assigned to either of two groups. Both groups received an average of 10 days (M = 9.88; SD = 2.03; 30 min/day) of musical sonification therapy [music group (MG)] or a sham sonification movement training [control group (CG)], respectively. The only difference between the two protocols was that in the CG no sound was played back during training. In the beginning, patients explored the acoustic effects of their arm movements in space. At the end of the training, the patients played simple melodies by coordinated arm movements. The 15 patients in the MG showed significantly reduced joint pain (F = 19.96, p therapy. Taken together, musical sonification may be a promising therapy for motor impairments after stroke, but further research is required since estimated effect sizes point to moderate treatment outcomes. PMID:27445970

  13. Sonification of Arm Movements in Stroke Rehabilitation - A Novel Approach in Neurologic Music Therapy.

    Science.gov (United States)

    Scholz, Daniel S; Rohde, Sönke; Nikmaram, Nikou; Brückner, Hans-Peter; Großbach, Michael; Rollnik, Jens D; Altenmüller, Eckart O

    2016-01-01

    Gross motor impairments are common after stroke, but efficient and motivating therapies for these impairments are scarce. We present an innovative musical sonification therapy, especially designed to retrain patients' gross motor functions. Sonification should motivate patients and provide additional sensory input informing about relative limb position. Twenty-five stroke patients were included in a clinical pre-post study and took part in the sonification training. The patients' upper extremity functions, their psychological states, and their arm movement smoothness were assessed pre and post training. Patients were randomly assigned to either of two groups. Both groups received an average of 10 days (M = 9.88; SD = 2.03; 30 min/day) of musical sonification therapy [music group (MG)] or a sham sonification movement training [control group (CG)], respectively. The only difference between the two protocols was that in the CG no sound was played back during training. In the beginning, patients explored the acoustic effects of their arm movements in space. At the end of the training, the patients played simple melodies by coordinated arm movements. The 15 patients in the MG showed significantly reduced joint pain (F = 19.96, p musical sonification may be a promising therapy for motor impairments after stroke, but further research is required since estimated effect sizes point to moderate treatment outcomes.

  14. A flow visualization study of single-arm sculling movement emulating cephalopod thrust generation

    Science.gov (United States)

    Kazakidi, Asimina; Gnanamanickam, Ebenezer P.; Tsakiris, Dimitris P.; Ekaterinaris, John A.

    2014-11-01

    In addition to jet propulsion, octopuses use arm-swimming motion as an effective means of generating bursts of thrust, for hunting, defense, or escape. The individual role of their arms, acting as thrust generators during this motion, is still under investigation, in view of an increasing robotic interest for alternative modes of propulsion, inspired by the octopus. Computational studies have revealed that thrust generation is associated with complex vortical flow patterns in the wake of the moving arm, however further experimental validation is required. Using the hydrogen bubble technique, we studied the flow disturbance around a single octopus-like robotic arm, undergoing two-stroke sculling movements in quiescent fluid. Although simplified, sculling profiles have been found to adequately capture the fundamental kinematics of the octopus arm-swimming behavior. In fact, variation of the sculling parameters alters considerably the generation of forward thrust. Flow visualization revealed the generation of complex vortical structures around both rigid and compliant arms. Increased disturbance was evident near the tip, particularly at the transitional phase between recovery and power strokes. These results are in good qualitative agreement with computational and robotic studies. Work funded by the ESF-GSRT HYDRO-ROB Project PE7(281).

  15. Compensation for loads during arm movements using equilibrium-point control.

    Science.gov (United States)

    Gribble, P L; Ostry, D J

    2000-12-01

    A significant problem in motor control is how information about movement error is used to modify control signals to achieve desired performance. A potential source of movement error and one that is readily controllable experimentally relates to limb dynamics and associated movement-dependent loads. In this paper, we have used a position control model to examine changes to control signals for arm movements in the context of movement-dependent loads. In the model, based on the equilibrium-point hypothesis, equilibrium shifts are adjusted directly in proportion to the positional error between desired and actual movements. The model is used to simulate multi-joint movements in the presence of both "internal" loads due to joint interaction torques, and externally applied loads resulting from velocity-dependent force fields. In both cases it is shown that the model can achieve close correspondence to empirical data using a simple linear adaptation procedure. An important feature of the model is that it achieves compensation for loads during movement without the need for either coordinate transformations between positional error and associated corrective forces, or inverse dynamics calculations.

  16. Updating visual memory across eye movements for ocular and arm motor control.

    Science.gov (United States)

    Thompson, Aidan A; Henriques, Denise Y P

    2008-11-01

    Remembered object locations are stored in an eye-fixed reference frame, so that every time the eyes move, spatial representations must be updated for the arm-motor system to reflect the target's new relative position. To date, studies have not investigated how the brain updates these spatial representations during other types of eye movements, such as smooth-pursuit. Further, it is unclear what information is used in spatial updating. To address these questions we investigated whether remembered locations of pointing targets are updated following smooth-pursuit eye movements, as they are following saccades, and also investigated the role of visual information in estimating eye-movement amplitude for updating spatial memory. Misestimates of eye-movement amplitude were induced when participants visually tracked stimuli presented with a background that moved in either the same or opposite direction of the eye before pointing or looking back to the remembered target location. We found that gaze-dependent pointing errors were similar following saccades and smooth-pursuit and that incongruent background motion did result in a misestimate of eye-movement amplitude. However, the background motion had no effect on spatial updating for pointing, but did when subjects made a return saccade, suggesting that the oculomotor and arm-motor systems may rely on different sources of information for spatial updating.

  17. Strategy of arm movement control is determined by minimization of neural effort for joint coordination.

    Science.gov (United States)

    Dounskaia, Natalia; Shimansky, Yury

    2016-06-01

    Optimality criteria underlying organization of arm movements are often validated by testing their ability to adequately predict hand trajectories. However, kinematic redundancy of the arm allows production of the same hand trajectory through different joint coordination patterns. We therefore consider movement optimality at the level of joint coordination patterns. A review of studies of multi-joint movement control suggests that a 'trailing' pattern of joint control is consistently observed during which a single ('leading') joint is rotated actively and interaction torque produced by this joint is the primary contributor to the motion of the other ('trailing') joints. A tendency to use the trailing pattern whenever the kinematic redundancy is sufficient and increased utilization of this pattern during skillful movements suggests optimality of the trailing pattern. The goal of this study is to determine the cost function minimization of which predicts the trailing pattern. We show that extensive experimental testing of many known cost functions cannot successfully explain optimality of the trailing pattern. We therefore propose a novel cost function that represents neural effort for joint coordination. That effort is quantified as the cost of neural information processing required for joint coordination. We show that a tendency to reduce this 'neurocomputational' cost predicts the trailing pattern and that the theoretically developed predictions fully agree with the experimental findings on control of multi-joint movements. Implications for future research of the suggested interpretation of the trailing joint control pattern and the theory of joint coordination underlying it are discussed.

  18. Interactive Design and Development of Real Arm Movements for Application in Rehabilitation

    Science.gov (United States)

    Rosman, Rafidah; Hadi, Muhammad Zaidan Abdul; Abu Bakar, Nurulliyana

    2018-03-01

    An interactive real arm movements for application in rehabilitation is designed and developed. The aim is to encourage hand paralysis patients performing their physical therapy by introducing games application in replacing conventional hand therapy module and methods. In this project, the accelerometer is used for tracking the orientation of the arm. As the arm moves, the values from x, y and z axis from the accelerometer changes and are being read by the Analog Inputs of the Arduino Board. After being read by the Analog Inputs of the Arduino Board, the 3D model moves as well. Solidworks software was used to modeled the hand in which the data is then transferred to Matlab/Simulink using SimMechanicalLink from Mathworks. Lastly, the sensor glove was programmed to work as a controller of games application in hand rehabilitation thus makes it an enjoyable therapy process.

  19. Validation Studies of the Human Movement Analysis Panel for Hand/Arm Performance

    OpenAIRE

    Smith, Charles D.; Walton, Ashley; Slevin, John T.; Gerhardt, Greg A.; Umberger, Gloria; Smoot, Kyle; Schulze, Emily; Gash, Don

    2007-01-01

    The human movement analysis panel (HMAP) measures separable components of arm motion and simple and complex finger coordination. HMAP testing takes 30 minutes to administer. In separate experiments we have validated the HMAP against the standard grooved pegboard and measures of gait speed, and demonstrated important learning effects over both short durations of days, and longer intervals of months to years in normal subjects of different ages. Stepwise regression demonstrated the strongest co...

  20. A Biomechanical Model of Single-joint Arm Movement Control Based on the Equilibrium Point Hypothesis

    OpenAIRE

    Masataka, SUZUKI; Yoshihiko, YAMAZAKI; Yumiko, TANIGUCHI; Department of Psychology, Kinjo Gakuin University; Department of Health and Physical Education, Nagoya Institute of Technology; College of Human Life and Environment, Kinjo Gakuin University

    2003-01-01

    SUZUKI,M., YAMAZAKI,Y. and TANIGUCHI,Y., A Biomechanical Model of Single-joint Arm Movement Control Based on the Equilibrium Point Hypothesis. Adv. Exerc. Sports Physiol., Vol.9, No.1 pp.7-25, 2003. According to the equilibrium point hypothesis of motor control, control action of muscles is not explicitly computed, but rather arises as a consequence of interaction among moving equilibrium point, reflex feedback and muscle mechanical properties. This approach is attractive as it obviates the n...

  1. Characteristics of rapid eye movement sleep behavior disorder in narcolepsy

    DEFF Research Database (Denmark)

    Jennum, Poul Jørgen; Frandsen, Rune Asger Vestergaard; Knudsen, Stine

    2013-01-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by dream-enacting behavior and impaired motor inhibition during REM sleep (REM sleep without atonia, RSWA). RBD is commonly associated with Parkinsonian disorders, but is also reported in narcolepsy. Most patients...... of hypocretin deficiency. Thus, hypocretin deficiency is linked to the two major disturbances of REM sleep motor regulation in narcolepsy: RBD and cataplexy. Moreover, it is likely that hypocretin deficiency independently predicts periodic limb movements in REM and NREM sleep, probably via involvement...... of the dopaminergic system. This supports the hypothesis that an impaired hypocretin system causes general instability of motor regulation during wakefulness, REM and NREM sleep in human narcolepsy. We propose that hypocretin neurons are centrally involved in motor tone control during wakefulness and sleep in humans...

  2. The role of vision, speed, and attention in overcoming directional biases during arm movements.

    Science.gov (United States)

    Dounskaia, Natalia; Goble, Jacob A

    2011-03-01

    Previous research has revealed directional biases (preferences to select movements in specific directions) during horizontal arm movements with the use of a free-stroke drawing task. The biases were interpreted as a result of a tendency to generate motion at either the shoulder or elbow (leading joint) and move the other (subordinate) joint predominantly passively to avoid neural effort for control of interaction torque. Here, we examined influence of vision, movement speed, and attention on the directional biases. Participants performed the free-stroke drawing task, producing center-out strokes in randomly selected directions. Movements were performed with and without vision and at comfortable and fast pace. A secondary, cognitive task was used to distract attention. Preferred directions remained the same in all conditions. Bias strength mildly increased without vision, especially during fast movements. Striking increases in bias strength were caused by the secondary task, pointing to additional cognitive load associated with selection of movements in the non-preferred directions. Further analyses demonstrated that the tendency to minimize active interference with interaction torque at the subordinate joint matched directional biases in all conditions. This match supports the explanation of directional biases as a result of a tendency to minimize neural effort for interaction torque control. The cognitive load may enhance this tendency in two ways, directly, by reducing neural capacity for interaction torque control, and indirectly, by decreasing capacity of working memory that stores visited directions. The obtained results suggest strong directional biases during daily activities because natural arm movements usually subserve cognitive tasks.

  3. Fluid Mixing in the Eye Under Rapid Eye Movement

    Science.gov (United States)

    Huang, Jinglin; Gharib, Morteza

    2017-11-01

    Drug injection is an important technique in certain treatments of eye diseases. The efficacy of chemical mixing plays an important role in determining pharmacokinetics of injected drugs. In this study, we build a device to study the chemical mixing behavior in a spherical structure. The mixing process is visualized and analyzed qualitatively. We hope to understand the chemical convection and diffusion behaviors in correlation with controlled rapid mechanical movements. The results will have potential applications in treatment of eye diseases. Resnick Institute at Caltech.

  4. Sensorimotor Reorganizations of Arm Kinematics and Postural Strategy for Functional Whole-Body Reaching Movements in Microgravity

    Directory of Open Access Journals (Sweden)

    Thomas Macaluso

    2017-10-01

    Full Text Available Understanding the impact of weightlessness on human behavior during the forthcoming long-term space missions is of critical importance, especially when considering the efficiency of goal-directed movements in these unusual environments. Several studies provided a large set of evidence that gravity is taken into account during the planning stage of arm reaching movements to optimally anticipate its consequence upon the moving limbs. However, less is known about sensorimotor changes required to face weightless environments when individuals have to perform fast and accurate goal-directed actions with whole-body displacement. We thus aimed at characterizing kinematic features of whole-body reaching movements in microgravity, involving high spatiotemporal constraints of execution, to question whether and how humans are able to maintain the performance of a functional behavior in the standards of normogravity execution. Seven participants were asked to reach as fast and as accurately as possible visual targets while standing during microgravity episodes in parabolic flight. Small and large targets were presented either close or far from the participants (requiring, in the latter case, additional whole-body displacement. Results reported that participants successfully performed the reaching task with general temporal features of movement (e.g., movement speed close to land observations. However, our analyses also demonstrated substantial kinematic changes related to the temporal structure of focal movement and the postural strategy to successfully perform -constrained- whole-body reaching movements in microgravity. These immediate reorganizations are likely achieved by rapidly taking into account the absence of gravity in motor preparation and execution (presumably from cues about body limbs unweighting. Specifically, when compared to normogravity, the arm deceleration phase substantially increased. Furthermore, greater whole-body forward displacements

  5. The improvement of movement and speech during rapid eye movement sleep behaviour disorder in multiple system atrophy.

    Science.gov (United States)

    De Cock, Valérie Cochen; Debs, Rachel; Oudiette, Delphine; Leu, Smaranda; Radji, Fatai; Tiberge, Michel; Yu, Huan; Bayard, Sophie; Roze, Emmanuel; Vidailhet, Marie; Dauvilliers, Yves; Rascol, Olivier; Arnulf, Isabelle

    2011-03-01

    Multiple system atrophy is an atypical parkinsonism characterized by severe motor disabilities that are poorly levodopa responsive. Most patients develop rapid eye movement sleep behaviour disorder. Because parkinsonism is absent during rapid eye movement sleep behaviour disorder in patients with Parkinson's disease, we studied the movements of patients with multiple system atrophy during rapid eye movement sleep. Forty-nine non-demented patients with multiple system atrophy and 49 patients with idiopathic Parkinson's disease were interviewed along with their 98 bed partners using a structured questionnaire. They rated the quality of movements, vocal and facial expressions during rapid eye movement sleep behaviour disorder as better than, equal to or worse than the same activities in an awake state. Sleep and movements were monitored using video-polysomnography in 22/49 patients with multiple system atrophy and in 19/49 patients with Parkinson's disease. These recordings were analysed for the presence of parkinsonism and cerebellar syndrome during rapid eye movement sleep movements. Clinical rapid eye movement sleep behaviour disorder was observed in 43/49 (88%) patients with multiple system atrophy. Reports from the 31/43 bed partners who were able to evaluate movements during sleep indicate that 81% of the patients showed some form of improvement during rapid eye movement sleep behaviour disorder. These included improved movement (73% of patients: faster, 67%; stronger, 52%; and smoother, 26%), improved speech (59% of patients: louder, 55%; more intelligible, 17%; and better articulated, 36%) and normalized facial expression (50% of patients). The rate of improvement was higher in Parkinson's disease than in multiple system atrophy, but no further difference was observed between the two forms of multiple system atrophy (predominant parkinsonism versus cerebellar syndrome). Video-monitored movements during rapid eye movement sleep in patients with multiple system

  6. Context-dependent adaptation of visually-guided arm movements and vestibular eye movements: role of the cerebellum

    Science.gov (United States)

    Lewis, Richard F.

    2003-01-01

    Accurate motor control requires adaptive processes that correct for gradual and rapid perturbations in the properties of the controlled object. The ability to quickly switch between different movement synergies using sensory cues, referred to as context-dependent adaptation, is a subject of considerable interest at present. The potential function of the cerebellum in context-dependent adaptation remains uncertain, but the data reviewed below suggest that it may play a fundamental role in this process.

  7. Soft Neurological Signs in Childhood by Measurement of Arm Movements Using Acceleration and Angular Velocity Sensors

    Directory of Open Access Journals (Sweden)

    Miki Kaneko

    2015-10-01

    Full Text Available Soft neurological signs (SNS are evident in the motor performance of children and disappear as the child grows up. Therefore SNS are used as criteria for evaluating age-appropriate development of neurological function. The aim of this study was to quantify SNS during arm movement in childhood. In this study, we focused on pronation and supination, which are arm movements included in the SNS examination. Two hundred and twenty-three typically developing children aged 4–12 years (107 boys, 116 girls and 18 adults aged 21–26 years (16 males, two females participated in the experiment. To quantify SNS during pronation and supination, we calculated several evaluation index scores: bimanual symmetry, compliance, postural stability, motor speed and mirror movement. These index scores were evaluated using data obtained from sensors attached to the participants’ hands and elbows. Each score increased as age increased. Results obtained using our system showed developmental changes that were consistent with criteria for SNS. We were able to successfully quantify SNS during pronation and supination. These results indicate that it may be possible to use our system as quantitative criteria for evaluating development of neurological function.

  8. Soft neurological signs in childhood by measurement of arm movements using acceleration and angular velocity sensors.

    Science.gov (United States)

    Kaneko, Miki; Yamashita, Yushiro; Inomoto, Osamu; Iramina, Keiji

    2015-10-12

    Soft neurological signs (SNS) are evident in the motor performance of children and disappear as the child grows up. Therefore SNS are used as criteria for evaluating age-appropriate development of neurological function. The aim of this study was to quantify SNS during arm movement in childhood. In this study, we focused on pronation and supination, which are arm movements included in the SNS examination. Two hundred and twenty-three typically developing children aged 4-12 years (107 boys, 116 girls) and 18 adults aged 21-26 years (16 males, two females) participated in the experiment. To quantify SNS during pronation and supination, we calculated several evaluation index scores: bimanual symmetry, compliance, postural stability, motor speed and mirror movement. These index scores were evaluated using data obtained from sensors attached to the participants' hands and elbows. Each score increased as age increased. Results obtained using our system showed developmental changes that were consistent with criteria for SNS. We were able to successfully quantify SNS during pronation and supination. These results indicate that it may be possible to use our system as quantitative criteria for evaluating development of neurological function.

  9. Tactile information processing in primate hand somatosensory cortex (S1) during passive arm movement.

    Science.gov (United States)

    Song, Weiguo; Francis, Joseph Thachil

    2013-11-01

    Motor output mostly depends on sensory input, which also can be affected by action. To further our understanding of how tactile information is processed in the primary somatosensory cortex (S1) in dynamic environments, we recorded neural responses to tactile stimulation of the hand in three awake monkeys under arm/hand passive movement and rest. We found that neurons generally responded to tactile stimulation under both conditions and were modulated by movement: with a higher baseline firing rate, a suppressed peak rate, and a smaller dynamic range during passive movement than during rest, while the area under the response curve was stable across these two states. By using an information theory-based method, the mutual information between tactile stimulation and neural responses was quantified with rate and spatial coding models under the two conditions. The two potential encoding models showed different contributions depending on behavioral contexts. Tactile information encoded with rate coding from individual units was lower than spatial coding of unit pairs, especially during movement; however, spatial coding had redundant information between unit pairs. Passive movement regulated the mutual information, and such regulation might play different roles depending on the encoding strategies used. The underlying mechanisms of our observation most likely come from a bottom-up strategy, where neurons in S1 were regulated through the activation of the peripheral tactile/proprioceptive receptors and the interactions between these different types of information.

  10. Rapid eye movement sleep behaviour disorder in patients with narcolepsy is associated with hypocretin-1 deficiency

    DEFF Research Database (Denmark)

    Knudsen, Stine; Gammeltoft, Steen; Jennum, Poul J

    2010-01-01

    Rapid eye movement sleep behaviour disorder is characterized by dream-enacting behaviour and impaired motor inhibition during rapid eye movement sleep. Rapid eye movement sleep behaviour disorder is commonly associated with neurodegenerative disorders, but also reported in narcolepsy with cataplexy....... Most narcolepsy with cataplexy patients lack the sleep-wake, and rapid eye movement sleep, motor-regulating hypocretin neurons in the lateral hypothalamus. In contrast, rapid eye movement sleep behaviour disorder and hypocretin deficiency are rare in narcolepsy without cataplexy. We hypothesized...... that rapid eye movement sleep behaviour disorder coexists with cataplexy in narcolepsy due to hypocretin deficiency. In our study, rapid eye movement sleep behaviour disorder was diagnosed by the International Classification of Sleep Disorders (2nd edition) criteria in 63 narcolepsy patients with or without...

  11. [Parkinson Disease With Rapid Eye Movement Sleep Behavior Disorder].

    Science.gov (United States)

    Hu, Yang; Zhang, Wei

    2015-06-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by lack of muscle atonia during REM sleep and enactment of dream content. RBD is associated with Parkinson disease (PD) and has high incidence in PD patients. PD patient with RBD mainly presents rigid type, has longer disease duration, more severe motor and non-motor symptoms and poorer activity of daily living and life quality. The pathophysiological mechanisms of RBD may be related to dysfunctions of pontine tegmentum, locus coeruleus/sub-locus coeruleus complex and related projections. The diagnosis of RBD depends on clinical histories and video-polysomnography (v-PSG). Besides treatment for PD, protective measures have to be taken for patients and their sleep partners. If abnormal behaviors during sleep cause distress and danger,patients should be given drug therapy.

  12. Neurophysiological basis of rapid eye movement sleep behavior disorder

    DEFF Research Database (Denmark)

    Jennum, Poul; Christensen, Julie Anja Engelhard; Zoetmulder, Marielle

    2016-01-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by a history of recurrent nocturnal dream enactment behavior and loss of skeletal muscle atonia and increased phasic muscle activity during REM sleep: REM sleep without atonia. RBD and associated comorbidities have...... recently been identified as one of the most specific and potentially sensitive risk factors for later development of any of the alpha-synucleinopathies: Parkinson's disease, dementia with Lewy bodies, and other atypical parkinsonian syndromes. Several other sleep-related abnormalities have recently been...... identified in patients with RBD/Parkinson's disease who experience abnormalities in sleep electroencephalographic frequencies, sleep-wake transitions, wake and sleep stability, occurrence and morphology of sleep spindles, and electrooculography measures. These findings suggest a gradual involvement...

  13. Unloading arm movement modeling using neural networks for a rotary hearth furnace

    Directory of Open Access Journals (Sweden)

    Iulia Inoan

    2011-12-01

    Full Text Available Neural networks are being applied in many fields of engineering having nowadays a wide range of application. Neural networks are very useful for modeling dynamic processes for which the mathematical modeling is hard to obtain, or for processes that can’t be modeled using mathematical equations. This paper describes the modeling process for the unloading arm movement from a rotary hearth furnace using neural networks with back propagation algorithm. In this case the designed network was trained using the simulation results from a previous calculated mathematical model.

  14. MOVEMENT SIMULATION OF THREE ARMED ROBOT BY BEING USED AutoLISP

    Directory of Open Access Journals (Sweden)

    Mustafa BOZDEMİR

    2000-01-01

    Full Text Available Development of a suitable robot for desired aim and duty is very important for design enginers. On the other hand, designed robots may be unsuccesful in functioning inspite of many efforts. For this reason, before the production of considered robot systems, having prepared a simulation program, investigation of work field, getting done path plan and mistakes could be eliminated before robot production. In this study, movement simulation of a three armed robot has been realized by using AutoLIPS programing language which is supplied with AutoCAD. Analytical and matrix solution methods have been used in simulation equations.

  15. Movement - uncontrolled or slow

    Science.gov (United States)

    Dystonia; Involuntary slow and twisting movements; Choreoathetosis; Leg and arm movements - uncontrollable; Arm and leg movements - uncontrollable; Slow involuntary movements of large muscle groups; Athetoid movements

  16. Equilibrium-point control hypothesis examined by measured arm stiffness during multijoint movement.

    Science.gov (United States)

    Gomi, H; Kawato

    1996-04-05

    For the last 20 years, it has been hypothesized that well-coordinated, multijoint movements are executed without complex computation by the brain, with the use of springlike muscle properties and peripheral neural feedback loops. However, it has been technically and conceptually difficult to examine this "equilibrium-point control" hypothesis directly in physiological or behavioral experiments. A high-performance manipulandum was developed and used here to measure human arm stiffness, the magnitude of which during multijoint movement is important for this hypothesis. Here, the equilibrium-point trajectory was estimated from the measured stiffness, the actual trajectory, and the generated torque. Its velocity profile differed from that of the actual trajectory. These results argue against the hypothesis that the brain sends as a motor command only an equilibrium-point trajectory similar to the actual trajectory.

  17. Active Bio-sensor System, Compatible with Arm Muscle Movement or Blinking Signals in BCI Application

    Directory of Open Access Journals (Sweden)

    Saeid Mehrkanoon

    2008-05-01

    Full Text Available This paper addresses a bionic active sensor system for the BCI application. Proposed system involves analog and digital parts. Two types of accurate sensors are used to pickup the blinking and muscle movement signals. A precision micro-power instrumentation amplifier with the adjustable gain, a sixth order low pass active filter with cutoff frequency 0.1 Hz, and a sixth order band pas filter with the bandwidth of 2-6 Hz are constructed to provide the clean blinking and arm muscle movement signals. TMS320C25 DSP processor is used for independent and unique command signals which are prepared for BCI application by a power amplifier and driver.

  18. Combined Influence of Visual Scene and Body Tilt on Arm Pointing Movements: Gravity Matters!

    Science.gov (United States)

    Scotto Di Cesare, Cécile; Sarlegna, Fabrice R.; Bourdin, Christophe; Mestre, Daniel R.; Bringoux, Lionel

    2014-01-01

    Performing accurate actions such as goal-directed arm movements requires taking into account visual and body orientation cues to localize the target in space and produce appropriate reaching motor commands. We experimentally tilted the body and/or the visual scene to investigate how visual and body orientation cues are combined for the control of unseen arm movements. Subjects were asked to point toward a visual target using an upward movement during slow body and/or visual scene tilts. When the scene was tilted, final pointing errors varied as a function of the direction of the scene tilt (forward or backward). Actual forward body tilt resulted in systematic target undershoots, suggesting that the brain may have overcompensated for the biomechanical movement facilitation arising from body tilt. Combined body and visual scene tilts also affected final pointing errors according to the orientation of the visual scene. The data were further analysed using either a body-centered or a gravity-centered reference frame to encode visual scene orientation with simple additive models (i.e., ‘combined’ tilts equal to the sum of ‘single’ tilts). We found that the body-centered model could account only for some of the data regarding kinematic parameters and final errors. In contrast, the gravity-centered modeling in which the body and visual scene orientations were referred to vertical could explain all of these data. Therefore, our findings suggest that the brain uses gravity, thanks to its invariant properties, as a reference for the combination of visual and non-visual cues. PMID:24925371

  19. Investigating rapid eye movement sleep without atonia in Parkinson's disease using the rapid eye movement sleep behavior disorder screening questionnaire.

    Science.gov (United States)

    Bolitho, Samuel J; Naismith, Sharon L; Terpening, Zoe; Grunstein, Ron R; Melehan, Kerri; Yee, Brendon J; Coeytaux, Alessandra; Gilat, Moran; Lewis, Simon J G

    2014-05-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is frequently observed in patients with Parkinson's disease (PD). Accurate diagnosis is essential for managing this condition. Furthermore, the emergence of idiopathic RBD in later life can represent a premotor feature, heralding the development of PD. Reliable, accurate methods for identifying RBD may offer a window for early intervention. This study sought to identify whether the RBD screening questionnaire (RBDSQ) and three questionnaires focused on dream enactment were able to correctly identify patients with REM without atonia (RWA), the neurophysiological hallmark of RBD. Forty-six patients with PD underwent neurological and sleep assessment in addition to completing the RBDSQ, the RBD single question (RBD1Q), and the Mayo Sleep Questionnaire (MSQ). The REM atonia index was derived for all participants as an objective measure of RWA. Patients identified to be RBD positive on the RBDSQ did not show increased RWA on polysomnography (80% sensitivity and 55% specificity). However, patients positive for RBD on questionnaires specific to dream enactment correctly identified higher degrees of RWA and improved the diagnostic accuracy of these questionnaires. This study suggests that the RBDSQ does not accurately identify RWA, essential for diagnosing RBD in PD. Furthermore, the results suggest that self-report measures of RBD need to focus questions on dream enactment behavior to better identify RWA and RBD. Further studies are needed to develop accurate determination and quantification of RWA in RBD to improve management of patients with PD in the future. © 2014 International Parkinson and Movement Disorder Society.

  20. Training of goal directed arm movements with motion interactive video games in children with cerebral palsy - a kinematic evaluation.

    Science.gov (United States)

    Sandlund, Marlene; Domellöf, Erik; Grip, Helena; Rönnqvist, Louise; Häger, Charlotte K

    2014-10-01

    The main aim of this study was to evaluate the quality of goal-directed arm movements in 15 children with cerebral palsy (CP) following four weeks of home-based training with motion interactive video games. A further aim was to investigate the applicability and characteristics of kinematic parameters in a virtual context in comparison to a physical context. Kinematics and kinetics were captured while the children performed arm movements directed towards both virtual and physical targets. The children's movement precision improved, their centre of pressure paths decreased, as did the variability in maximal shoulder angles when reaching for virtual objects. Transfer to a situation with physical targets was mainly indicated by increased movement smoothness. Training with motion interactive games seems to improve arm motor control in children with CP. The results highlight the importance of considering both the context and the task itself when investigating kinematic parameters.

  1. A hybrid BMI-based exoskeleton for paresis: EMG control for assisting arm movements.

    Science.gov (United States)

    Kawase, Toshihiro; Sakurada, Takeshi; Koike, Yasuharu; Kansaku, Kenji

    2017-02-01

    Brain-machine interface (BMI) technologies have succeeded in controlling robotic exoskeletons, enabling some paralyzed people to control their own arms and hands. We have developed an exoskeleton asynchronously controlled by EEG signals. In this study, to enable real-time control of the exoskeleton for paresis, we developed a hybrid system with EEG and EMG signals, and the EMG signals were used to estimate its joint angles. Eleven able-bodied subjects and two patients with upper cervical spinal cord injuries (SCIs) performed hand and arm movements, and the angles of the metacarpophalangeal (MP) joint of the index finger, wrist, and elbow were estimated from EMG signals using a formula that we derived to calculate joint angles from EMG signals, based on a musculoskeletal model. The formula was exploited to control the elbow of the exoskeleton after automatic adjustments. Four able-bodied subjects and a patient with upper cervical SCI wore an exoskeleton controlled using EMG signals and were required to perform hand and arm movements to carry and release a ball. Estimated angles of the MP joints of index fingers, wrists, and elbows were correlated well with the measured angles in 11 able-bodied subjects (correlation coefficients were 0.81  ±  0.09, 0.85  ±  0.09, and 0.76  ±  0.13, respectively) and the patients (e.g. 0.91  ±  0.01 in the elbow of a patient). Four able-bodied subjects successfully positioned their arms to adequate angles by extending their elbows and a joint of the exoskeleton, with root-mean-square errors  exoskeleton, successfully carried a ball to a goal in all 10 trials. A BMI-based exoskeleton for paralyzed arms and hands using real-time control was realized by designing a new method to estimate joint angles based on EMG signals, and these may be useful for practical rehabilitation and the support of daily actions.

  2. A hybrid BMI-based exoskeleton for paresis: EMG control for assisting arm movements

    Science.gov (United States)

    Kawase, Toshihiro; Sakurada, Takeshi; Koike, Yasuharu; Kansaku, Kenji

    2017-02-01

    Objective. Brain-machine interface (BMI) technologies have succeeded in controlling robotic exoskeletons, enabling some paralyzed people to control their own arms and hands. We have developed an exoskeleton asynchronously controlled by EEG signals. In this study, to enable real-time control of the exoskeleton for paresis, we developed a hybrid system with EEG and EMG signals, and the EMG signals were used to estimate its joint angles. Approach. Eleven able-bodied subjects and two patients with upper cervical spinal cord injuries (SCIs) performed hand and arm movements, and the angles of the metacarpophalangeal (MP) joint of the index finger, wrist, and elbow were estimated from EMG signals using a formula that we derived to calculate joint angles from EMG signals, based on a musculoskeletal model. The formula was exploited to control the elbow of the exoskeleton after automatic adjustments. Four able-bodied subjects and a patient with upper cervical SCI wore an exoskeleton controlled using EMG signals and were required to perform hand and arm movements to carry and release a ball. Main results. Estimated angles of the MP joints of index fingers, wrists, and elbows were correlated well with the measured angles in 11 able-bodied subjects (correlation coefficients were 0.81  ±  0.09, 0.85  ±  0.09, and 0.76  ±  0.13, respectively) and the patients (e.g. 0.91  ±  0.01 in the elbow of a patient). Four able-bodied subjects successfully positioned their arms to adequate angles by extending their elbows and a joint of the exoskeleton, with root-mean-square errors  exoskeleton, successfully carried a ball to a goal in all 10 trials. Significance. A BMI-based exoskeleton for paralyzed arms and hands using real-time control was realized by designing a new method to estimate joint angles based on EMG signals, and these may be useful for practical rehabilitation and the support of daily actions.

  3. Dopamine transporter imaging in rapid eye movement sleep behavior disorder

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Kyeong; Yoon, In Young; Kim, Jong Min; Jeong, Seok Hoon; Kim, Ji Sun; Lee, Byung Chul; Lee, Won Woo; Kim, Sang Eun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    The pathogenesis of rapid eye movement (REM) sleep behavior disorder (RBD) is still unknown. However, involvement of dopaminergic system in RBD has been hypothesized because of frequent association with degenerative movement disorders such as Parkinson's disease. The purpose of this study was to examine the extent and pattern of loss of dopamine transporter in RBD using FP-CIT SPECT. Fourteen patient with idiopathic RBD (mean age:665 yrs, M:F=10:3) participated in this study. Polysonmography confirmed loss of REM atonia and determined RBD severities by amount of tonic/phasic muscle activity during REM sleep in all cases. To compare with RBD, 14 early idiopathic Parkinson's disease rated as Hoehn and Yahr stage 1 (IPD) and 12 healthy controls were also selected. All participants performed single-photon emission computed tomography (SPECT) imaging 3 hours after injection of [123I]FP-CIT. Regions of interest were drawn on bilateral caudate and putamen, whole striatum and occipital cortex. Specific binding for dopamine transporters (DAT) were calculated using region to occipital uptake ratio based on the transient equilibrium method. Overall mean of DAT density in the striatum was lower in RBD group than controls, and higher than IPD group, However, DAT density in most individual RBD was still within normal range, and total striatal DAT density was not correlated with severity of RBD. Meanwhile, the caudate to putamen uptake ratio (C/P ratio) in RBD group was insignificantly higher than those in healthy controls. Nevertheless, C/P ratio within RBD group was reversely correlated with the RBD severity. Our study suggested that nigrostriatal dopaminergic degeneration could be a part of the pathogenesis of RBD, but not essential for the development of RBD. Further longitudinal evaluation of presynaptic dopaminergic system in idiopathic RBD may guarantee the more understanding for RBD and associated neurodegenerative disease.

  4. Dopamine transporter imaging in rapid eye movement sleep behavior disorder

    International Nuclear Information System (INIS)

    Kim, Yu Kyeong; Yoon, In Young; Kim, Jong Min; Jeong, Seok Hoon; Kim, Ji Sun; Lee, Byung Chul; Lee, Won Woo; Kim, Sang Eun

    2007-01-01

    The pathogenesis of rapid eye movement (REM) sleep behavior disorder (RBD) is still unknown. However, involvement of dopaminergic system in RBD has been hypothesized because of frequent association with degenerative movement disorders such as Parkinson's disease. The purpose of this study was to examine the extent and pattern of loss of dopamine transporter in RBD using FP-CIT SPECT. Fourteen patient with idiopathic RBD (mean age:665 yrs, M:F=10:3) participated in this study. Polysonmography confirmed loss of REM atonia and determined RBD severities by amount of tonic/phasic muscle activity during REM sleep in all cases. To compare with RBD, 14 early idiopathic Parkinson's disease rated as Hoehn and Yahr stage 1 (IPD) and 12 healthy controls were also selected. All participants performed single-photon emission computed tomography (SPECT) imaging 3 hours after injection of [123I]FP-CIT. Regions of interest were drawn on bilateral caudate and putamen, whole striatum and occipital cortex. Specific binding for dopamine transporters (DAT) were calculated using region to occipital uptake ratio based on the transient equilibrium method. Overall mean of DAT density in the striatum was lower in RBD group than controls, and higher than IPD group, However, DAT density in most individual RBD was still within normal range, and total striatal DAT density was not correlated with severity of RBD. Meanwhile, the caudate to putamen uptake ratio (C/P ratio) in RBD group was insignificantly higher than those in healthy controls. Nevertheless, C/P ratio within RBD group was reversely correlated with the RBD severity. Our study suggested that nigrostriatal dopaminergic degeneration could be a part of the pathogenesis of RBD, but not essential for the development of RBD. Further longitudinal evaluation of presynaptic dopaminergic system in idiopathic RBD may guarantee the more understanding for RBD and associated neurodegenerative disease

  5. [Electromyography Analysis of Rapid Eye Movement Sleep Behavior Disorder].

    Science.gov (United States)

    Nakano, Natsuko; Kinoshita, Fumiya; Takada, Hiroki; Nakayama, Meiho

    2018-01-01

    Polysomnography (PSG), which records physiological phenomena including brain waves, breathing status, and muscle tonus, is useful for the diagnosis of sleep disorders as a gold standard. However, measurement and analysis are complex for several specific sleep disorders, such as rapid eye movement (REM) sleep behavior disorder (RBD). Usually, brain waves during REM sleep indicate an awakening pattern under relaxed conditions of skeletal and antigravity muscles. However, these muscles are activated during REM sleep when patients suffer from RBD. These activated muscle movements during REM, so-called REM without atonia (RWA) recorded by PSG, may be related to a neurodegenerative disease such as Parkinson's disease. Thus, careful analysis of RWA is significant not only physically, but also clinically. Commonly, manual viewing measurement analysis of RWA is time-consuming. Therefore, quantitative studies on RWA are rarely reported. A software program, developed from Microsoft Office Excel ® , was used to semiautomatically analyze the RWA ratio extracted from PSG to compare with manual viewing measurement analysis. In addition, a quantitative muscle tonus study was carried out to evaluate the effect of medication on RBD patients. Using this new software program, we were able to analyze RWA on the same cases in approximately 15 min as compared with 60 min in the manual viewing measurement analysis. This software program can not only quantify RWA easily but also identify RWA waves for either phasic or tonic bursts. We consider that this software program will support physicians and scientists in their future research on RBD. We are planning to offer this software program for free to physicians and scientists.

  6. Ictal SPECT in patients with rapid eye movement sleep behaviour disorder.

    Science.gov (United States)

    Mayer, Geert; Bitterlich, Marion; Kuwert, Torsten; Ritt, Philipp; Stefan, Hermann

    2015-05-01

    Rapid eye movement sleep behaviour disorder is a rapid eye movement parasomnia clinically characterized by acting out dreams due to disinhibition of muscle tone in rapid eye movement sleep. Up to 80-90% of the patients with rapid eye movement sleep behaviour disorder develop neurodegenerative disorders within 10-15 years after symptom onset. The disorder is reported in 45-60% of all narcoleptic patients. Whether rapid eye movement sleep behaviour disorder is also a predictor for neurodegeneration in narcolepsy is not known. Although the pathophysiology causing the disinhibition of muscle tone in rapid eye movement sleep behaviour disorder has been studied extensively in animals, little is known about the mechanisms in humans. Most of the human data are from imaging or post-mortem studies. Recent studies show altered functional connectivity between substantia nigra and striatum in patients with rapid eye movement sleep behaviour disorder. We were interested to study which regions are activated in rapid eye movement sleep behaviour disorder during actual episodes by performing ictal single photon emission tomography. We studied one patient with idiopathic rapid eye movement sleep behaviour disorder, one with Parkinson's disease and rapid eye movement sleep behaviour disorder, and two patients with narcolepsy and rapid eye movement sleep behaviour disorder. All patients underwent extended video polysomnography. The tracer was injected after at least 10 s of consecutive rapid eye movement sleep and 10 s of disinhibited muscle tone accompanied by movements registered by an experienced sleep technician. Ictal single photon emission tomography displayed the same activation in the bilateral premotor areas, the interhemispheric cleft, the periaqueductal area, the dorsal and ventral pons and the anterior lobe of the cerebellum in all patients. Our study shows that in patients with Parkinson's disease and rapid eye movement sleep behaviour disorder-in contrast to wakefulness

  7. Restricted Arm Swing Affects Gait Stability and Increased Walking Speed Alters Trunk Movements in Children with Cerebral Palsy

    Science.gov (United States)

    Delabastita, Tijs; Desloovere, Kaat; Meyns, Pieter

    2016-01-01

    Observational research suggests that in children with cerebral palsy, the altered arm swing is linked to instability during walking. Therefore, the current study investigates whether children with cerebral palsy use their arms more than typically developing children, to enhance gait stability. Evidence also suggests an influence of walking speed on gait stability. Moreover, previous research highlighted a link between walking speed and arm swing. Hence, the experiment aimed to explore differences between typically developing children and children with cerebral palsy taking into account the combined influence of restricting arm swing and increasing walking speed on gait stability. Spatiotemporal gait characteristics, trunk movement parameters and margins of stability were obtained using three dimensional gait analysis to assess gait stability of 26 children with cerebral palsy and 24 typically developing children. Four walking conditions were evaluated: (i) free arm swing and preferred walking speed; (ii) restricted arm swing and preferred walking speed; (iii) free arm swing and high walking speed; and (iv) restricted arm swing and high walking speed. Double support time and trunk acceleration variability increased more when arm swing was restricted in children with bilateral cerebral palsy compared to typically developing children and children with unilateral cerebral palsy. Trunk sway velocity increased more when walking speed was increased in children with unilateral cerebral palsy compared to children with bilateral cerebral palsy and typically developing children and in children with bilateral cerebral palsy compared to typically developing children. Trunk sway velocity increased more when both arm swing was restricted and walking speed was increased in children with bilateral cerebral palsy compared to typically developing children. It is proposed that facilitating arm swing during gait rehabilitation can improve gait stability and decrease trunk movements in

  8. Rapid eye movement sleep behaviour disorder in patients with narcolepsy is associated with hypocretin-1 deficiency

    DEFF Research Database (Denmark)

    Knudsen, Stine; Gammeltoft, Steen; Jennum, Poul J

    2010-01-01

    variables were analysed in relation to cataplexy and hypocretin deficiency with uni- and multivariate logistic/linear regression models, controlling for possible rapid eye movement sleep behaviour disorder biasing factors (age, gender, disease duration, previous anti-cataplexy medication). Only hypocretin......Rapid eye movement sleep behaviour disorder is characterized by dream-enacting behaviour and impaired motor inhibition during rapid eye movement sleep. Rapid eye movement sleep behaviour disorder is commonly associated with neurodegenerative disorders, but also reported in narcolepsy with cataplexy....... Most narcolepsy with cataplexy patients lack the sleep-wake, and rapid eye movement sleep, motor-regulating hypocretin neurons in the lateral hypothalamus. In contrast, rapid eye movement sleep behaviour disorder and hypocretin deficiency are rare in narcolepsy without cataplexy. We hypothesized...

  9. Bobath Concept versus constraint-induced movement therapy to improve arm functional recovery in stroke patients: a randomized controlled trial.

    Science.gov (United States)

    Huseyinsinoglu, Burcu Ersoz; Ozdincler, Arzu Razak; Krespi, Yakup

    2012-08-01

    To compare the effects of the Bobath Concept and constraint-induced movement therapy on arm functional recovery among stroke patients with a high level of function on the affected side. A single-blinded, randomized controlled trial. Outpatient physiotherapy department of a stroke unit. A total of 24 patients were randomized to constraint-induced movement therapy or Bobath Concept group. The Bobath Concept group was treated for 1 hour whereas the constraint-induced movement therapy group received training for 3 hours per day during 10 consecutive weekdays. Main measures were the Motor Activity Log-28, the Wolf Motor Function Test, the Motor Evaluation Scale for Arm in Stroke Patients and the Functional Independence Measure. The two groups were found to be homogeneous based on demographic variables and baseline measurements. Significant improvements were seen after treatment only in the 'Amount of use' and 'Quality of movement' subscales of the Motor Activity Log-28 in the constraint-induced movement therapy group over the the Bobath Concept group (P = 0.003; P = 0.01 respectively). There were no significant differences in Wolf Motor Function Test 'Functional ability' (P = 0.137) and 'Performance time' (P = 0.922), Motor Evaluation Scale for Arm in Stroke Patients (P = 0.947) and Functional Independence Measure scores (P = 0.259) between the two intervention groups. Constraint-induced movement therapy and the Bobath Concept have similar efficiencies in improving functional ability, speed and quality of movement in the paretic arm among stroke patients with a high level of function. Constraint-induced movement therapy seems to be slightly more efficient than the Bobath Concept in improving the amount and quality of affected arm use.

  10. Neuromuscular-skeletal origins of predominant patterns of coordination in rhythmic two-joint arm movement.

    Science.gov (United States)

    de Rugy, Aymar; Riek, Stephan; Carson, Richard G

    2006-01-01

    The authors tested for predominant patterns of coordination in the combination of rhythmic flexion-extension (FE) and supination- (SP) at the elbow-joint complex. Participants (N=10) spontaneously established in-phase (supination synchronized with flexion) and antiphase (pronation synchronized with flexion) patterns. In addition, the authors used a motorized robot arm to generate involuntary SP movements with different phase relations with respect to voluntary FE. The involuntarily induced in-phase pattern was accentuated and was more consistent than other patterns. The result provides evidence that the predominance of the in-phase pattern originates in the influence of neuromuscular-skeletal constraints rather than in a preference dictated by perceptual-cognitive factors implicated in voluntary control. Neuromuscular-skeletal constraints involved in the predominance of the in-phase and the antiphase patterns are discussed.

  11. Robotically facilitated virtual rehabilitation of arm transport integrated with finger movement in persons with hemiparesis

    Directory of Open Access Journals (Sweden)

    Davidow Amy

    2011-05-01

    Full Text Available Abstract Background Recovery of upper extremity function is particularly recalcitrant to successful rehabilitation. Robotic-assisted arm training devices integrated with virtual targets or complex virtual reality gaming simulations are being developed to deal with this problem. Neural control mechanisms indicate that reaching and hand-object manipulation are interdependent, suggesting that training on tasks requiring coordinated effort of both the upper arm and hand may be a more effective method for improving recovery of real world function. However, most robotic therapies have focused on training the proximal, rather than distal effectors of the upper extremity. This paper describes the effects of robotically-assisted, integrated upper extremity training. Methods Twelve subjects post-stroke were trained for eight days on four upper extremity gaming simulations using adaptive robots during 2-3 hour sessions. Results The subjects demonstrated improved proximal stability, smoothness and efficiency of the movement path. This was in concert with improvement in the distal kinematic measures of finger individuation and improved speed. Importantly, these changes were accompanied by a robust 16-second decrease in overall time in the Wolf Motor Function Test and a 24-second decrease in the Jebsen Test of Hand Function. Conclusions Complex gaming simulations interfaced with adaptive robots requiring integrated control of shoulder, elbow, forearm, wrist and finger movements appear to have a substantial effect on improving hemiparetic hand function. We believe that the magnitude of the changes and the stability of the patient's function prior to training, along with maintenance of several aspects of the gains demonstrated at retention make a compelling argument for this approach to training.

  12. Robotically facilitated virtual rehabilitation of arm transport integrated with finger movement in persons with hemiparesis.

    Science.gov (United States)

    Merians, Alma S; Fluet, Gerard G; Qiu, Qinyin; Saleh, Soha; Lafond, Ian; Davidow, Amy; Adamovich, Sergei V

    2011-05-16

    Recovery of upper extremity function is particularly recalcitrant to successful rehabilitation. Robotic-assisted arm training devices integrated with virtual targets or complex virtual reality gaming simulations are being developed to deal with this problem. Neural control mechanisms indicate that reaching and hand-object manipulation are interdependent, suggesting that training on tasks requiring coordinated effort of both the upper arm and hand may be a more effective method for improving recovery of real world function. However, most robotic therapies have focused on training the proximal, rather than distal effectors of the upper extremity. This paper describes the effects of robotically-assisted, integrated upper extremity training. Twelve subjects post-stroke were trained for eight days on four upper extremity gaming simulations using adaptive robots during 2-3 hour sessions. The subjects demonstrated improved proximal stability, smoothness and efficiency of the movement path. This was in concert with improvement in the distal kinematic measures of finger individuation and improved speed. Importantly, these changes were accompanied by a robust 16-second decrease in overall time in the Wolf Motor Function Test and a 24-second decrease in the Jebsen Test of Hand Function. Complex gaming simulations interfaced with adaptive robots requiring integrated control of shoulder, elbow, forearm, wrist and finger movements appear to have a substantial effect on improving hemiparetic hand function. We believe that the magnitude of the changes and the stability of the patient's function prior to training, along with maintenance of several aspects of the gains demonstrated at retention make a compelling argument for this approach to training.

  13. Activation of inactivation process initiates rapid eye movement sleep.

    Science.gov (United States)

    Mallick, Birendra Nath; Singh, Abhishek; Khanday, Mudasir Ahmad

    2012-06-01

    Interactions among REM-ON and REM-OFF neurons form the basic scaffold for rapid eye movement sleep (REMS) regulation; however, precise mechanism of their activation and cessation, respectively, was unclear. Locus coeruleus (LC) noradrenalin (NA)-ergic neurons are REM-OFF type and receive GABA-ergic inputs among others. GABA acts postsynaptically on the NA-ergic REM-OFF neurons in the LC and presynaptically on the latter's projection terminals and modulates NA-release on the REM-ON neurons. Normally during wakefulness and non-REMS continuous release of NA from the REM-OFF neurons, which however, is reduced during the latter phase, inhibits the REM-ON neurons and prevents REMS. At this stage GABA from substantia nigra pars reticulate acting presynaptically on NA-ergic terminals on REM-ON neurons withdraws NA-release causing the REM-ON neurons to escape inhibition and being active, may be even momentarily. A working-model showing neurochemical-map explaining activation of inactivation process, showing contribution of GABA-ergic presynaptic inhibition in withdrawing NA-release and dis-inhibition induced activation of REM-ON neurons, which in turn activates other GABA-ergic neurons and shutting-off REM-OFF neurons for the initiation of REMS-generation has been explained. Our model satisfactorily explains yet unexplained puzzles (i) why normally REMS does not appear during waking, rather, appears following non-REMS; (ii) why cessation of LC-NA-ergic-REM-OFF neurons is essential for REMS-generation; (iii) factor(s) which does not allow cessation of REM-OFF neurons causes REMS-loss; (iv) the association of changes in levels of GABA and NA in the brain during REMS and its deprivation and associated symptoms; v) why often dreams are associated with REMS. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Flurbiprofen in rapid eye movement sleep deprivation induced hyperalgesia.

    Science.gov (United States)

    Gürel, Elif Ezgi; Ural, Keremcan; Öztürk, Gülnur; Öztürk, Levent

    2014-04-10

    Rapid eye movement (REM) sleep deprivation induces hyperalgesia in healthy rats. Here, we evaluated the effects of flurbiprofen, an anti-inflammatory and neuroprotective agent, on the increased thermal responses observed in REM sleep deprived rats. Forty female rats were divided into four groups following 96-hour REM sleep deprivation: intraperitoneal injections of placebo, and flurbiprofen 5 mg/kg, 15 mg/kg and 40 mg/kg were made in CONT (n=10), FBP5, FBP15 and FBP40 groups respectively. Pain threshold measurements were performed three times at baseline (0.hour), at the end of REM sleep deprivation (96.hour) and at 1 h after injections (97.hour) by hot plate and tail-flick tests. REM sleep deprivation induced a significant decrease in pain thresholds of all rats (hotplate: 0.hour vs 96.hour, 9.75±2.85 vs 5.10±2.02, pFlurbiprofen in 15 mg/kg and 40 mg/kg doses significantly improved pain tolerance measured by tail flick test (tail flick in FBP15 and FBP40 groups: 96.hour vs 97.hour, 7.01±4.97 vs 8.34±3.61 and 5.06±1.57 vs 7.04±2.49, pFlurbiprofen was used for the first time in a rat model of REM sleep deprivation, and it provided anti-nociceptive effects in 15 mg/kg and 40 mg/kg doses. Flurbiprofen may have the potential for treatment of painful syndromes accompanying insomnia or sleep loss. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. A rapid method of detecting motor blocks in patients with Parkinson's disease during volitional hand movements

    Directory of Open Access Journals (Sweden)

    Popović Mirjana B.

    2002-01-01

    -5%; 56% had MBT% 5-10%; 22% had MBT% 10-15%; 5.5% had MBT% 15-20°% and 2% had MBT% 20-25%. No block lasted more than 25% from the whole movement duration. Table 2 is the summary of mean variability for kinematic indicators of motor block (N, mbt%, t% and for the movement duration T during a 7 day-testing of patients #3. The analysis of calculated data for eight tested PD patients revealed a significant difference (p < 0.01 between healthy controls and three PD patients; data on five PD patients were not significantly different (ns. This method clustered 3 PD patients in the group that experience motor blocks, while the rest were in the group without their significant occurrence. DISCUSSION This algorithm is an additional instrument in classical evaluation of PD patients during their clinical evaluation and treatment. It provides to clinician a rapid feedback on the changes of voluntary hand movements in everyday progress of illness. Furthermore, this method could be of assistance for developing strategies to overcome motor blocks in arm movements at their beginning, as well as for the feedback of the success of drug therapy.

  16. Quantitative Assessment of the Arm/Hand Movements in Parkinson’s Disease Using a Wireless Armband Device

    Directory of Open Access Journals (Sweden)

    Sofija Spasojević

    2017-08-01

    Full Text Available We present an approach for quantitative assessment of the arm/hand movements in patients with Parkinson’s disease (PD, from sensor data acquired with a wearable, wireless armband device (Myo sensor. We propose new Movement Performance Indicators that can be adopted by practitioners for the quantitative evaluation of motor performance and support their clinical evaluations. In addition, specific Movement Performance Indicators can indicate the presence of the bradykinesia symptom. The study includes seventeen PD patients and sixteen age-matched controls. A set of representative arm/hand movements is defined under the supervision of movement disorder specialist. In order to assist the evaluations, and for progress monitoring purposes, as well as for assessing the amount of bradykinesia in PD, a total set of 84 Movement Performance Indicators are computed from the sensor readings. Subsequently, we investigate whether wireless armband device, with the use of the proposed Movement Performance Indicators can be utilized: (1 for objective and precise quantitative evaluation of the arm/hand movements of Parkinson’s patients, (2 for assessment of the bradykinesia motor symptom, and (3 as an adequate low-cost alternative for the sensor glove. We conducted extensive analysis of proposed Movement Performance Indicators and results are indicating following clinically relevant characteristics: (i adequate reliability as measured by ICC; (ii high accuracy in discrimination between the patients and controls, and between the disease stages (support to disease diagnosis and progress monitoring, respectively; (iii substantial difference in comparison between the left-hand and the right-hand movements across controls and patients, as well as between disease stage groups; (iv statistically significant correlation with clinical scales (tapping test and UPDRS-III Motor Score; and (v quantitative evaluation of bradykinesia symptom. Results suggest that the proposed

  17. Design and development of the first exoskeletal garment to enhance arm mobility for children with movement impairments.

    Science.gov (United States)

    Hall, Martha L; Lobo, Michele A

    2017-05-25

    Children with a variety of diagnoses have impairments that limit their arm function. Despite the fact that arm function is important for early learning and activities of daily living, there are few tools to assist movement for these children, and existing devices have challenges related to cost, accessibility, comfort, and aesthetics. In this article, we describe the design process and development of the first garment-based exoskeleton to assist arm movement in young children with movement impairments: the Playskin Lift TM . We outline our design process, which contrasts with the traditional medical model in that it is interdisciplinary, user-centered, and addresses the broad needs of users, rather than device function alone. Then we report the results of field-testing with the initial prototype with respect to our design metrics on a toddler with significant bilateral arm movement impairments. Finally, we summarize our ongoing development aimed at increasing comfort, aesthetics, and accessibility of the garment. The interdisciplinary, user-centered approach to assistive technology design presented here can result in innovative and impactful design solutions that translate to the real world.

  18. A Developmental Study of Static Postural Control and Superimposed Arm Movements in Normal and Slowly Developing Children.

    Science.gov (United States)

    Fisher, Janet M.

    Selected electromyographic parameters underlying static postural control in 4, 6, and 8 year old normally and slowly developing children during performance of selected arm movements were studied. Developmental delays in balance control were assessed by the Cashin Test of Motor Development (1974) and/or the Williams Gross Motor Coordination Test…

  19. Recognition of elementary arm movements using orientation of a tri-axial accelerometer located near the wrist

    International Nuclear Information System (INIS)

    Biswas, Dwaipayan; Cranny, Andy; Maharatna, Koushik; Corda, Daniele; Baldus, Giovanni; Achner, Josy; Klemke, Jasmin; Jöbges, Michael; Ortmann, Steffen

    2014-01-01

    In this paper we present a method for recognising three fundamental movements of the human arm (reach and retrieve, lift cup to mouth, rotation of the arm) by determining the orientation of a tri-axial accelerometer located near the wrist. Our objective is to detect the occurrence of such movements performed with the impaired arm of a stroke patient during normal daily activities as a means to assess their rehabilitation. The method relies on accurately mapping transitions of predefined, standard orientations of the accelerometer to corresponding elementary arm movements. To evaluate the technique, kinematic data was collected from four healthy subjects and four stroke patients as they performed a number of activities involved in a representative activity of daily living, ‘making-a-cup-of-tea’. Our experimental results show that the proposed method can independently recognise all three of the elementary upper limb movements investigated with accuracies in the range 91–99% for healthy subjects and 70–85% for stroke patients. (paper)

  20. Robot-assisted reaching exercise promotes arm movement recovery in chronic hemiparetic stroke: a randomized controlled pilot study

    Directory of Open Access Journals (Sweden)

    Rymer W Zev

    2006-06-01

    Full Text Available Abstract Background and purpose Providing active assistance to complete desired arm movements is a common technique in upper extremity rehabilitation after stroke. Such active assistance may improve recovery by affecting somatosensory input, motor planning, spasticity or soft tissue properties, but it is labor intensive and has not been validated in controlled trials. The purpose of this study was to investigate the effects of robotically administered active-assistive exercise and compare those with free reaching voluntary exercise in improving arm movement ability after chronic stroke. Methods Nineteen individuals at least one year post-stroke were randomized into one of two groups. One group performed 24 sessions of active-assistive reaching exercise with a simple robotic device, while a second group performed a task-matched amount of unassisted reaching. The main outcome measures were range and speed of supported arm movement, range, straightness and smoothness of unsupported reaching, and the Rancho Los Amigos Functional Test of Upper Extremity Function. Results and discussion There were significant improvements with training for range of motion and velocity of supported reaching, straightness of unsupported reaching, and functional movement ability. These improvements were not significantly different between the two training groups. The group that performed unassisted reaching exercise improved the smoothness of their reaching movements more than the robot-assisted group. Conclusion Improvements with both forms of exercise confirmed that repeated, task-related voluntary activation of the damaged motor system is a key stimulus to motor recovery following chronic stroke. Robotically assisting in reaching successfully improved arm movement ability, although it did not provide any detectable, additional value beyond the movement practice that occurred concurrently with it. The inability to detect any additional value of robot-assisted reaching

  1. Analyzing power spectral of electroencephalogram (EEG) signal to identify motoric arm movement using EMOTIV EPOC+

    Science.gov (United States)

    Bustomi, A.; Wijaya, S. K.; Prawito

    2017-07-01

    Rehabilitation of motoric dysfunction from the body becomes the main objective of developing Brain Computer Interface (BCI) technique, especially in the field of medical rehabilitation technology. BCI technology based on electrical activity of the brain, allow patient to be able to restore motoric disfunction of the body and help them to overcome the shortcomings mobility. In this study, EEG signal phenomenon was obtained from EMOTIV EPOC+, the signals were generated from the imagery of lifting arm, and look for any correlation between the imagery of motoric muscle movement against the recorded signals. The signals processing were done in the time-frequency domain, using Wavelet relative power (WRP) as feature extraction, and Support vector machine (SVM) as the classifier. In this study, it was obtained the result of maximum accuracy of 81.3 % using 8 channel (AF3, F7, F3, FC5, FC6, F4, F8, and AF4), 6 channel remaining on EMOTIV EPOC + does not contribute to the improvement of the accuracy of the classification system

  2. Robust adaptive control modeling of human arm movements subject to altered gravity and mechanical loads

    Science.gov (United States)

    Tryfonidis, Michail

    It has been observed that during orbital spaceflight the absence of gravitation related sensory inputs causes incongruence between the expected and the actual sensory feedback resulting from voluntary movements. This incongruence results in a reinterpretation or neglect of gravity-induced sensory input signals. Over time, new internal models develop, gradually compensating for the loss of spatial reference. The study of adaptation of goal-directed movements is the main focus of this thesis. The hypothesis is that during the adaptive learning process the neural connections behave in ways that can be described by an adaptive control method. The investigation presented in this thesis includes two different sets of experiments. A series of dart throwing experiments took place onboard the space station Mir. Experiments also took place at the Biomechanics lab at MIT, where the subjects performed a series of continuous trajectory tracking movements while a planar robotic manipulandum exerted external torques on the subjects' moving arms. The experimental hypothesis for both experiments is that during the first few trials the subjects will perform poorly trying to follow a prescribed trajectory, or trying to hit a target. A theoretical framework is developed that is a modification of the sliding control method used in robotics. The new control framework is an attempt to explain the adaptive behavior of the subjects. Numerical simulations of the proposed framework are compared with experimental results and predictions from competitive models. The proposed control methodology extends the results of the sliding mode theory to human motor control. The resulting adaptive control model of the motor system is robust to external dynamics, even those of negative gain, uses only position and velocity feedback, and achieves bounded steady-state error without explicit knowledge of the system's nonlinearities. In addition, the experimental and modeling results demonstrate that

  3. The nature of arm movement in children with cerebral palsy when using computer-generated exercise games.

    Science.gov (United States)

    Weightman, Andrew; Preston, Nick; Levesley, Martin; Bhakta, Bipin; Holt, Raymond; Mon-Williams, Mark

    2014-05-01

    To compare upper limb kinematics of children with spastic cerebral palsy (CP) using a passive rehabilitation joystick with those of adults and able-bodied children, to better understand the design requirements of computer-based rehabilitation devices. A blocked comparative study involving seven children with spastic CP, nine able-bodied adults and nine able-bodied children, using a joystick system to play a computer game whilst the kinematics of their upper limb were recorded. The translational kinematics of the joystick's end point and the participant's shoulder movement (protraction/retraction) and elbow rotational kinematics (flexion/extension) were analysed for each group. Children with spastic CP matched their able-bodied peers in the time taken to complete the computer task, but this was due to a failure to adhere to the task instructions of travelling along a prescribed straight line when moving between targets. The spastic CP group took longer to initiate the first movement, which showed jerkier trajectories and demonstrated qualitatively different movement patterns when using the joystick, with shoulder movements that were significantly of greater magnitude than the able-bodied participants. Children with spastic CP generate large shoulder and hence trunk movements when using a joystick to undertake computer-generated arm exercises. This finding has implications for the development and use of assistive technologies to encourage exercise and the instructions given to users of such systems. A kinematic analysis of upper limb function of children with CP when using joystick devices is presented. Children with CP may use upper body movements to compensate for limitations in voluntary shoulder and elbow movements when undertaking computer games designed to encourage the practice of arm movement. The design of rehabilitative computer exercise systems should consider movement of the torso/shoulder as it may have implications for the quality of therapy in the

  4. Analysis of the features of untrained human movements based on the multichannel EEG for controlling anthropomorphic robotic arm

    Science.gov (United States)

    Maksimenko, Vladimir; Runnova, Anastasia; Pchelintseva, Svetlana; Efremova, Tatiana; Zhuravlev, Maksim; Pisarchik, Alexander

    2018-04-01

    We have considered time-frequency and spatio-temporal structure of electrical brain activity, associated with real and imaginary movements based on the multichannel EEG recordings. We have found that along with wellknown effects of event-related desynchronization (ERD) in α/μ - rhythms and β - rhythm, these types of activity are accompanied by the either ERS (for real movement) or ERD (for imaginary movement) in low-frequency δ - band, located mostly in frontal lobe. This may be caused by the associated processes of decision making, which take place when subject is deciding either perform the movement or imagine it. Obtained features have been found in untrained subject which it its turn gives the possibility to use our results in the development of brain-computer interfaces for controlling anthropomorphic robotic arm.

  5. The Correlation between Clinical Variables and Sleep Onset Rapid Eye Movement Period Frequencies in Narcoleptic Patients

    Directory of Open Access Journals (Sweden)

    Jin Hwa Jeong

    2010-11-01

    Full Text Available Background and Objective A diagnosis of narcolepsy is defined by less than 8 minutes of mean sleep latency, and two or more sleep onset rapid eye movement periods on the Multiple Sleep Latency Test. This study examined the relationship between the sleep onset rapid eye movement period frequencies during Multiple Sleep Latency Test and narcoleptic symptom severity. Methods From March 2004 to August 2009, 126 patients suffering from excessive daytime sleepiness who visited the Sleep Disorders Clinic of St. Vincent’s Hospital at the Catholic University of Korea were tested by polysomnography and Multiple Sleep Latency Test. Subjects were divided into three groups according to the number of sleep onset rapid eye movement periods that appeared on the Multiple Sleep Latency Test. Symptom severity instruments included the Epworth Sleepiness Scale and the Stanford Center for Narcolepsy Sleep Inventory, and various sleep parameters. In addition, we performed human leukocyte antigen genotyping for human leukocyte antigen-DQB1*0602 on all patients. Results Among the three groups classified by the number of sleep onset rapid eye movement periods during Multiple Sleep Latency Test, we found no significant differences in demographic features, Epworth Sleepiness Scale, and most polysomnographic findings. However, we observed cataplexy, hypnagogic hallucination, sleep paralysis, and human leukocyte antigen-DQB1*0602 positivity more frequently in groups with higher sleep onset rapid eye movement period frequencies. In addition, the proportions of stage II sleep, REM sleep latency from polysomnography, and mean sleep latency and mean REM sleep latency from the Multiple Sleep Latency Test significantly decreased with increasing sleep onset rapid eye movement period frequency. Conclusions In this study, we demonstrated that sleep onset rapid eye movement period frequency during Multiple Sleep Latency Test correlated with sleep architecture, daytime symptom

  6. A reliability study on brain activation during active and passive arm movements supported by an MRI-compatible robot.

    Science.gov (United States)

    Estévez, Natalia; Yu, Ningbo; Brügger, Mike; Villiger, Michael; Hepp-Reymond, Marie-Claude; Riener, Robert; Kollias, Spyros

    2014-11-01

    In neurorehabilitation, longitudinal assessment of arm movement related brain function in patients with motor disability is challenging due to variability in task performance. MRI-compatible robots monitor and control task performance, yielding more reliable evaluation of brain function over time. The main goals of the present study were first to define the brain network activated while performing active and passive elbow movements with an MRI-compatible arm robot (MaRIA) in healthy subjects, and second to test the reproducibility of this activation over time. For the fMRI analysis two models were compared. In model 1 movement onset and duration were included, whereas in model 2 force and range of motion were added to the analysis. Reliability of brain activation was tested with several statistical approaches applied on individual and group activation maps and on summary statistics. The activated network included mainly the primary motor cortex, primary and secondary somatosensory cortex, superior and inferior parietal cortex, medial and lateral premotor regions, and subcortical structures. Reliability analyses revealed robust activation for active movements with both fMRI models and all the statistical methods used. Imposed passive movements also elicited mainly robust brain activation for individual and group activation maps, and reliability was improved by including additional force and range of motion using model 2. These findings demonstrate that the use of robotic devices, such as MaRIA, can be useful to reliably assess arm movement related brain activation in longitudinal studies and may contribute in studies evaluating therapies and brain plasticity following injury in the nervous system.

  7. Chunk concatenation evolves with practice and sleep-related enhancement consolidation in a complex arm movement sequence

    Directory of Open Access Journals (Sweden)

    Blischke Klaus

    2016-06-01

    Full Text Available This paper addresses the notion of chunk concatenation being associated with sleep-related enhancement consolidation of motor sequence memory, thereby essentially contributing to improvements in sequence execution speed. To this end, element movement times of a multi-joint arm movement sequence incorporated in a recent study by Malangré et al. (2014 were reanalyzed. As sequence elements differed with respect to movement distance, element movement times had to be purged from differences solely due to varying trajectory lengths. This was done by dividing each element movement time per subject and trial block by the respective “reference movement time” collected from subjects who had extensively practiced each sequence element in isolation. Any differences in these “relative element movement times” were supposed to reflect element-specific “production costs” imposed solely by the sequence context. Across all subjects non-idiosyncratic, lasting sequence segmentation was shown, and four possible concatenation points (i.e. transition points between successive chunks within the original arm movement sequence were identified. Based on theoretical suppositions derived from previous work with the discrete sequence production task and the dual processor model (Abrahamse et al., 2013, significantly larger improvements in transition speed occurring at these four concatenation points as compared to the five fastest transition positions within the sequence (associated with mere element execution were assumed to indicate increased chunk concatenation. As a result, chunk concatenation was shown to proceed during acquisition with physical practice, and, most importantly, to significantly progress some more during retention following a night of sleep, but not during a waking interval.

  8. Full amenities : the jungle hums with armed guards, planned movements, air-conditioning and cultural realness

    Energy Technology Data Exchange (ETDEWEB)

    Leslie, J.

    2001-06-04

    The working situation of a Canadian consultant asked to work in Ecuador for a one-month period was described. He quickly learned that discretion is an incredibly valuable trait in this country where a number of oil and gas workers have become victims of kidnappings, because the companies that employ them are perceived as having lots of money. Accordingly, the planning for the trip began back in Canada where the worker received inoculations for yellow fever and hepatitis, among others, as well as briefing about personal security while abroad. Upon his arrival, he was met by security guards hired by the company and driven to his hotel in the capital, Quito. He found he was safe to wander inside the hotel at will, as well as just outside. If he wanted to go outside the perimeter, he had to call the company and the guards would meet and escort him, without displaying their weapons. When it came time to travel to the production site deep in the jungle, armed guards were travelling in a vehicle ahead of his, as well as in two vehicles behind him with weapons in full view. All of his movements were planned. The facilities on-site were more than adequate and resembled those found in Canada: flush toilet, air-conditioned sleeping quarters and cafeteria-style food. With air-conditioning available in buildings and in vehicles, it was not too difficult to adjust to the 40 Celsius heat, but one had to be equipped with very dark sunglasses. The high humidity and the heat made it different from conditions experienced in Canada. The people from Ecuador were very friendly and proud to be working on the rigs. Jobs are scarce and the level of poverty high. It was an enjoyable experience overall, as long as one is careful to mitigate risks and take the advice of experts. 3 figs.

  9. Upper arm elevation and repetitive shoulder movements: a general population job exposure matrix based on expert ratings and technical measurements.

    Science.gov (United States)

    Dalbøge, Annett; Hansson, Gert-Åke; Frost, Poul; Andersen, Johan Hviid; Heilskov-Hansen, Thomas; Svendsen, Susanne Wulff

    2016-08-01

    We recently constructed a general population job exposure matrix (JEM), The Shoulder JEM, based on expert ratings. The overall aim of this study was to convert expert-rated job exposures for upper arm elevation and repetitive shoulder movements to measurement scales. The Shoulder JEM covers all Danish occupational titles, divided into 172 job groups. For 36 of these job groups, we obtained technical measurements (inclinometry) of upper arm elevation and repetitive shoulder movements. To validate the expert-rated job exposures against the measured job exposures, we used Spearman rank correlations and the explained variance[Formula: see text] according to linear regression analyses (36 job groups). We used the linear regression equations to convert the expert-rated job exposures for all 172 job groups into predicted measured job exposures. Bland-Altman analyses were used to assess the agreement between the predicted and measured job exposures. The Spearman rank correlations were 0.63 for upper arm elevation and 0.64 for repetitive shoulder movements. The expert-rated job exposures explained 64% and 41% of the variance of the measured job exposures, respectively. The corresponding calibration equations were y=0.5%time+0.16×expert rating and y=27°/s+0.47×expert rating. The mean differences between predicted and measured job exposures were zero due to calibration; the 95% limits of agreement were ±2.9% time for upper arm elevation >90° and ±33°/s for repetitive shoulder movements. The updated Shoulder JEM can be used to present exposure-response relationships on measurement scales. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  10. Computerized method for arm movement assessment in Parkinson's disease and cerebellar syndrome patients

    Directory of Open Access Journals (Sweden)

    Đorđević Olivera

    2005-01-01

    Full Text Available In clinical setting, the symptoms of the impaired motor behavior in patients with different neurological diseases are identified by classical tests incorporated in clinical neurological examination. New computerized methods for objective motor assessment have been recently suggested in the literature. We developed computerized method for assessment and evaluation of arm movement in patients with Parkinson's disease (PD in early phase and in patients with cerebellar syndrome. Method is based on automatic acquisition of hand coordinates during drawing of line and circle, and offline analysis of kinematic parameters (time duration, path length, mean and maximal velocity, velocity profile, and precision. Clinical application is in recognition and follow-up of the impaired kinematic parameters, specific for these two groups of patients. AIM We propose computerized method that consists of two motor tasks: Task 1- drawing a line defined with end points; and Task 2 - drawing a circle defined by referential model. The first task was rather simple with defined direction, and the second included continuous change of the direction that required permanent adjustment. The aim was to detect which kinematic parameters were particularly different in PD and in patients with cerebellar syndrome in relation to healthy controls, and then to apply this method as an additional instrument in clinical evaluation. METHODS Hand trajectories were assessed during simple self-paced 1 point-to-point movement-Task 1; and 2 circle-Task 2, by cordless magnetic mouse in a hand on digitizing board (Drawing board III, 305x457 mm, GTCO Cal Comp Inc. The subjects were seated in a relaxed manner on the chair adjusted to the table height, and instructed not to correct drawn line during performance of a task. The first session was for practicing the tests only, and in the next session, the subjects repeated 5 times each task. All sessions were videotaped with CCD camera. Testing

  11. Rapid movement and instability of an invasive hybrid swarm.

    Science.gov (United States)

    Glotzbecker, Gregory J; Walters, David M; Blum, Michael J

    2016-07-01

    Unstable hybrid swarms that arise following the introduction of non-native species can overwhelm native congeners, yet the stability of invasive hybrid swarms has not been well documented over time. Here, we examine genetic variation and clinal stability across a recently formed hybrid swarm involving native blacktail shiner (Cyprinella venusta) and non-native red shiner (C. lutrensis) in the Upper Coosa River basin, which is widely considered to be a global hot spot of aquatic biodiversity. Examination of phenotypic, multilocus genotypic, and mitochondrial haplotype variability between 2005 and 2011 revealed that the proportion of hybrids has increased over time, with more than a third of all sampled individuals exhibiting admixture in the final year of sampling. Comparisons of clines over time indicated that the hybrid swarm has been rapidly progressing upstream, but at a declining and slower pace than rates estimated from historical collection records. Clinal comparisons also showed that the hybrid swarm has been expanding and contracting over time. Additionally, we documented the presence of red shiner and hybrids farther downstream than prior studies have detected, which suggests that congeners in the Coosa River basin, including all remaining populations of the threatened blue shiner (Cyprinella caerulea), are at greater risk than previously thought.

  12. Interacting noise sources shape patterns of arm movement variability in three-dimensional space.

    Science.gov (United States)

    Apker, Gregory A; Darling, Timothy K; Buneo, Christopher A

    2010-11-01

    Reaching movements are subject to noise in both the planning and execution phases of movement production. The interaction of these noise sources during natural movements is not well understood, despite its importance for understanding movement variability in neurologically intact and impaired individuals. Here we examined the interaction of planning and execution related noise during the production of unconstrained reaching movements. Subjects performed sequences of two movements to targets arranged in three vertical planes separated in depth. The starting position for each sequence was also varied in depth with the target plane; thus required movement sequences were largely contained within the vertical plane of the targets. Each final target in a sequence was approached from two different directions, and these movements were made with or without visual feedback of the moving hand. These combined aspects of the design allowed us to probe the interaction of execution and planning related noise with respect to reach endpoint variability. In agreement with previous studies, we found that reach endpoint distributions were highly anisotropic. The principal axes of movement variability were largely aligned with the depth axis, i.e., the axis along which visual planning related noise would be expected to dominate, and were not generally well aligned with the direction of the movement vector. Our results suggest that visual planning-related noise plays a dominant role in determining anisotropic patterns of endpoint variability in three-dimensional space, with execution noise adding to this variability in a movement direction-dependent manner.

  13. Failure of Arm Movement Control in Stroke Patients, Characterized by Loss of Complexity.

    Science.gov (United States)

    Goh, Segun; Han, Kyungreem; Ryu, Jehkwang; Kim, Seonjin; Choi, MooYoung

    2015-01-01

    We study the mechanism of human arm-posture control by means of nonlinear dynamics and quantitative time series analysis methods. Utilizing linear and nonlinear measures in combination, we find that pathological tremors emerge in patient dynamics and serve as a main feature discriminating between normal and patient groups. The deterministic structure accompanied with loss of complexity inherent in the tremor dynamics is also revealed. To probe the underlying mechanism of the arm-posture dynamics, we further analyze the coupling patterns between joints and components, and discuss their roles in breaking of the organization structure. As a result, we elucidate the mechanisms in the arm-posture dynamics of normal subjects responding to the gravitational force and for the reduction of the dynamic degrees of freedom in the patient dynamics. This study provides an integrated framework for the origin of the loss of complexity in the dynamics of patients as well as the coupling structure in the arm-posture dynamics.

  14. Robotically facilitated virtual rehabilitation of arm transport integrated with finger movement in persons with hemiparesis

    OpenAIRE

    Davidow Amy; Lafond Ian; Saleh Soha; Qiu Qinyin; Fluet Gerard G; Merians Alma S; Adamovich Sergei V

    2011-01-01

    Abstract Background Recovery of upper extremity function is particularly recalcitrant to successful rehabilitation. Robotic-assisted arm training devices integrated with virtual targets or complex virtual reality gaming simulations are being developed to deal with this problem. Neural control mechanisms indicate that reaching and hand-object manipulation are interdependent, suggesting that training on tasks requiring coordinated effort of both the upper arm and hand may be a more effective me...

  15. Clinical features of Parkinson’s disease with and without rapid eye movement sleep behavior disorder

    OpenAIRE

    Liu, Ye; Zhu, Xiao-Ying; Zhang, Xiao-Jin; Kuo, Sheng-Han; Ondo, William G.; Wu, Yun-Cheng

    2017-01-01

    Background Rapid eye movement sleep behavior disorder (RBD) and Parkinson’s disease (PD) are two distinct clinical diseases but they share some common pathological and anatomical characteristics. This study aims to confirm the clinical features of RBD in Chinese PD patients. Methods One hundred fifty PD patients were enrolled from the Parkinson`s disease and Movement Disorders Center in  Department of Neurology, Shanghai General Hospital from January 2013 to August 2014. This study examined P...

  16. Using Functional Electrical Stimulation Mediated by Iterative Learning Control and Robotics to Improve Arm Movement for People With Multiple Sclerosis.

    Science.gov (United States)

    Sampson, Patrica; Freeman, Chris; Coote, Susan; Demain, Sara; Feys, Peter; Meadmore, Katie; Hughes, Ann-Marie

    2016-02-01

    Few interventions address multiple sclerosis (MS) arm dysfunction but robotics and functional electrical stimulation (FES) appear promising. This paper investigates the feasibility of combining FES with passive robotic support during virtual reality (VR) training tasks to improve upper limb function in people with multiple sclerosis (pwMS). The system assists patients in following a specified trajectory path, employing an advanced model-based paradigm termed iterative learning control (ILC) to adjust the FES to improve accuracy and maximise voluntary effort. Reaching tasks were repeated six times with ILC learning the optimum control action from previous attempts. A convenience sample of five pwMS was recruited from local MS societies, and the intervention comprised 18 one-hour training sessions over 10 weeks. The accuracy of tracking performance without FES and the amount of FES delivered during training were analyzed using regression analysis. Clinical functioning of the arm was documented before and after treatment with standard tests. Statistically significant results following training included: improved accuracy of tracking performance both when assisted and unassisted by FES; reduction in maximum amount of FES needed to assist tracking; and less impairment in the proximal arm that was trained. The system was well tolerated by all participants with no increase in muscle fatigue reported. This study confirms the feasibility of FES combined with passive robot assistance as a potentially effective intervention to improve arm movement and control in pwMS and provides the basis for a follow-up study.

  17. Contribution of execution noise to arm movement variability in three-dimensional space.

    Science.gov (United States)

    Apker, Gregory A; Buneo, Christopher A

    2012-01-01

    Reaching movements are subject to noise associated with planning and execution, but precisely how these noise sources interact to determine patterns of endpoint variability in three-dimensional space is not well understood. For frontal plane movements, variability is largest along the depth axis (the axis along which visual planning noise is greatest), with execution noise contributing to this variability along the movement direction. Here we tested whether these noise sources interact in a similar way for movements directed in depth. Subjects performed sequences of two movements from a single starting position to targets that were either both contained within a frontal plane ("frontal sequences") or where the first was within the frontal plane and the second was directed in depth ("depth sequences"). For both sequence types, movements were performed with or without visual feedback of the hand. When visual feedback was available, endpoint distributions for frontal and depth sequences were generally anisotropic, with the principal axes of variability being strongly aligned with the depth axis. Without visual feedback, endpoint distributions for frontal sequences were relatively isotropic and movement direction dependent, while those for depth sequences were similar to those with visual feedback. Overall, the results suggest that in the presence of visual feedback, endpoint variability is dominated by uncertainty associated with planning and updating visually guided movements. In addition, the results suggest that without visual feedback, increased uncertainty in hand position estimation effectively unmasks the effect of execution-related noise, resulting in patterns of endpoint variability that are highly movement direction dependent.

  18. Quality of life in patients with an idiopathic rapid eye movement sleep behaviour disorder in Korea.

    Science.gov (United States)

    Kim, Keun Tae; Motamedi, Gholam K; Cho, Yong Won

    2017-08-01

    There have been few quality of life studies in patients with idiopathic rapid eye movement sleep behaviour disorder. We compared the quality of life in idiopathic rapid eye movement sleep behaviour disorder patients to healthy controls, patients with hypertension, type 2 diabetes mellitus without complication and idiopathic restless legs syndrome. Sixty patients with idiopathic rapid eye movement sleep behaviour disorder (24 female; mean age: 61.43 ± 8.99) were enrolled retrospectively. The diagnosis was established based on sleep history, overnight polysomnography, neurological examination and Mini-Mental State Examination to exclude secondary rapid eye movement sleep behavior disorder. All subjects completed questionnaires, including the Short Form 36-item Health Survey for quality of life. The total quality of life score in idiopathic rapid eye movement sleep behaviour disorder (70.63 ± 20.83) was lower than in the healthy control group (83.38 ± 7.96) but higher than in the hypertension (60.55 ± 24.82), diabetes mellitus (62.42 ± 19.37) and restless legs syndrome (61.77 ± 19.25) groups. The total score of idiopathic rapid eye movement sleep behaviour disorder patients had a negative correlation with the Pittsburg Sleep Quality Index (r = -0.498, P sleep behaviour disorder had a significant negative impact on quality of life, although this effect was less than that of other chronic disorders. This negative effect might be related to a depressive mood associated with the disease. © 2016 European Sleep Research Society.

  19. A system-level mathematical model of Basal Ganglia motor-circuit for kinematic planning of arm movements.

    Science.gov (United States)

    Salimi-Badr, Armin; Ebadzadeh, Mohammad Mehdi; Darlot, Christian

    2018-01-01

    In this paper, a novel system-level mathematical model of the Basal Ganglia (BG) for kinematic planning, is proposed. An arm composed of several segments presents a geometric redundancy. Thus, selecting one trajectory among an infinite number of possible ones requires overcoming redundancy, according to some kinds of optimization. Solving this optimization is assumed to be the function of BG in planning. In the proposed model, first, a mathematical solution of kinematic planning is proposed for movements of a redundant arm in a plane, based on minimizing energy consumption. Next, the function of each part in the model is interpreted as a possible role of a nucleus of BG. Since the kinematic variables are considered as vectors, the proposed model is presented based on the vector calculus. This vector model predicts different neuronal populations in BG which is in accordance with some recent experimental studies. According to the proposed model, the function of the direct pathway is to calculate the necessary rotation of each joint, and the function of the indirect pathway is to control each joint rotation considering the movement of the other joints. In the proposed model, the local feedback loop between Subthalamic Nucleus and Globus Pallidus externus is interpreted as a local memory to store the previous amounts of movements of the other joints, which are utilized by the indirect pathway. In this model, activities of dopaminergic neurons would encode, at short-term, the error between the desired and actual positions of the end-effector. The short-term modulating effect of dopamine on Striatum is also modeled as cross product. The model is simulated to generate the commands of a redundant manipulator. The performance of the model is studied for different reaching movements between 8 points in a plane. Finally, some symptoms of Parkinson's disease such as bradykinesia and akinesia are simulated by modifying the model parameters, inspired by the dopamine depletion

  20. The Relationship between Reduplicated Babble Onset and Laterality Biases in Infant Rhythmic Arm Movements

    Science.gov (United States)

    Iverson, Jana M.; Hall, Amanda J.; Nickel, Lindsay; Wozniak, Robert H.

    2007-01-01

    This study examined changes in rhythmic arm shaking and laterality biases in infants observed longitudinally at three points: just prior to, at, and just following reduplicated babble onset. Infants (ranging in age from 4 to 9 months at babble onset) were videotaped at home as they played with two visually identical audible and silent rattles…

  1. Role of norepinephrine in the regulation of rapid eye movement sleep

    Indian Academy of Sciences (India)

    Sleep and wakefulness are instinctive behaviours that are present across the animal species. Rapid eye movement (REM) sleep is a unique biological phenomenon expressed during sleep. It evolved about 300 million years ago and is noticed in the more evolved animal species. Although it has been objectively identified ...

  2. Extrastriatal monoaminergic dysfunction and enhanced microglial activation in idiopathic rapid eye movement sleep behaviour disorder

    DEFF Research Database (Denmark)

    Stokholm, Morten Gersel; Iranzo, Alex; Østergaard, Karen

    2018-01-01

    BACKGROUND: The majority of patients diagnosed with idiopathic rapid eye movement sleep behaviour disorder (iRBD) progress over time to a Lewy-type α-synucleinopathy such as Parkinson's disease or dementia with Lewy bodies. This in vivo molecular imaging study aimed to investigate if extrastriatal...

  3. Rapid eye movement sleep behavior disorder--diagnostik, årsager og behandling

    DEFF Research Database (Denmark)

    Zoetmulder, Marielle; Jennum, Poul Jørgen

    2009-01-01

    Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by loss of REM sleep and related electromyographic atonia with marked muscular activity and dream enactment behaviour. RBD is seen in 0.5% of the population. It occurs in an idiopathic form and secondarily to medical and neu...

  4. Rapid eye movement sleep behavior disorder--diagnostik, årsager og behandling

    DEFF Research Database (Denmark)

    Zoetmulder, Marielle; Jennum, Poul Jørgen

    2009-01-01

    Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by loss of REM sleep and related electromyographic atonia with marked muscular activity and dream enactment behaviour. RBD is seen in 0.5% of the population. It occurs in an idiopathic form and secondarily to medical...

  5. LINKING MOTOR-RELATED BRAIN POTENTIALS AND VELOCITY PROFILES IN MULTI-JOINT ARM REACHING MOVEMENTS

    Directory of Open Access Journals (Sweden)

    Julià L Amengual

    2014-04-01

    Full Text Available The study of the movement related brain potentials (MRPBs needs accurate technical approaches to disentangle the specific patterns of bran activity during the preparation and execution of movements. During the last forty years, synchronizing the electromiographic activation (EMG of the muscle with the electrophysiological recordings (EEG has been commonly ussed for these purposes. However, new clinical approaches in the study of motor diseases and rehabilitation suggest the demand of new paradigms that might go further into the study of the brain activity associated with the kinematics of movement. As a response to this call, we have used a 3-D hand tracking system with the aim to record continuously the position of an ultrasonic sender located on the hand during the performance of multi-joint self-pace movements. We synchronized the time-series of position of velocity of the sender with the EEG recordings, obtaining specific patterns of brain activity as a function of the fluctuations of the kinematics during the natural movement performance. Additionally, the distribution of the brain activity during the preparation and execution phases of movement was similar that reported previously using the EMG, suggesting the validity of our technique. We claim that this paradigm could be usable in patients because of its simplicity and the potential knowledge that can be extracted from clinical protocols.

  6. Robotic arm

    International Nuclear Information System (INIS)

    Kwech, H.

    1989-01-01

    A robotic arm positionable within a nuclear vessel by access through a small diameter opening and having a mounting tube supported within the vessel and mounting a plurality of arm sections for movement lengthwise of the mounting tube as well as for movement out of a window provided in the wall of the mounting tube is disclosed. An end effector, such as a grinding head or welding element, at an operating end of the robotic arm, can be located and operated within the nuclear vessel through movement derived from six different axes of motion provided by mounting and drive connections between arm sections of the robotic arm. The movements are achieved by operation of remotely-controllable servo motors, all of which are mounted at a control end of the robotic arm to be outside the nuclear vessel. 23 figs

  7. Robotic arm

    Science.gov (United States)

    Kwech, Horst

    1989-04-18

    A robotic arm positionable within a nuclear vessel by access through a small diameter opening and having a mounting tube supported within the vessel and mounting a plurality of arm sections for movement lengthwise of the mounting tube as well as for movement out of a window provided in the wall of the mounting tube. An end effector, such as a grinding head or welding element, at an operating end of the robotic arm, can be located and operated within the nuclear vessel through movement derived from six different axes of motion provided by mounting and drive connections between arm sections of the robotic arm. The movements are achieved by operation of remotely-controllable servo motors, all of which are mounted at a control end of the robotic arm to be outside the nuclear vessel.

  8. Pacing the phasing of leg and arm movements in breaststroke swimming to minimize intra-cyclic velocity fluctuations.

    Directory of Open Access Journals (Sweden)

    Josje van Houwelingen

    Full Text Available In swimming propelling efficiency is partly determined by intra-cyclic velocity fluctuations. The higher these fluctuations are at a given average swimming velocity, the less efficient is the propulsion. This study explored whether the leg-arm coordination (i.e. phase relation ϕ within the breaststroke cycle can be influenced with acoustic pacing, and whether the so induced changes are accompanied by changes in intra-cyclic velocity fluctuations. Twenty-six participants were asked to couple their propulsive leg and arm movements to a double-tone metronome beat and to keep their average swimming velocity constant over trials. The metronome imposed five different phase relations ϕi (90, 135, 180, 225 and 270° of leg-arm coordination. Swimmers adjusted their technique under the influence of the metronome, but failed to comply to the velocity requirement for ϕ = 90 and 135°. For imposed ϕ = 180, 225 and 270°, the intra-cyclic velocity fluctuations increased with increasing ϕ, while average swimming velocity did not differ. This suggests that acoustic pacing may be used to adjust ϕ and thereby performance of breaststroke swimming given the dependence of propelling efficiency on ϕ.

  9. Disrupted rapid eye movement sleep predicts poor declarative memory performance in post-traumatic stress disorder.

    Science.gov (United States)

    Lipinska, Malgorzata; Timol, Ridwana; Kaminer, Debra; Thomas, Kevin G F

    2014-06-01

    Successful memory consolidation during sleep depends on healthy slow-wave and rapid eye movement sleep, and on successful transition across sleep stages. In post-traumatic stress disorder, sleep is disrupted and memory is impaired, but relations between these two variables in the psychiatric condition remain unexplored. We examined whether disrupted sleep, and consequent disrupted memory consolidation, is a mechanism underlying declarative memory deficits in post-traumatic stress disorder. We recruited three matched groups of participants: post-traumatic stress disorder (n = 16); trauma-exposed non-post-traumatic stress disorder (n = 15); and healthy control (n = 14). They completed memory tasks before and after 8 h of sleep. We measured sleep variables using sleep-adapted electroencephalography. Post-traumatic stress disorder-diagnosed participants experienced significantly less sleep efficiency and rapid eye movement sleep percentage, and experienced more awakenings and wake percentage in the second half of the night than did participants in the other two groups. After sleep, post-traumatic stress disorder-diagnosed participants retained significantly less information on a declarative memory task than controls. Rapid eye movement percentage, wake percentage and sleep efficiency correlated with retention of information over the night. Furthermore, lower rapid eye movement percentage predicted poorer retention in post-traumatic stress disorder-diagnosed individuals. Our results suggest that declarative memory consolidation is disrupted during sleep in post-traumatic stress disorder. These data are consistent with theories suggesting that sleep benefits memory consolidation via predictable neurobiological mechanisms, and that rapid eye movement disruption is more than a symptom of post-traumatic stress disorder. © 2014 European Sleep Research Society.

  10. Rapid eye movements during sleep in mice: High trait-like stability qualifies rapid eye movement density for characterization of phenotypic variation in sleep patterns of rodents

    Directory of Open Access Journals (Sweden)

    Fulda Stephany

    2011-11-01

    Full Text Available Abstract Background In humans, rapid eye movements (REM density during REM sleep plays a prominent role in psychiatric diseases. Especially in depression, an increased REM density is a vulnerability marker for depression. In clinical practice and research measurement of REM density is highly standardized. In basic animal research, almost no tools are available to obtain and systematically evaluate eye movement data, although, this would create increased comparability between human and animal sleep studies. Methods We obtained standardized electroencephalographic (EEG, electromyographic (EMG and electrooculographic (EOG signals from freely behaving mice. EOG electrodes were bilaterally and chronically implanted with placement of the electrodes directly between the musculus rectus superior and musculus rectus lateralis. After recovery, EEG, EMG and EOG signals were obtained for four days. Subsequent to the implantation process, we developed and validated an Eye Movement scoring in Mice Algorithm (EMMA to detect REM as singularities of the EOG signal, based on wavelet methodology. Results The distribution of wakefulness, non-REM (NREM sleep and rapid eye movement (REM sleep was typical of nocturnal rodents with small amounts of wakefulness and large amounts of NREM sleep during the light period and reversed proportions during the dark period. REM sleep was distributed correspondingly. REM density was significantly higher during REM sleep than NREM sleep. REM bursts were detected more often at the end of the dark period than the beginning of the light period. During REM sleep REM density showed an ultradian course, and during NREM sleep REM density peaked at the beginning of the dark period. Concerning individual eye movements, REM duration was longer and amplitude was lower during REM sleep than NREM sleep. The majority of single REM and REM bursts were associated with micro-arousals during NREM sleep, but not during REM sleep. Conclusions Sleep

  11. EEG source space analysis of the supervised factor analytic approach for the classification of multi-directional arm movement

    Science.gov (United States)

    Shenoy Handiru, Vikram; Vinod, A. P.; Guan, Cuntai

    2017-08-01

    Objective. In electroencephalography (EEG)-based brain-computer interface (BCI) systems for motor control tasks the conventional practice is to decode motor intentions by using scalp EEG. However, scalp EEG only reveals certain limited information about the complex tasks of movement with a higher degree of freedom. Therefore, our objective is to investigate the effectiveness of source-space EEG in extracting relevant features that discriminate arm movement in multiple directions. Approach. We have proposed a novel feature extraction algorithm based on supervised factor analysis that models the data from source-space EEG. To this end, we computed the features from the source dipoles confined to Brodmann areas of interest (BA4a, BA4p and BA6). Further, we embedded class-wise labels of multi-direction (multi-class) source-space EEG to an unsupervised factor analysis to make it into a supervised learning method. Main Results. Our approach provided an average decoding accuracy of 71% for the classification of hand movement in four orthogonal directions, that is significantly higher (>10%) than the classification accuracy obtained using state-of-the-art spatial pattern features in sensor space. Also, the group analysis on the spectral characteristics of source-space EEG indicates that the slow cortical potentials from a set of cortical source dipoles reveal discriminative information regarding the movement parameter, direction. Significance. This study presents evidence that low-frequency components in the source space play an important role in movement kinematics, and thus it may lead to new strategies for BCI-based neurorehabilitation.

  12. Subversion: Uruguayan Armed Forces Summary of Subversive Movement in Latin America. Part 2

    Science.gov (United States)

    1977-08-12

    Group] j. UP [Union Popular—Popular Unity] k. INI—Grupo MARCHA [Izquierda Nacional Independiente —Grupo MARCHA; National Independent Left—MARCHA...y Populäres—Revolu- tionary Unity Movement of National People’s Groups] z. FA [Frente Amplio—Broad Front] TX Movimiento de Independientes 26...Manuel Andres Dibar Curuchet.’° When he was transferred to the Salto diocese, he was replaced in this post by Paul Dabezies, whose political position was

  13. Context-dependence of Aimed Arm Movements: A Transitory or A Stable Phenomenon?

    Directory of Open Access Journals (Sweden)

    Benjamin Baak

    2014-10-01

    Full Text Available Previous work documented that grasping movements in a typical laboratory context differ widely from those in a more natural context. We evaluate whether this context-dependence changes with experience. Data from 48 subjects (24 female; 24.9 ± 2.7 years of age were (reanalyzed. They had participated in experimental blocks with externally triggered, purposeless and repetitive movements (context L, laboratory-like, and a block with self-initiated, ecologically valid movements embedded in a complex task (context E, everyday-like. Mechanical constraints on grasping were identical in both blocks. A global metric, representing context-dependence across multiple kinematic parameters, did not change appreciably across the 20 trials of a block. Furthermore, the metric was not affected by prior participation in the other block. We conclude that context-dependence of grasping is robust, i.e., it shows little influence of prior experience. This opens the avenue for within-subject designs on context-dependence, e.g., for clinical investigations. Keywords: Motor control, Prehension, Context-dependence, Serial order, Attunement

  14. Research progress on the pathogenesis of rapid eye movement sleep behavior disorder and neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    Hai-yang JIANG

    2017-10-01

    Full Text Available Rapid eye movement sleep behavior disorder (RBD is a sleep disorder characterized by the disappearance of muscle relaxation and enacting one's dreams during rapid eye movement (REM, with most of the dreams being violent or aggressive. Prevalence of RBD, based on population, is 0.38%-2.01%, but it becomes much higher in patients with neurodegenerative diseases, especially α - synucleinopathies. RBD may herald the emergence of α-synucleinopathies by decades, thus it may be used as an effective early marker of neurodegenerative diseases. In this review, we summarized the progress on the pathogenesis of RBD and its relationship with neurodegenerative diseases. DOI: 10.3969/j.issn.1672-6731.2017.10.003

  15. The golden age of rapid eye movement sleep discoveries. 1. Lucretius--1964.

    Science.gov (United States)

    Gottesmann, C

    2001-10-01

    Although there were several premonitory signs of a sleep stage with dreaming, it was only in 1953 that such a stage was identified with certainty. This paper analyses the observations and research related to this dreaming stage (rapid eye movement sleep) until 1964. During these 11 years of research, the main psychological and physiological characteristics of this sleep stage were first described. Where the few results or discussions were later questioned, today's current state of knowledge is briefly outlined.

  16. A single-question screen for rapid eye movement sleep behavior disorder

    DEFF Research Database (Denmark)

    Postuma, Ronald B; Arnulf, Isabelle; Hogl, Birgit

    2012-01-01

    Idiopathic rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia that is an important risk factor for Parkinson's disease (PD) and Lewy body dementia. Its prevalence is unknown. One barrier to determining prevalence is that current screening tools are too long for large......-scale epidemiologic surveys. Therefore, we designed the REM Sleep Behavior Disorder Single-Question Screen (RBD1Q), a screening question for dream enactment with a simple yes/no response....

  17. Impedance is modulated to meet accuracy demands during goal-directed arm movements

    NARCIS (Netherlands)

    Selen, L.P.J.; Beek, P.J.; van Dieen, J.H.

    2006-01-01

    The neuromuscular system is inherently noisy and joint impedance may serve to filter this noise. In the present experiment, we investigated whether individuals modulate joint impedance to meet spatial accuracy demands. Twelve subjects were instructed to make rapid, time constrained, elbow extensions

  18. Intervention to enhance skilled arm and hand movements after stroke: A feasibility study using a new virtual reality system

    Directory of Open Access Journals (Sweden)

    McLaughlin Margaret

    2007-06-01

    Full Text Available Abstract Background Rehabilitation programs designed to develop skill in upper extremity (UE function after stroke require progressive practice that engage and challenge the learner. Virtual realty (VR provides a unique environment where the presentation of stimuli can be controlled systematically for optimal challenge by adapting task difficulty as performance improves. We describe four VR tasks that were developed and tested to improve arm and hand movement skills for individuals with hemiparesis. Methods Two participants with chronic post-stroke paresis and different levels of motor severity attended 12 training sessions lasting 1 to 2 hours each over a 3-week period. Behavior measures and questionnaires were administered pre-, mid-, and post-training. Results Both participants improved VR task performance across sessions. The less impaired participant averaged more time on task, practiced a greater number of blocks per session, and progressed at a faster rate over sessions than the more impaired participant. Impairment level did not change but both participants improved functional ability after training. The less impaired participant increased the number of blocks moved on the Box & Blocks test while the more impaired participant achieved 4 more items on the Functional Test of the Hemiparetic UE. Conclusion Two participants with differing motor severity were able to engage in VR based practice and improve performance over 12 training sessions. We were able to successfully provide individualized, progressive practice based on each participant's level of movement ability and rate of performance improvement.

  19. Controlled, Rapid Uprighting of Molars: A surprisingly Simple Solution The Pivot Arm Appliance.

    Science.gov (United States)

    Warise, Timothy R; Galella, Steve A

    2015-01-01

    In orthodontic cases where the regional anatomy provides limited room for eruption, there is etiologically a higher occurrence of tipped/impacted second molars. Although second molar extraction with third molar replacement is a useful option, the "Pivot Arm Appliance" encourages the uprighting of the second molar as a preferred treatment. The most unique and important attribute of the "Pivot Arm Appliance" is the rotating tube. In cases of access limitation, the disto-occlusal surface of the molar presents as one area that is accessible. Other features of the "Pivot Arm Appliance" include: The position of the rotator tube delivers optimal rotational force through the pivoting action of the tube/arm complex. The "Pivot Arm Appliance" takes advantage of the efficiency and simplicity of a Class I lever system. The anatomical fulcrum being the dense cortical bone located anterior to the ascending ramus. The vertical spring system is compact, reliable and delivers gentle controlled force in rotational direction. The lingual location of the "Pivot Arm Appliance" does not hinder the function of the tongue, impinge on the soft tissue or interfere with normal masticatory function. The ease of placement of the rotator tube and subsequent insertion of the spring. It is well to note the uprighting appliance provides a very useful and practical approach to the unique problem of severely tipped second molars with limited buccal access. The "Pivot Arm Appliance" does not function only in these situations but can be used in all cases of second molar uprighting of a moderate to severe nature.

  20. Analysis of the Biceps Brachii Muscle by Varying the Arm Movement Level and Load Resistance Band

    Directory of Open Access Journals (Sweden)

    Nuradebah Burhan

    2017-01-01

    Full Text Available Biceps brachii muscle illness is one of the common physical disabilities that requires rehabilitation exercises in order to build up the strength of the muscle after surgery. It is also important to monitor the condition of the muscle during the rehabilitation exercise through electromyography (EMG signals. The purpose of this study was to analyse and investigate the selection of the best mother wavelet (MWT function and depth of the decomposition level in the wavelet denoising EMG signals through the discrete wavelet transform (DWT method at each decomposition level. In this experimental work, six healthy subjects comprised of males and females (26 ± 3.0 years and BMI of 22 ± 2.0 were selected as a reference for persons with the illness. The experiment was conducted for three sets of resistance band loads, namely, 5 kg, 9 kg, and 16 kg, as a force during the biceps brachii muscle contraction. Each subject was required to perform three levels of the arm angle positions (30°, 90°, and 150° for each set of resistance band load. The experimental results showed that the Daubechies5 (db5 was the most appropriate DWT method together with a 6-level decomposition with a soft heursure threshold for the biceps brachii EMG signal analysis.

  1. Analysis of the Biceps Brachii Muscle by Varying the Arm Movement Level and Load Resistance Band

    Science.gov (United States)

    Abdullah, Shahrum Shah; Jali, Mohd Hafiz

    2017-01-01

    Biceps brachii muscle illness is one of the common physical disabilities that requires rehabilitation exercises in order to build up the strength of the muscle after surgery. It is also important to monitor the condition of the muscle during the rehabilitation exercise through electromyography (EMG) signals. The purpose of this study was to analyse and investigate the selection of the best mother wavelet (MWT) function and depth of the decomposition level in the wavelet denoising EMG signals through the discrete wavelet transform (DWT) method at each decomposition level. In this experimental work, six healthy subjects comprised of males and females (26 ± 3.0 years and BMI of 22 ± 2.0) were selected as a reference for persons with the illness. The experiment was conducted for three sets of resistance band loads, namely, 5 kg, 9 kg, and 16 kg, as a force during the biceps brachii muscle contraction. Each subject was required to perform three levels of the arm angle positions (30°, 90°, and 150°) for each set of resistance band load. The experimental results showed that the Daubechies5 (db5) was the most appropriate DWT method together with a 6-level decomposition with a soft heursure threshold for the biceps brachii EMG signal analysis. PMID:29138687

  2. Sensory Agreement Guides Kinetic Energy Optimization of Arm Movements during Object Manipulation.

    Directory of Open Access Journals (Sweden)

    Ali Farshchiansadegh

    2016-04-01

    Full Text Available The laws of physics establish the energetic efficiency of our movements. In some cases, like locomotion, the mechanics of the body dominate in determining the energetically optimal course of action. In other tasks, such as manipulation, energetic costs depend critically upon the variable properties of objects in the environment. Can the brain identify and follow energy-optimal motions when these motions require moving along unfamiliar trajectories? What feedback information is required for such optimal behavior to occur? To answer these questions, we asked participants to move their dominant hand between different positions while holding a virtual mechanical system with complex dynamics (a planar double pendulum. In this task, trajectories of minimum kinetic energy were along curvilinear paths. Our findings demonstrate that participants were capable of finding the energy-optimal paths, but only when provided with veridical visual and haptic information pertaining to the object, lacking which the trajectories were executed along rectilinear paths.

  3. Superior arm-movement decoding from cortex with a new, unsupervised-learning algorithm

    Science.gov (United States)

    Makin, Joseph G.; O'Doherty, Joseph E.; Cardoso, Mariana M. B.; Sabes, Philip N.

    2018-04-01

    Objective. The aim of this work is to improve the state of the art for motor-control with a brain-machine interface (BMI). BMIs use neurological recording devices and decoding algorithms to transform brain activity directly into real-time control of a machine, archetypically a robotic arm or a cursor. The standard procedure treats neural activity—vectors of spike counts in small temporal windows—as noisy observations of the kinematic state (position, velocity, acceleration) of the fingertip. Inferring the state from the observations then takes the form of a dynamical filter, typically some variant on Kalman’s (KF). The KF, however, although fairly robust in practice, is optimal only when the relationships between variables are linear and the noise is Gaussian, conditions usually violated in practice. Approach. To overcome these limitations we introduce a new filter, the ‘recurrent exponential-family harmonium’ (rEFH), that models the spike counts explicitly as Poisson-distributed, and allows for arbitrary nonlinear dynamics and observation models. Furthermore, the model underlying the filter is acquired through unsupervised learning, which allows temporal correlations in spike counts to be explained by latent dynamics that do not necessarily correspond to the kinematic state of the fingertip. Main results. We test the rEFH on offline reconstruction of the kinematics of reaches in the plane. The rEFH outperforms the standard, as well as three other state-of-the-art, decoders, across three monkeys, two different tasks, most kinematic variables, and a range of bin widths, amounts of training data, and numbers of neurons. Significance. Our algorithm establishes a new state of the art for offline decoding of reaches—in particular, for fingertip velocities, the variable used for control in most online decoders.

  4. Caffeine increases the velocity of rapid eye movements in unfatigued humans.

    Science.gov (United States)

    Connell, Charlotte J W; Thompson, Benjamin; Turuwhenua, Jason; Hess, Robert F; Gant, Nicholas

    2017-08-01

    Caffeine is a widely used dietary stimulant that can reverse the effects of fatigue on cognitive, motor and oculomotor function. However, few studies have examined the effect of caffeine on the oculomotor system when homeostasis has not been disrupted by physical fatigue. This study examined the influence of a moderate dose of caffeine on oculomotor control and visual perception in participants who were not fatigued. Within a placebo-controlled crossover design, 13 healthy adults ingested caffeine (5 mg·kg -1 body mass) and were tested over 3 h. Eye movements, including saccades, smooth pursuit and optokinetic nystagmus, were measured using infrared oculography. Caffeine was associated with higher peak saccade velocities (472 ± 60° s -1 ) compared to placebo (455 ± 62° s -1 ). Quick phases of optokinetic nystagmus were also significantly faster with caffeine, whereas pursuit eye movements were unchanged. Non-oculomotor perceptual tasks (global motion and global orientation processing) were unaffected by caffeine. These results show that oculomotor control is modulated by a moderate dose of caffeine in unfatigued humans. These effects are detectable in the kinematics of rapid eye movements, whereas pursuit eye movements and visual perception are unaffected. Oculomotor functions may be sensitive to changes in central catecholamines mediated via caffeine's action as an adenosine antagonist, even when participants are not fatigued.

  5. Mechano-chemical signaling maintains the rapid movement of Dictyostelium cells

    International Nuclear Information System (INIS)

    Lombardi, M.L.; Knecht, D.A.; Lee, J.

    2008-01-01

    The survival of Dictyostelium cells depends on their ability to efficiently chemotax, either towards food or to form multicellular aggregates. Although the involvement of Ca 2+ signaling during chemotaxis is well known, it is not clear how this regulates cell movement. Previously, fish epithelial keratocytes have been shown to display transient increases in intracellular calcium ([Ca 2+ ] i ) that are mediated by stretch-activated calcium channels (SACs), which play a role in retraction of the cell body [J. Lee, A. Ishihara, G. Oxford, B. Johnson, and K. Jacobson, Regulation of cell movement is mediated by stretch-activated calcium channels. Nature, 1999. 400(6742): p. 382-6.]. To investigate the involvement of SACs in Dictyostelium movement we performed high resolution calcium imaging in wild-type (NC4A2) Dictyostelium cells to detect changes in [Ca 2+ ] i . We observed small, brief, Ca 2+ transients in randomly moving wild-type cells that were dependent on both intracellular and extracellular sources of calcium. Treatment of cells with the SAC blocker gadolinium (Gd 3+ ) inhibited transients and decreased cell speed, consistent with the involvement of SACs in regulating Dictyostelium motility. Additional support for SAC activity was given by the increase in frequency of Ca 2+ transients when Dictyostelium cells were moving on a more adhesive substratum or when they were mechanically stretched. We conclude that mechano-chemical signaling via SACs plays a major role in maintaining the rapid movement of Dictyostelium cells

  6. Kinematic aiming task: measuring functional changes in hand and arm movements after botulinum toxin-A injections in children with spastic hemiplegia.

    NARCIS (Netherlands)

    Rameckers, E.A.A.; Speth, L.A.; Duysens, J.E.J.; Vles, J.S.; Smits-Engelsman, B.C.M.

    2007-01-01

    OBJECTIVE: To describe different aspects of a kinematic aiming task (KAT) as a quantitative way to assess changes in arm movements within 2 wks after botulinum toxin-A (BTX-A) injections in children with spastic hemiplegia. DESIGN: Intervention study randomized clinical trial; follow-up within 4 wks

  7. Maintenance of equilibrium point control during an unexpectedly loaded rapid limb movement.

    Science.gov (United States)

    Simmons, R W; Richardson, C

    1984-06-08

    Two experiments investigated whether the equilibrium point hypothesis or the mass-spring model of motor control subserves positioning accuracy during spring loaded, rapid, bi-articulated movement. For intact preparations, the equilibrium point hypothesis predicts response accuracy to be determined by a mixture of afferent and efferent information, whereas the mass-spring model predicts positioning to be under a direct control system. Subjects completed a series of load-resisted training trials to a spatial target. The magnitude of a sustained spring load was unexpectedly increased on selected trials. Results indicated positioning accuracy and applied force varied with increases in load, which suggests that the original efferent commands are modified by afferent information during the movement as predicted by the equilibrium point hypothesis.

  8. Rapid eye movement sleep behavior disorder as an outlier detection problem

    DEFF Research Database (Denmark)

    Kempfner, Jacob; Sørensen, Gertrud Laura; Nikolic, M.

    2014-01-01

    OBJECTIVE: Idiopathic rapid eye movement (REM) sleep behavior disorder is a strong early marker of Parkinson's disease and is characterized by REM sleep without atonia and/or dream enactment. Because these measures are subject to individual interpretation, there is consequently need...... for quantitative methods to establish objective criteria. This study proposes a semiautomatic algorithm for the early detection of Parkinson's disease. This is achieved by distinguishing between normal REM sleep and REM sleep without atonia by considering muscle activity as an outlier detection problem. METHODS......: Sixteen healthy control subjects, 16 subjects with idiopathic REM sleep behavior disorder, and 16 subjects with periodic limb movement disorder were enrolled. Different combinations of five surface electromyographic channels, including the EOG, were tested. A muscle activity score was automatically...

  9. Choice reaching with a LEGO arm robot (CoRLEGO): The motor system guides visual attention to movement-relevant information.

    Science.gov (United States)

    Strauss, Soeren; Woodgate, Philip J W; Sami, Saber A; Heinke, Dietmar

    2015-12-01

    We present an extension of a neurobiologically inspired robotics model, termed CoRLEGO (Choice reaching with a LEGO arm robot). CoRLEGO models experimental evidence from choice reaching tasks (CRT). In a CRT participants are asked to rapidly reach and touch an item presented on the screen. These experiments show that non-target items can divert the reaching movement away from the ideal trajectory to the target item. This is seen as evidence attentional selection of reaching targets can leak into the motor system. Using competitive target selection and topological representations of motor parameters (dynamic neural fields) CoRLEGO is able to mimic this leakage effect. Furthermore if the reaching target is determined by its colour oddity (i.e. a green square among red squares or vice versa), the reaching trajectories become straighter with repetitions of the target colour (colour streaks). This colour priming effect can also be modelled with CoRLEGO. The paper also presents an extension of CoRLEGO. This extension mimics findings that transcranial direct current stimulation (tDCS) over the motor cortex modulates the colour priming effect (Woodgate et al., 2015). The results with the new CoRLEGO suggest that feedback connections from the motor system to the brain's attentional system (parietal cortex) guide visual attention to extract movement-relevant information (i.e. colour) from visual stimuli. This paper adds to growing evidence that there is a close interaction between the motor system and the attention system. This evidence contradicts the traditional conceptualization of the motor system as the endpoint of a serial chain of processing stages. At the end of the paper we discuss CoRLEGO's predictions and also lessons for neurobiologically inspired robotics emerging from this work. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  10. Relationships between Rapid Eye Movement Sleep Behavior Disorder and Neurodegenerative Diseases: Clinical Assessments, Biomarkers, and Treatment

    Science.gov (United States)

    Li, Min; Wang, Li; Liu, Jiang-Hong; Zhan, Shu-Qin

    2018-01-01

    Objective: Rapid eye movement sleep behavior disorder (RBD) is characterized by dream enactment and loss of muscle atonia during rapid eye movement sleep. RBD is closely related to α-synucleinopathies including Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. Many studies have investigated the markers of imaging and neurophysiological, genetic, cognitive, autonomic function of RBD and their predictive value for neurodegenerative diseases. This report reviewed the progress of these studies and discussed their limitations and future research directions. Data Sources: Using the combined keywords: “RBD”, “neurodegenerative disease”, “Parkinson disease”, and “magnetic resonance imaging”, the PubMed/MEDLINE literature search was conducted up to January 1, 2018. Study Selection: A total of 150 published articles were initially identified citations. Of the 150 articles, 92 articles were selected after further detailed review. This study referred to all the important English literature in full. Results: Single-nucleotide polymorphisms in SCARB2 (rs6812193) and MAPT (rs12185268) were significantly associated with RBD. The olfactory loss, autonomic dysfunction, marked electroencephalogram slowing during both wakefulness and rapid eye movement sleep, and cognitive impairments were potential predictive markers for RBD conversion to neurodegenerative diseases. Traditional structural imaging studies reported relatively inconsistent results, whereas reduced functional connectivity between the left putamen and substantia nigra and dopamine transporter uptake demonstrated by functional imaging techniques were relatively consistent findings. Conclusions: More longitudinal studies should be conducted to evaluate the predictive value of biomarkers of RBD. Moreover, because the glucose and dopamine metabolisms are not specific for assessing cognitive cognition, the molecular metabolism directly related to cognition should be investigated

  11. Rapid eye movement sleep behavior disorder--diagnostik, årsager og behandling

    DEFF Research Database (Denmark)

    Zoetmulder, Marielle; Jennum, Poul Jørgen

    2009-01-01

    Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by loss of REM sleep and related electromyographic atonia with marked muscular activity and dream enactment behaviour. RBD is seen in 0.5% of the population. It occurs in an idiopathic form and secondarily to medical...... and neurological disease. RBD is related to brainstem pathology. Furthermore, it is increasingly recognized that RBD is frequently related to Parkinsonian disorders and narcolepsy. This article reviews recent knowledge about RBD with focus on the diagnostic process and management....

  12. Rapid Eye Movement Sleep Behavior Disorder in Paraneoplastic Cerebellar Degeneration: Improvement with Immunotherapy.

    Science.gov (United States)

    Vale, Thiago Cardoso; Fernandes do Prado, Lucila Bizari; do Prado, Gilmar Fernandes; Povoas Barsottini, Orlando Graziani; Pedroso, José Luiz

    2016-01-01

    To report two female patients with paraneoplastic cerebellar degeneration (PCD) related to breast cancer that presented with rapid eye movement-sleep behavior disorder (RBD) and improved sleep symptoms with immunotherapy. The two patients were evaluated through clinical scale and polysomnography before and after therapy with intravenous immunoglobulin. RBD was successfully treated with immunotherapy in both patients. Score on the RBD screening questionnaire dropped from 10 to 1 or 0, allied with the normalization of polysomnographic findings. A marked improvement in RBD after immunotherapy in PCD raises the hypothesis that secondary RBD may be an immune-mediated sleep disorder. © 2016 Associated Professional Sleep Societies, LLC.

  13. Comparison between sEMG and force as control interfaces to support planar arm movements in adults with Duchenne: a feasibility study.

    Science.gov (United States)

    Lobo-Prat, Joan; Nizamis, Kostas; Janssen, Mariska M H P; Keemink, Arvid Q L; Veltink, Peter H; Koopman, Bart F J M; Stienen, Arno H A

    2017-07-12

    Adults with Duchenne muscular dystrophy (DMD) can benefit from devices that actively support their arm function. A critical component of such devices is the control interface as it is responsible for the human-machine interaction. Our previous work indicated that surface electromyography (sEMG) and force-based control with active gravity and joint-stiffness compensation were feasible solutions for the support of elbow movements (one degree of freedom). In this paper, we extend the evaluation of sEMG- and force-based control interfaces to simultaneous and proportional control of planar arm movements (two degrees of freedom). Three men with DMD (18-23 years-old) with different levels of arm function (i.e. Brooke scores of 4, 5 and 6) performed a series of line-tracing tasks over a tabletop surface using an experimental active arm support. The arm movements were controlled using three control methods: sEMG-based control, force-based control with stiffness compensation (FSC), and force-based control with no compensation (FNC). The movement performance was evaluated in terms of percentage of task completion, tracing error, smoothness and speed. For subject S1 (Brooke 4) FNC was the preferred method and performed better than FSC and sEMG. FNC was not usable for subject S2 (Brooke 5) and S3 (Brooke 6). Subject S2 presented significantly lower movement speed with sEMG than with FSC, yet he preferred sEMG since FSC was perceived to be too fatiguing. Subject S3 could not successfully use neither of the two force-based control methods, while with sEMG he could reach almost his entire workspace. Movement performance and subjective preference of the three control methods differed with the level of arm function of the participants. Our results indicate that all three control methods have to be considered in real applications, as they present complementary advantages and disadvantages. The fact that the two weaker subjects (S2 and S3) experienced the force-based control

  14. Powered manipulator control arm

    International Nuclear Information System (INIS)

    Le Mouee, Theodore; Vertut, Jean; Marchal, Paul; Germon, J.C.; Petit, Michel

    1975-01-01

    A remote operated control arm for powered manipulators is described. It includes an assembly allowing several movements with position sensors for each movement. The number of possible arm movements equals the number of possible manipulator movements. The control systems may be interrupted as required. One part of the arm is fitted with a system to lock it with respect to another part of the arm without affecting the other movements, so long as the positions of the manipulator and the arm have not been brought into complete coincidence. With this system the locking can be ended when complete concordance is achieved [fr

  15. The inappropriate occurrence of rapid eye movement sleep in narcolepsy is not due to a defect in homeostatic regulation of rapid eye movement sleep.

    Science.gov (United States)

    Roman, Alexis; Meftah, Soraya; Arthaud, Sébastien; Luppi, Pierre-Hervé; Peyron, Christelle

    2018-06-01

    Narcolepsy type 1 is a disabling disorder with four primary symptoms: excessive-daytime-sleepiness, cataplexy, hypnagogic hallucinations, and sleep paralysis. The later three symptoms together with a short rapid eye movement (REM) sleep latency have suggested impairment in REM sleep homeostatic regulation with an enhanced propensity for (i.e. tendency to enter) REM sleep. To test this hypothesis, we challenged REM sleep homeostatic regulation in a recognized model of narcolepsy, the orexin knock-out (Orex-KO) mice and their wild-type (WT) littermates. We first performed 48 hr of REM sleep deprivation using the classic small-platforms-over-water method. We found that narcoleptic mice are similarly REM sleep deprived to WT mice. Although they had shorter sleep latency, Orex-KO mice recovered similarly to WT during the following 10 hr of recovery. Interestingly, Orex-KO mice also had cataplexy episodes immediately after REM sleep deprivation, anticipating REM sleep rebound, at a time of day when cataplexy does not occur in baseline condition. We then evaluated REM sleep propensity using our new automated method of deprivation that performs a specific and efficient REM sleep deprivation. We showed that REM sleep propensity is similar during light phase in Orex-KO and WT mice. However, during the dark phase, REM sleep propensity was not suppressed in Orex-KO mice when hypocretin/orexin neuropeptides are normally released. Altogether our data suggest that in addition to the well-known wake-promoting role of hypocretin/orexin, these neuropeptides would also suppress REM sleep. Therefore, hypocretin/orexin deficiency would facilitate the occurrence of REM sleep at any time of day in an opportunistic manner as seen in human narcolepsy.

  16. RAPID DETECTION OF -THALASSEMIA MUTATIONS IN THAILAND USING MULTIPLEX ARMS

    Directory of Open Access Journals (Sweden)

    D. Shimbhu

    2017-11-01

    Full Text Available The number of mutations underlining b-thalassemia generate a wide variety of different clinical phenotypes. An understanding of the genotype is important for medical personnel in order to provide proper counseling to patients and their families. Characterization of these mutations should aid the planning of a prenatal diagnosis program for bthalassemia. The heterogeneity of the mutations makes it difficult and time consuming to identify the mutation in some individuals. We developed a single-tube multiplex amplification refractory mutation system (multiplex ARMS to identify common ethnic- specific b-thalassemia mutations. Confirmation of multiplex ARMS results was carried out using direct sequencing. Three thousand three hundred twenty two people from Phitsanulok province were screened for the b-thalassemia trait by quantitation of HbA2 with microcolumn chromatography and the genotypes of mutations were characterized using multiplex ARMS and direct sequencing. We found that the deletion at codons 41/42 (-TCTT was the most frequent (48%, codon 17 (A®T (30%, -28 (A®G (6% and IVS-I-1(G®T (6% were the second and third in frequency respectively. A -87 (C®A mutation (4%, IVS II-654 (C®T (2%, codons 71/72 (+A (2% and codon 35 (C®A mutations (2% were also found. These techniques were found to be a valuable tool for analysis of b-thalassemia mutations because they are accurate, simple, and speedy in operation. The application for the diagnosis of severe thalassemia in high-risk pregnancies is promising.

  17. Rapidly Increasing Trend of Recorded Alcohol Consumption Since the End of the Armed Conflict in Sri Lanka.

    Science.gov (United States)

    Nugawela, Manjula D; Lewis, Sarah; Szatkowski, Lisa; Langley, Tessa

    2017-09-01

    To evaluate temporal changes in recorded alcohol consumption in Sri Lanka during and after the armed conflict 1998-2013. District level alcohol sales, and mid-year population data for the whole study period (1998-2013) were consistently available from the Department of Excise and the Department of Census and Statistics for 18 of 25 districts. These data were used to estimate the recorded per capita consumption for the areas that were not directly exposed to the armed conflict. An interrupted time series design was employed to estimate the impact of the end of the armed conflict on recorded adult per capita alcohol consumption of population lived in the 18 districts. Adult per capita recorded alcohol consumption among Sri Lankans living in the 18 districts was 1.59 l of pure alcohol in 1998. This increased up to 2.07 l in 2009 and 2.55 l in 2013. Prior to the end of the conflict in 2009 adult per capita recorded consumption increased by 0.051 l of pure alcohol per year (95% CI: 0.029-0.074, P increased markedly after the end of the conflict. Rapid socio-economic development, alcohol industry penetration and lack of alcohol control strategies during the post-conflict period may have driven this increase. Adult per capita recorded alcohol consumption among Sri Lankans living in 18 districts that were not directly exposed to the armed conflict increased markedly after the end of the conflict in 2009, with a dramatic acceleration in the trend of per capita beer consumption. © The Author 2017. Medical Council on Alcohol and Oxford University Press. All rights reserved.

  18. Probing muscle myosin motor action: x-ray (m3 and m6) interference measurements report motor domain not lever arm movement.

    Science.gov (United States)

    Knupp, Carlo; Offer, Gerald; Ranatunga, K W; Squire, John M

    2009-07-10

    The key question in understanding how force and movement are produced in muscle concerns the nature of the cyclic interaction of myosin molecules with actin filaments. The lever arm of the globular head of each myosin molecule is thought in some way to swing axially on the actin-attached motor domain, thus propelling the actin filament past the myosin filament. Recent X-ray diffraction studies of vertebrate muscle, especially those involving the analysis of interference effects between myosin head arrays in the two halves of the thick filaments, have been claimed to prove that the lever arm moves at the same time as the sliding of actin and myosin filaments in response to muscle length or force steps. It was suggested that the sliding of myosin and actin filaments, the level of force produced and the lever arm angle are all directly coupled and that other models of lever arm movement will not fit the X-ray data. Here, we show that, in addition to interference across the A-band, which must be occurring, the observed meridional M3 and M6 X-ray intensity changes can all be explained very well by the changing diffraction effects during filament sliding caused by heads stereospecifically attached to actin moving axially relative to a population of detached or non-stereospecifically attached heads that remain fixed in position relative to the myosin filament backbone. Crucially, and contrary to previous interpretations, the X-ray interference results provide little direct information about the position of the myosin head lever arm; they are, in fact, reporting relative motor domain movements. The implications of the new interpretation are briefly assessed.

  19. Urotensin II modulates rapid eye movement sleep through activation of brainstem cholinergic neurons

    DEFF Research Database (Denmark)

    Huitron-Resendiz, Salvador; Kristensen, Morten Pilgaard; Sánchez-Alavez, Manuel

    2005-01-01

    administration of UII into the PPT nucleus increases REM sleep without inducing changes in the cortical blood flow. Intracerebroventricular injection of UII enhances both REM sleep and wakefulness and reduces slow-wave sleep 2. Intracerebroventricular, but not local, administration of UII increases cortical...... dorsal tegmental nuclei. This distribution suggests that the UII system is involved in functions regulated by acetylcholine, such as the sleep-wake cycle. Here, we tested the hypothesis that UII influences cholinergic PPT neuron activity and alters rapid eye movement (REM) sleep patterns in rats. Local...... synaptic transmission because it persisted in the presence of TTX and antagonists of ionotropic glutamate, GABA, and glycine receptors. Collectively, these results suggest that UII plays a role in the regulation of REM sleep independently of its cerebrovascular actions by directly activating cholinergic...

  20. Human regional cerebral blood flow during rapid-eye-movement sleep

    DEFF Research Database (Denmark)

    Madsen, P L; Holm, S; Vorstrup, S

    1991-01-01

    Owing to the coupling between CBF and neuronal activity, regional CBF is a reflection of neural activity in different brain regions. In this study we measured regional CBF during polysomnographically well-defined rapid-eye-movement (REM) sleep by the use of single photon emission computerized...... tomography and the new tracer 99mTc-dl-hexamethylpropyleneamine. Eleven healthy volunteers aged between 22 and 27 years were studied. CBF was measured on separate nights during REM sleep and during EEG-verified wakefulness. On awakening from REM sleep, all subjects reported visual dreams. During REM sleep...... dream experiences. On the other hand, the reduced involvement of the inferior frontal cortex observed during REM sleep might explain the poor temporal organization and bizarreness often experienced in dreams....

  1. Chronic escitalopram treatment attenuated the accelerated rapid eye movement sleep transitions after selective rapid eye movement sleep deprivation: a model-based analysis using Markov chains.

    Science.gov (United States)

    Kostyalik, Diána; Vas, Szilvia; Kátai, Zita; Kitka, Tamás; Gyertyán, István; Bagdy, Gyorgy; Tóthfalusi, László

    2014-11-19

    Shortened rapid eye movement (REM) sleep latency and increased REM sleep amount are presumed biological markers of depression. These sleep alterations are also observable in several animal models of depression as well as during the rebound sleep after selective REM sleep deprivation (RD). Furthermore, REM sleep fragmentation is typically associated with stress procedures and anxiety. The selective serotonin reuptake inhibitor (SSRI) antidepressants reduce REM sleep time and increase REM latency after acute dosing in normal condition and even during REM rebound following RD. However, their therapeutic outcome evolves only after weeks of treatment, and the effects of chronic treatment in REM-deprived animals have not been studied yet. Chronic escitalopram- (10 mg/kg/day, osmotic minipump for 24 days) or vehicle-treated rats were subjected to a 3-day-long RD on day 21 using the flower pot procedure or kept in home cage. On day 24, fronto-parietal electroencephalogram, electromyogram and motility were recorded in the first 2 h of the passive phase. The observed sleep patterns were characterized applying standard sleep metrics, by modelling the transitions between sleep phases using Markov chains and by spectral analysis. Based on Markov chain analysis, chronic escitalopram treatment attenuated the REM sleep fragmentation [accelerated transition rates between REM and non-REM (NREM) stages, decreased REM sleep residence time between two transitions] during the rebound sleep. Additionally, the antidepressant avoided the frequent awakenings during the first 30 min of recovery period. The spectral analysis showed that the SSRI prevented the RD-caused elevation in theta (5-9 Hz) power during slow-wave sleep. Conversely, based on the aggregate sleep metrics, escitalopram had only moderate effects and it did not significantly attenuate the REM rebound after RD. In conclusion, chronic SSRI treatment is capable of reducing several effects on sleep which might be the consequence

  2. Rapid Eye Movements (REMs) and visual dream recall in both congenitally blind and sighted subjects

    Science.gov (United States)

    Bértolo, Helder; Mestre, Tiago; Barrio, Ana; Antona, Beatriz

    2017-08-01

    Our objective was to evaluate rapid eye movements (REMs) associated with visual dream recall in sighted subjects and congenital blind. During two consecutive nights polysomnographic recordings were performed at subjects home. REMs were detected by visual inspection on both EOG channels (EOG-H, EOG-V) and further classified as occurring isolated or in bursts. Dream recall was defined by the existence of a dream report. The two groups were compared using t-test and also the two-way ANOVA and a post-hoc Fisher test (for the features diagnosis (blind vs. sighted) and dream recall (yes or no) as a function of time). The average of REM awakenings per subject and the recall ability were identical in both groups. CB had a lower REM density than CS; the same applied to REM bursts and isolated eye movements. In the two-way ANOVA, REM bursts and REM density were significantly different for positive dream recall, mainly for the CB group and for diagnosis; furthermore for both features significant results were obtained for the interaction of time, recall and diagnosis; the interaction of recall and time was however, stronger. In line with previous findings the data show that blind have lower REMs density. However the ability of dream recall in congenitally blind and sighted controls is identical. In both groups visual dream recall is associated with an increase in REM bursts and density. REM bursts also show differences in the temporal profile. REM visual dream recall is associated with increased REMs activity.

  3. Remifentanil inhibits rapid eye movement sleep but not the nocturnal melatonin surge in humans.

    Science.gov (United States)

    Bonafide, Christopher P; Aucutt-Walter, Natalie; Divittore, Nicole; King, Tonya; Bixler, Edward O; Cronin, Arthur J

    2008-04-01

    Postoperative patients are sleep deprived. Opioids, commonly administered for postoperative pain control, are often mistakenly considered inducers of naturally occurring sleep. This study describes the effect of the opioid remifentanil on nocturnal sleep in healthy volunteers. In addition, this study tests the hypothesis that opioid-induced sleep disturbance is caused by a circadian pacemaker disturbance, reflected by suppressed nocturnal plasma concentration of melatonin. Polysomnography was performed in 10 volunteers from 11:00 pm to 7:00 am for four nights at 6-day intervals. On two nights, remifentanil (0.01-0.04 microg x kg x min) was infused from 10:30 pm to 7:00 am, and either a placebo capsule or 3.0 mg melatonin was administered at 10:30 pm. On two additional nights, saline was infused, and the placebo or melatonin capsules were administered at 10:30 pm. Blood was drawn at 12:00 am, 3:00 am, and 6:00 am to measure the plasma concentration of melatonin and cortisol. A repeated-measures analysis of variance model was used to determine the effect of remifentanil on sleep stages, the effect of remifentanil on the plasma concentration of melatonin, and the effect of exogenous melatonin on remifentanil-induced sleep disturbance. Remifentanil inhibited rapid eye movement sleep (14.1 +/- 7.2% to 3.9 +/- 6.9%). The amount of slow wave sleep decreased from 6.8 +/- 7.6% to 3.2 +/- 6.1%, but this decrease was not statistically significant. Remifentanil did not decrease melatonin concentration. Melatonin administration did not prevent remifentanil-induced sleep disturbance. An overnight constant infusion of remifentanil inhibits rapid eye movement sleep without suppressing the nocturnal melatonin surge.

  4. Electroencephalographic findings related with mild cognitive impairment in idiopathic rapid eye movement sleep behavior disorder.

    Science.gov (United States)

    Sasai, Taeko; Matsuura, Masato; Inoue, Yuichi

    2013-12-01

    Mild cognitive impairment (MCI) and electroencephalographic (EEG) slowing have been reported as common findings of idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) and α-synucleinopathies. The objective of this study is to clarify the relation between MCI and physiological markers in iRBD. Cross-sectional study. Yoyogi Sleep Disorder Center. Thirty-one patients with iRBD including 17 younger patients with iRBD (younger than 70 y) and 17 control patients for the younger patients with iRBD. N/A. Montreal Cognitive Assessment (MoCA) and n-polysomnogram (PSG) were conducted of all participants. In patients with iRBD, the factors associated with MCI were explored among parameters of REM sleep without atonia (RWA), score of Sniffin' Sticks Test (threshold-discrimination-identification [TDI] score), RBD morbidity, and RBD severity evaluated with the Japanese version of the RBD questionnaire (RBDQ-JP). The younger iRBD group showed significantly lower alpha power during wake and lower MoCA score than the age-matched control group. MCI was detected in 13 of 17 patients (76.5%) on MoCA in this group. Among patients wtih iRBD, the MoCA score negatively correlated with age, proportion of slow wave sleep, TDI score, and EEG spectral power. Multiple regression analysis provided the following equation: MoCA score = 50.871-0.116*age -5.307*log (δ power during REM sleep) + 0.086*TDI score (R² = 0.598, P sleep), and 0.357 for TDI score (F = 9.900, P sleep and olfactory dysfunction, was revealed to be associated with cognitive decline in idiopathic rapid eye movement sleep behavior disorder.

  5. Memory Reactivation during Rapid Eye Movement Sleep Promotes Its Generalization and Integration in Cortical Stores

    Science.gov (United States)

    Sterpenich, Virginie; Schmidt, Christina; Albouy, Geneviève; Matarazzo, Luca; Vanhaudenhuyse, Audrey; Boveroux, Pierre; Degueldre, Christian; Leclercq, Yves; Balteau, Evelyne; Collette, Fabienne; Luxen, André; Phillips, Christophe; Maquet, Pierre

    2014-01-01

    Study Objectives: Memory reactivation appears to be a fundamental process in memory consolidation. In this study we tested the influence of memory reactivation during rapid eye movement (REM) sleep on memory performance and brain responses at retrieval in healthy human participants. Participants: Fifty-six healthy subjects (28 women and 28 men, age [mean ± standard deviation]: 21.6 ± 2.2 y) participated in this functional magnetic resonance imaging (fMRI) study. Methods and Results: Auditory cues were associated with pictures of faces during their encoding. These memory cues delivered during REM sleep enhanced subsequent accurate recollections but also false recognitions. These results suggest that reactivated memories interacted with semantically related representations, and induced new creative associations, which subsequently reduced the distinction between new and previously encoded exemplars. Cues had no effect if presented during stage 2 sleep, or if they were not associated with faces during encoding. Functional magnetic resonance imaging revealed that following exposure to conditioned cues during REM sleep, responses to faces during retrieval were enhanced both in a visual area and in a cortical region of multisensory (auditory-visual) convergence. Conclusions: These results show that reactivating memories during REM sleep enhances cortical responses during retrieval, suggesting the integration of recent memories within cortical circuits, favoring the generalization and schematization of the information. Citation: Sterpenich V, Schmidt C, Albouy G, Matarazzo L, Vanhaudenhuyse A, Boveroux P, Degueldre C, Leclercq Y, Balteau E, Collette F, Luxen A, Phillips C, Maquet P. Memory reactivation during rapid eye movement sleep promotes its generalization and integration in cortical stores. SLEEP 2014;37(6):1061-1075. PMID:24882901

  6. Morning rapid eye movement sleep naps facilitate broad access to emotional semantic networks.

    Science.gov (United States)

    Carr, Michelle; Nielsen, Tore

    2015-03-01

    The goal of the study was to assess semantic priming to emotion and nonemotion cue words using a novel measure of associational breadth for participants who either took rapid eye movement (REM) or nonrapid eye movement (NREM) naps or who remained awake; assess relation of priming to REM sleep consolidation and REM sleep inertia effects. The associational breadth task was applied in both a priming condition, where cue-words were signaled to be memorized prior to sleep (primed), and a nonpriming condition, where cue words were not memorized (nonprimed). Cue words were either emotional (positive, negative) or nonemotional. Participants were randomly assigned to either an awake (WAKE) or a sleep condition, which was subsequently split into NREM or REM groups depending on stage at awakening. Hospital-based sleep laboratory. Fifty-eight healthy participants (22 male) ages 18 to 35 y (Mage = 23.3 ± 4.08 y). The REM group scored higher than the NREM or WAKE groups on primed, but not nonprimed emotional cue words; the effect was stronger for positive than for negative cue words. However, REM time and percent correlated negatively with degree of emotional priming. Priming occurred for REM awakenings but not for NREM awakenings, even when the latter sleep episodes contained some REM sleep. Associational breadth may be selectively consolidated during REM sleep for stimuli that have been tagged as important for future memory retrieval. That priming decreased with REM time and was higher only for REM sleep awakenings is consistent with two explanatory REM sleep processes: REM sleep consolidation serving emotional downregulation and REM sleep inertia. © 2015 Associated Professional Sleep Societies, LLC.

  7. Clinical features of Parkinson's disease with and without rapid eye movement sleep behavior disorder.

    Science.gov (United States)

    Liu, Ye; Zhu, Xiao-Ying; Zhang, Xiao-Jin; Kuo, Sheng-Han; Ondo, William G; Wu, Yun-Cheng

    2017-01-01

    Rapid eye movement sleep behavior disorder (RBD) and Parkinson's disease (PD) are two distinct clinical diseases but they share some common pathological and anatomical characteristics. This study aims to confirm the clinical features of RBD in Chinese PD patients. One hundred fifty PD patients were enrolled from the Parkinson`s disease and Movement Disorders Center in  Department of Neurology, Shanghai General Hospital from January 2013 to August 2014. This study examined PD patients with or without RBD as determined by the REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ), assessed motor subtype by Unified PD Rating Scale (UPDRS) III at "on" state, and compared the sub-scale scores representing tremor, rigidity, appendicular and axial. Investigators also assessed the Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR), and Parkinson's disease Sleep Scale (PDSS). One hundred fourty one PD patients entered the final study. 30 (21.28%) PD patients had probable RBD (pRBD) diagnosed with a RBDSQ score of 6 or above. There were no significant differences for age, including age of PD onset and PD duration, gender, smoking status, alcohol or coffee use, presence of anosmia or freezing, UPDRS III, and H-Y stages between the pRBD + and pRBD - groups. pRBD + group had lower MMSE scores, higher PDSS scores, and pRBD + PD patients had more prominent proportion in anxiety, depression, constipation, hallucination and a greater prevalence of orthostatic hypotension. pRBD + PD patients exhibited greater changes in non-motor symptoms. However, there was no increase in motor deficits.

  8. Quantitative assessment of motor speech abnormalities in idiopathic rapid eye movement sleep behaviour disorder.

    Science.gov (United States)

    Rusz, Jan; Hlavnička, Jan; Tykalová, Tereza; Bušková, Jitka; Ulmanová, Olga; Růžička, Evžen; Šonka, Karel

    2016-03-01

    Patients with idiopathic rapid eye movement sleep behaviour disorder (RBD) are at substantial risk for developing Parkinson's disease (PD) or related neurodegenerative disorders. Speech is an important indicator of motor function and movement coordination, and therefore may be an extremely sensitive early marker of changes due to prodromal neurodegeneration. Speech data were acquired from 16 RBD subjects and 16 age- and sex-matched healthy control subjects. Objective acoustic assessment of 15 speech dimensions representing various phonatory, articulatory, and prosodic deviations was performed. Statistical models were applied to characterise speech disorders in RBD and to estimate sensitivity and specificity in differentiating between RBD and control subjects. Some form of speech impairment was revealed in 88% of RBD subjects. Articulatory deficits were the most prominent findings in RBD. In comparison to controls, the RBD group showed significant alterations in irregular alternating motion rates (p = 0.009) and articulatory decay (p = 0.01). The combination of four distinctive speech dimensions, including aperiodicity, irregular alternating motion rates, articulatory decay, and dysfluency, led to 96% sensitivity and 79% specificity in discriminating between RBD and control subjects. Speech impairment was significantly more pronounced in RBD subjects with the motor score of the Unified Parkinson's Disease Rating Scale greater than 4 points when compared to other RBD individuals. Simple quantitative speech motor measures may be suitable for the reliable detection of prodromal neurodegeneration in subjects with RBD, and therefore may provide important outcomes for future therapy trials. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Normal Morning Melanin-Concentrating Hormone Levels and No Association with Rapid Eye Movement or Non-Rapid Eye Movement Sleep Parameters in Narcolepsy Type 1 and Type 2

    DEFF Research Database (Denmark)

    Schrölkamp, Maren; Jennum, Poul J; Gammeltoft, Steen

    2017-01-01

    in rapid eye movement (REM) and non-rapid eye movement (NREM) sleep regulation. Hypocretin neurons reciprocally interact with MCH neurons. We hypothesized that altered MCH secretion contributes to the symptoms and sleep abnormalities of narcolepsy and that this is reflected in morning cerebrospinal fluid...... MCH levels. CONCLUSIONS: Our study shows that MCH levels in CSF collected in the morning are normal in narcolepsy and not associated with the clinical symptoms, REM sleep abnormalities, nor number of muscle movements during REM or NREM sleep of the patients. We conclude that morning lumbar CSF MCH......STUDY OBJECTIVES: Other than hypocretin-1 (HCRT-1) deficiency in narcolepsy type 1 (NT1), the neurochemical imbalance of NT1 and narcolepsy type 2 (NT2) with normal HCRT-1 levels is largely unknown. The neuropeptide melanin-concentrating hormone (MCH) is mainly secreted during sleep and is involved...

  10. Dynamic of arm’s micro movements of elite athlete in Olympic exercises Rapid Fire Pistol and Air Pistol

    Directory of Open Access Journals (Sweden)

    V.T. Pyatkov

    2017-04-01

    Full Text Available Purpose: to scientifically substantiate the method of contactless determination of athlete hand’s movements in Olympic exercises with pistol. Material: in the research we used the data of 37 elite athletes in exercise Air Pistol (n=32 and in exercise Rapid Fire Pistol (n=5. Registration of pistol projection’s quickness of movement in target area was realized with the help of computer system Scatt. In total we analyzed 3100 space-time parameters of athletes’ technical-tactic actions in finalizing phase of shooting cycle. Results: we tested innovative method of contactless measuring of athlete’s hand’s micro movements in finalizing phase of shooting cycle. We found uncontrolled deviations from optimal pistol pointing position in vertical, horizontal and sagittal planes. Quickness of athlete hand’s movements in shooting process was determined. Conclusions: we scientifically substantiated the method of contactless determination of athlete hand’s movements at a distance in Olympic exercises with pistol. Besides, we determined the dynamic of athlete’s hand micro movements in Olympic exercises Rapid Fire Pistol та Air Pistol.

  11. Impulse control disorder and rapid eye movement sleep behavior disorder in Parkinson's disease.

    Science.gov (United States)

    Bayard, Sophie; Dauvilliers, Yves; Yu, Huan; Croisier-Langenier, Muriel; Rossignol, Alexia; Charif, Mahmoud; Geny, Christian; Carlander, Bertrand; Cochen De Cock, Valérie

    2014-12-01

    The relationship between ICD and RBD is still not yet understood and the results from the current literature are contradictory in PD. We aimed to explore the association between rapid eye movement (REM) sleep behavior disorder (RBD) and impulse control disorder in Parkinson's disease. Ninety-eight non-demented patients with Parkinson's disease underwent one night of video-polysomnography recording. The diagnosis of RBD was established according to clinical and polysomnographic criteria. Impulse control disorders were determined by a gold standard, semi-structured diagnostic interview. Half of the patients (n = 49) reported clinical history of RBD while polysomnographic diagnosis of RBD was confirmed in 31.6% of the patients (n = 31). At least one impulse control disorder was identified in 21.4% of patients, 22.6% with RBD and 20.9% without. Logistic regression controlling for potential confounders indicated that both clinical RBD (OR = 0.34, 95% CI = 0.07-1.48, P = 0.15) and polysomnographic confirmed RBD diagnoses (OR = 0.1.28, 95% CI = 0.31-5.33, P = 0.34) were not associated with impulse control disorder. In Parkinson's disease, REM Sleep Behavior Disorder is not associated with impulse control disorder. The results of our study do not support the notion that PSG-confirmed RBD and ICD share a common pathophysiology. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Neurophysiological basis of rapid eye movement sleep behavior disorder: informing future drug development

    Directory of Open Access Journals (Sweden)

    Jennum P

    2016-04-01

    Full Text Available Poul Jennum, Julie AE Christensen, Marielle Zoetmulder Department of Clinical Neurophysiology, Faculty of Health Sciences, Danish Center for Sleep Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark Abstract: Rapid eye movement (REM sleep behavior disorder (RBD is a parasomnia characterized by a history of recurrent nocturnal dream enactment behavior and loss of skeletal muscle atonia and increased phasic muscle activity during REM sleep: REM sleep without atonia. RBD and associated comorbidities have recently been identified as one of the most specific and potentially sensitive risk factors for later development of any of the alpha-synucleinopathies: Parkinson’s disease, dementia with Lewy bodies, and other atypical parkinsonian syndromes. Several other sleep-related abnormalities have recently been identified in patients with RBD/Parkinson’s disease who experience abnormalities in sleep electroencephalographic frequencies, sleep–wake transitions, wake and sleep stability, occurrence and morphology of sleep spindles, and electrooculography measures. These findings suggest a gradual involvement of the brainstem and other structures, which is in line with the gradual involvement known in these disorders. We propose that these findings may help identify biomarkers of individuals at high risk of subsequent conversion to parkinsonism. Keywords: motor control, brain stem, hypothalamus, hypocretin

  13. Rapid eye movement sleep behavior disorder in treatment-naïve Parkinson disease patients.

    Science.gov (United States)

    Plomhause, Lucie; Dujardin, Kathy; Duhamel, Alain; Delliaux, Marie; Derambure, Philippe; Defebvre, Luc; Monaca Charley, Christelle

    2013-10-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is a risk factor for dementia in Parkinson disease (PD) patients. The objectives of our study were to prospectively evaluate the frequency of RBD in a sample of treatment-naïve, newly diagnosed PD patients and compare sleep characteristics and cognition in RBD and non-RBD groups. Fifty-seven newly diagnosed PD patients were consecutively recruited in a university medical center. All patients underwent two overnight polysomnography (PSG) sessions and were diagnosed with RBD according to the International Classification of Sleep Disorders, Second Revision criteria. Daytime sleepiness was measured in a multiple sleep latency test (MSLT). Cognition was assessed in a standard neuropsychologic examination. Seventeen PD patients (30%) met the criteria for RBD. The RBD patients and non-RBD patients did not significantly differ in mean age, gender ratio, disease duration, motor symptom subtype and severity, total sleep time, percentage of REM sleep, apnea-hypopnea index, mean oxygen saturation, and importantly cognitive performance. However, non-RBD patients had a significantly shorter mean daytime sleep latency than RBD patients (15 vs. 18 min, respectively; P=.014). A high frequency of RBD was found in our sample of 57 newly diagnosed PD patients. At this stage in the disease, RBD was not found to be associated with other sleep disorders or cognitive decline. Follow-up is needed to assess the risk for developing dementia in early-stage PD patients with RBD. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Neurophysiological basis of rapid eye movement sleep behavior disorder: informing future drug development

    Science.gov (United States)

    Jennum, Poul; Christensen, Julie AE; Zoetmulder, Marielle

    2016-01-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by a history of recurrent nocturnal dream enactment behavior and loss of skeletal muscle atonia and increased phasic muscle activity during REM sleep: REM sleep without atonia. RBD and associated comorbidities have recently been identified as one of the most specific and potentially sensitive risk factors for later development of any of the alpha-synucleinopathies: Parkinson’s disease, dementia with Lewy bodies, and other atypical parkinsonian syndromes. Several other sleep-related abnormalities have recently been identified in patients with RBD/Parkinson’s disease who experience abnormalities in sleep electroencephalographic frequencies, sleep–wake transitions, wake and sleep stability, occurrence and morphology of sleep spindles, and electrooculography measures. These findings suggest a gradual involvement of the brainstem and other structures, which is in line with the gradual involvement known in these disorders. We propose that these findings may help identify biomarkers of individuals at high risk of subsequent conversion to parkinsonism. PMID:27186147

  15. Eruption of a deep-sea mud volcano triggers rapid sediment movement

    Science.gov (United States)

    Feseker, Tomas; Boetius, Antje; Wenzhöfer, Frank; Blandin, Jerome; Olu, Karine; Yoerger, Dana R.; Camilli, Richard; German, Christopher R.; de Beer, Dirk

    2014-01-01

    Submarine mud volcanoes are important sources of methane to the water column. However, the temporal variability of their mud and methane emissions is unknown. Methane emissions were previously proposed to result from a dynamic equilibrium between upward migration and consumption at the seabed by methane-consuming microbes. Here we show non-steady-state situations of vigorous mud movement that are revealed through variations in fluid flow, seabed temperature and seafloor bathymetry. Time series data for pressure, temperature, pH and seafloor photography were collected over 431 days using a benthic observatory at the active Håkon Mosby Mud Volcano. We documented 25 pulses of hot subsurface fluids, accompanied by eruptions that changed the landscape of the mud volcano. Four major events triggered rapid sediment uplift of more than a metre in height, substantial lateral flow of muds at average velocities of 0.4 m per day, and significant emissions of methane and CO2 from the seafloor. PMID:25384354

  16. The rostromedial tegmental nucleus is essential for non-rapid eye movement sleep.

    Directory of Open Access Journals (Sweden)

    Su-Rong Yang

    2018-04-01

    Full Text Available The rostromedial tegmental nucleus (RMTg, also called the GABAergic tail of the ventral tegmental area, projects to the midbrain dopaminergic system, dorsal raphe nucleus, locus coeruleus, and other regions. Whether the RMTg is involved in sleep-wake regulation is unknown. In the present study, pharmacogenetic activation of rat RMTg neurons promoted non-rapid eye movement (NREM sleep with increased slow-wave activity (SWA. Conversely, rats after neurotoxic lesions of 8 or 16 days showed decreased NREM sleep with reduced SWA at lights on. The reduced SWA persisted at least 25 days after lesions. Similarly, pharmacological and pharmacogenetic inactivation of rat RMTg neurons decreased NREM sleep. Electrophysiological experiments combined with optogenetics showed a direct inhibitory connection between the terminals of RMTg neurons and midbrain dopaminergic neurons. The bidirectional effects of the RMTg on the sleep-wake cycle were mimicked by the modulation of ventral tegmental area (VTA/substantia nigra compacta (SNc dopaminergic neuronal activity using a pharmacogenetic approach. Furthermore, during the 2-hour recovery period following 6-hour sleep deprivation, the amount of NREM sleep in both the lesion and control rats was significantly increased compared with baseline levels; however, only the control rats showed a significant increase in SWA compared with baseline levels. Collectively, our findings reveal an essential role of the RMTg in the promotion of NREM sleep and homeostatic regulation.

  17. Tumor Necrosis Factor Antagonism Normalizes Rapid Eye Movement Sleep in Alcohol Dependence

    Science.gov (United States)

    Irwin, Michael R.; Olmstead, Richard; Valladares, Edwin M.; Breen, Elizabeth Crabb; Ehlers, Cindy L.

    2009-01-01

    Background In alcohol dependence, markers of inflammation are associated with increases in rapid eye movement (REM) sleep, which is thought to be a prognostic indicator of alcohol relapse. This study was undertaken to test whether blockade of biologically active tumor necrosis factor-α (TNF-α) normalizes REM sleep in alcohol-dependent adults. Methods In a randomized, placebo-controlled, double-blind, crossover trial, 18 abstinent alcohol-dependent male adults received a single dose of etanercept (25 mg) versus placebo in a counterbalanced order. Polysomnographic sleep was measured at baseline and for 3 nights after the acute dose of etanercept or placebo. Results Compared with placebo, administration of etanercept produced significant decreases in the amount and percentage of REM sleep. Decreases in REM sleep were robust and approached low levels typically found in age-comparable control subjects. Individual differences in biologically active drug as indexed by circulating levels of soluble tumor necrosis factor receptor II negatively correlated with the percentage of REM sleep. Conclusions Pharmacologic neutralization of TNF-α activity is associated with significant reductions in REM sleep in abstinent alcohol-dependent patients. These data suggest that circulating levels of TNF-α may have a physiologic role in the regulation of REM sleep in humans. PMID:19185287

  18. Do patients with rapid eye movement sleep behavior disorder have a disease-specific personality?

    Science.gov (United States)

    Sasai, Taeko; Inoue, Yuichi; Matsuura, Masato

    2012-06-01

    Rapid eye movement sleep behavior disorder (RBD) occurs idiopathically (iRBD), frequently representing a prodromal phase of Parkinson's disease (PD). Previous reports have described that patients with PD have premorbid personality profiles such as industriousness, inflexibility, cautiousness, and lack of novelty seeking. As well, psychological stress often aggravates RBD symptoms. These phenomena encouraged us to investigate personality profiles in iRBD patients. In this study, 53 patients with iRBD and 49 age and sex-matched healthy controls (HC) were enrolled. We used the revised version of the NEO Personality Inventory (NEO-PIR) to measure the personality of these subjects, and the 5 domains and the 30 facets of the NEO-PIR were compared between the two groups. Within the iRBD group, we investigated the association between RBD variables, e.g. the proportion of REM sleep without atonia (RWA/REM), length of RBD morbidity, frequency of vocalization or abnormal behavior, and the variables of NEO-PIR. In the patients, olfactory function was significantly lower than that of healthy controls, but the inventory differences were not significant. The inventory showed no association with any RBD variable, or the existence of aggravation of these symptoms triggered by psychological stress, or olfactory dysfunction. These results suggest that RBD patients do not have a personality profile that might predict PD development. The personality profile itself cannot explain the psychological-stress-dependent aggravation of RBD symptoms. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Rapid eye movement sleep behaviour disorder and striatal dopamine depletion in patients with Parkinson's disease.

    Science.gov (United States)

    Chung, S J; Lee, Y; Lee, J J; Lee, P H; Sohn, Y H

    2017-10-01

    Rapid eye movement sleep behaviour disorder (RBD) is related to striatal dopamine depletion. This study was performed to confirm whether clinically probable RBD (cpRBD) in patients with Parkinson's disease (PD) is associated with a specific pattern of striatal dopamine depletion. A prospective survey was conducted using the RBD Screening Questionnaire (RBDSQ) in 122 patients with PD who had undergone dopamine transporter (DAT) positron emission tomography scan. Patients with cpRBD (RBDSQ ≥ 7) exhibited greater motor deficits, predominantly in the less-affected side and axial symptoms, and were prescribed higher levodopa-equivalent doses at follow-up than those without cpRBD (RBDSQ ≤ 4), despite their similar disease and treatment durations. Compared to patients without cpRBD, those with cpRBD showed lower DAT activities in the putamen, particularly in the less-affected side in all putaminal subregions, and a tendency to be lower in the ventral striatum. In addition, greater motor deficits in patients with cpRBD than in those without cpRBD remained significant after controlling for DAT binding in the putamen and other confounding variables. These results demonstrated that the presence of RBD in patients with PD is associated with different patterns of both motor deficit distribution and striatal DAT depletion, suggesting that the presence of RBD represents a distinct PD subtype with a malignant motor parkinsonism. © 2017 EAN.

  20. Sleep alterations in mammals: did aquatic conditions inhibit rapid eye movement sleep?

    Science.gov (United States)

    Madan, Vibha; Jha, Sushil K

    2012-12-01

    Sleep has been studied widely in mammals and to some extent in other vertebrates. Higher vertebrates such as birds and mammals have evolved an inimitable rapid eye movement (REM) sleep state. During REM sleep, postural muscles become atonic and the temperature regulating machinery remains suspended. Although REM sleep is present in almost all the terrestrial mammals, the aquatic mammals have either radically reduced or completely eliminated REM sleep. Further, we found a significant negative correlation between REM sleep and the adaptation of the organism to live on land or in water. The amount of REM sleep is highest in terrestrial mammals, significantly reduced in semi-aquatic mammals and completely absent or negligible in aquatic mammals. The aquatic mammals are obligate swimmers and have to surface at regular intervals for air. Also, these animals live in thermally challenging environments, where the conductive heat loss is approximately ~90 times greater than air. Therefore, they have to be moving most of the time. As an adaptation, they have evolved unihemispheric sleep, during which they can rove as well as rest. A condition that immobilizes muscle activity and suspends the thermoregulatory machinery, as happens during REM sleep, is not suitable for these animals. It is possible that, in accord with Darwin's theory, aquatic mammals might have abolished REM sleep with time. In this review, we discuss the possibility of the intrinsic role of aquatic conditions in the elimination of REM sleep in the aquatic mammals.

  1. Rapid eye movement-sleep is reduced in patients with acute uncomplicated diverticulitis—an observational study

    Directory of Open Access Journals (Sweden)

    Chenxi Huang

    2015-08-01

    Full Text Available Introduction. Sleep disturbances are commonly found in patients in the postoperative period. Sleep disturbances may give rise to several complications including cardiopulmonary instability, transient cognitive dysfunction and prolonged convalescence. Many factors including host inflammatory responses are believed to cause postoperative sleep disturbances, as inflammatory responses can alter sleep architecture through cytokine-brain interactions. Our aim was to investigate alteration of sleep architecture during acute infection and its relationships to inflammation and clinical symptoms.Materials & Methods. In this observational study, we included patients with acute uncomplicated diverticulitis as a model to investigate the isolated effects of inflammatory responses on sleep. Eleven patients completed the study. Patients were admitted and treated with antibiotics for two nights, during which study endpoints were measured by polysomnography recordings, self-reported discomfort scores and blood samples of cytokines. One month later, the patients, who now were in complete remission, were readmitted and the endpoints were re-measured (the baseline values.Results. Total sleep time was reduced 4% and 7% the first (p = 0.006 and second (p = 0.014 nights of diverticulitis, compared to baseline, respectively. The rapid eye movement sleep was reduced 33% the first night (p = 0.016, compared to baseline. Moreover, plasma IL-6 levels were correlated to non-rapid eye movement sleep, rapid eye movement sleep and fatigue.Conclusion. Total sleep time and rapid eye movement sleep were reduced during nights with active diverticulitis and correlated with markers of inflammation.

  2. Velocity-based planning of rapid elbow movements expands the control scheme of the equilibrium point hypothesis.

    Science.gov (United States)

    Suzuki, Masataka; Yamazaki, Yoshihiko

    2005-01-01

    According to the equilibrium point hypothesis of voluntary motor control, control action of muscles is not explicitly computed, but rather arises as a consequence of interaction between moving equilibrium position, current kinematics and stiffness of the joint. This approach is attractive as it obviates the need to explicitly specify the forces controlling limb movements. However, many debatable aspects of this hypothesis remain in the manner of specification of the equilibrium point trajectory and muscle activation (or its stiffness), which elicits a restoring force toward the planned equilibrium trajectory. In this study, we expanded the framework of this hypothesis by assuming that the control system uses the velocity measure as the origin of subordinate variables scaling descending commands. The velocity command is translated into muscle control inputs by second order pattern generators, which yield reciprocal command and coactivation commands, and create alternating activation of the antagonistic muscles during movement and coactivation in the post-movement phase, respectively. The velocity command is also integrated to give a position command specifying a moving equilibrium point. This model is purely kinematics-dependent, since the descending commands needed to modulate the visco-elasticity of muscles are implicitly given by simple parametric specifications of the velocity command alone. The simulated movements of fast elbow single-joint movements corresponded well with measured data performed over a wide range of movement distances, in terms of both muscle excitations and kinematics. Our proposal on a synthesis for the equilibrium point approach and velocity command, may offer some insights into the control scheme of the single-joint arm movements.

  3. Feedback Control of arm movements using Neuro-Muscular Electrical Stimulation (NMES combined with a lockable, passive exoskeleton for gravity compensation

    Directory of Open Access Journals (Sweden)

    Christian eKlauer

    2014-09-01

    Full Text Available Within the European project MUNDUS, an assistive framework was developed for the support of arm and hand functions during daily life activities in severely impaired people. Potential users of this system are patients with high-level spinal cord injury and neurodegenerative neuromuscular diseases, such as amyotrophic lateral sclerosis, Friedreich ataxia, and multiple sclerosis. This contribution aims at designing a feedback control system for Neuro-Muscular Electrical Stimulation (NMES to enable reaching functions in people with no residual voluntary control of the arm due to upper motor neuron lesions after spinal cord injury. NMES is applied to the deltoids and the biceps muscles and integrated with a three degrees of freedom (DoFs passive exoskeleton, which partially compensates gravitational forces and allows to lock each DOF. The user is able to choose the target hand position and to trigger actions using an eyetracker system. The target position is selected by using the eyetracker and determined by a marker-based tracking system using Microsoft Kinect. A central controller, i.e. a finite state machine, issues a sequence of basic movement commands to the real-time arm controller. The NMES control algorithm sequentially controls each joint angle while locking the other DoFs. Daily activities, such as drinking, brushing hair, pushing an alarm button, etc., can be supported by the system. The robust and easily tunable control approach was evaluated with five healthy subjects during a drinking task. Subjects were asked to remain passive and to allow NMES to induce the movements. In all of them, the controller was able to perform the task, and a mean hand positioning error of less than five centimeters was achieved. The average total time duration for moving the hand from a rest position to a drinking cup, for moving the cup to the mouth and back, and for finally returning the arm to the rest position was 71 seconds.

  4. Evaluation of the effects of the Arm Light Exoskeleton on movement execution and muscle activities: a pilot study on healthy subjects.

    Science.gov (United States)

    Pirondini, Elvira; Coscia, Martina; Marcheschi, Simone; Roas, Gianluca; Salsedo, Fabio; Frisoli, Antonio; Bergamasco, Massimo; Micera, Silvestro

    2016-01-23

    Exoskeletons for lower and upper extremities have been introduced in neurorehabilitation because they can guide the patient's limb following its anatomy, covering many degrees of freedom and most of its natural workspace, and allowing the control of the articular joints. The aims of this study were to evaluate the possible use of a novel exoskeleton, the Arm Light Exoskeleton (ALEx), for robot-aided neurorehabilitation and to investigate the effects of some rehabilitative strategies adopted in robot-assisted training. We studied movement execution and muscle activities of 16 upper limb muscles in six healthy subjects, focusing on end-effector and joint kinematics, muscle synergies, and spinal maps. The subjects performed three dimensional point-to-point reaching movements, without and with the exoskeleton in different assistive modalities and control strategies. The results showed that ALEx supported the upper limb in all modalities and control strategies: it reduced the muscular activity of the shoulder's abductors and it increased the activity of the elbow flexors. The different assistive modalities favored kinematics and muscle coordination similar to natural movements, but the muscle activity during the movements assisted by the exoskeleton was reduced with respect to the movements actively performed by the subjects. Moreover, natural trajectories recorded from the movements actively performed by the subjects seemed to promote an activity of muscles and spinal circuitries more similar to the natural one. The preliminary analysis on healthy subjects supported the use of ALEx for post-stroke upper limb robotic assisted rehabilitation, and it provided clues on the effects of different rehabilitative strategies on movement and muscle coordination.

  5. The Atomic Papers: A citizen's guide to selected books and articles on the bomb, the arms race, nuclear power, the peace movement, and related issues

    International Nuclear Information System (INIS)

    Burns, G.

    1984-01-01

    The Atomic Papers annotates over 800 books published since 1945 and approximately 300 periodical articles since 1980 on every facet of the nuclear dilemma: the development and effects of the bomb, the arms race, nuclear proliferation, and the peace movement. Work on both sides of the nuclear power controversy also receives substantial attention. All references are to English-language material, and nearly half are to work published since 1980. The concluding chapter, ''The Art of Fission,'' describes over one hundred novels and stories with nuclear themes published since 1945--and, in a few cases, before that date

  6. [Syndrome of rapid eye movement sleep behavior disorder and nocturia in Parkinson's disease].

    Science.gov (United States)

    Nodel, M R; Ukraintseva, Yu V; Yakhno, N N

    Parasomnia, a syndrome of rapid eye movement sleep behavior disorder (RBD), is a common non-motor impairment in patients with Parkinson's disease (PD). The relationship between RBD with other symptoms of PD affecting night sleep, in particular, nocturia, is understudied. An aim of the study was to determine the symptoms related to night sleep disturbances in PD patients with RBD and assess the dynamics of these disturbances with the disease progression taking into account RBD onset. One hundred and forty patients (72 male and 68 female) with PD without dementia (mean age 61.98±0.79 years, PD stage - 2.35±0.05, duration 5.82±90.65 years) were examined. Motor disorders were assessed with the unified Parkinson's disease rating scale (UPDRS), sleep disturbances and frequent night urinations were evaluated with the Parkinson's Disease Sleep Scale (PDSS). The diagnosis of probable RBD was based on reports of patients or their relatives on the dream-related motor activity and vocalization. Quality-of-life was evaluated with the Parkinson's Disease Questionnaire (PDQ-39). Patients were followed up after 2.5 years. Probable RBD was diagnosed in 46.43% of patients, including 30.77%, who developed the syndrome before the manifestation of motor symptoms, 16.92% patients with simultaneous development of RBD and motor symptoms and 52.31% with RBD development >2 years after motor disorders. Patients with RBD differed from those without parasomnia by the higher severity of nocturia. After 2.5 years of follow-up, the severity of disease was greater in patients with RBD assessed by UPDRS, quality-of-life indices, severity of nocturia and episodes of nocturia. The highest frequency of episodes of nocturia was noted in patients with early onset of RBD before the manifestation of motor symptoms. RBD in patients with PD is associated with the rapid progress of nocturia, higher degree of worsening of daily activities and deterioration of quality of life. The relationship between RBD

  7. Validation of an integrated software for the detection of rapid eye movement sleep behavior disorder.

    Science.gov (United States)

    Frauscher, Birgit; Gabelia, David; Biermayr, Marlene; Stefani, Ambra; Hackner, Heinz; Mitterling, Thomas; Poewe, Werner; Högl, Birgit

    2014-10-01

    Rapid eye movement sleep without atonia (RWA) is the polysomnographic hallmark of REM sleep behavior disorder (RBD). To partially overcome the disadvantages of manual RWA scoring, which is time consuming but essential for the accurate diagnosis of RBD, we aimed to validate software specifically developed and integrated with polysomnography for RWA detection against the gold standard of manual RWA quantification. Academic referral center sleep laboratory. Polysomnographic recordings of 20 patients with RBD and 60 healthy volunteers were analyzed. N/A. Motor activity during REM sleep was quantified manually and computer assisted (with and without artifact detection) according to Sleep Innsbruck Barcelona (SINBAR) criteria for the mentalis ("any," phasic, tonic electromyographic [EMG] activity) and the flexor digitorum superficialis (FDS) muscle (phasic EMG activity). Computer-derived indices (with and without artifact correction) for "any," phasic, tonic mentalis EMG activity, phasic FDS EMG activity, and the SINBAR index ("any" mentalis + phasic FDS) correlated well with the manually derived indices (all Spearman rhos 0.66-0.98). In contrast with computerized scoring alone, computerized scoring plus manual artifact correction (median duration 5.4 min) led to a significant reduction of false positives for "any" mentalis (40%), phasic mentalis (40.6%), and the SINBAR index (41.2%). Quantification of tonic mentalis and phasic FDS EMG activity was not influenced by artifact correction. The computer algorithm used here appears to be a promising tool for REM sleep behavior disorder detection in both research and clinical routine. A short check for plausibility of automatic detection should be a basic prerequisite for this and all other available computer algorithms. © 2014 Associated Professional Sleep Societies, LLC.

  8. Apnea-induced rapid eye movement sleep disruption impairs human spatial navigational memory.

    Science.gov (United States)

    Varga, Andrew W; Kishi, Akifumi; Mantua, Janna; Lim, Jason; Koushyk, Viachaslau; Leibert, David P; Osorio, Ricardo S; Rapoport, David M; Ayappa, Indu

    2014-10-29

    Hippocampal electrophysiology and behavioral evidence support a role for sleep in spatial navigational memory, but the role of particular sleep stages is less clear. Although rodent models suggest the importance of rapid eye movement (REM) sleep in spatial navigational memory, a similar role for REM sleep has never been examined in humans. We recruited subjects with severe obstructive sleep apnea (OSA) who were well treated and adherent with continuous positive airway pressure (CPAP). Restricting CPAP withdrawal to REM through real-time monitoring of the polysomnogram provides a novel way of addressing the role of REM sleep in spatial navigational memory with a physiologically relevant stimulus. Individuals spent two different nights in the laboratory, during which subjects performed timed trials before and after sleep on one of two unique 3D spatial mazes. One night of sleep was normally consolidated with use of therapeutic CPAP throughout, whereas on the other night, CPAP was reduced only in REM sleep, allowing REM OSA to recur. REM disruption via this method caused REM sleep reduction and significantly fragmented any remaining REM sleep without affecting total sleep time, sleep efficiency, or slow-wave sleep. We observed improvements in maze performance after a night of normal sleep that were significantly attenuated after a night of REM disruption without changes in psychomotor vigilance. Furthermore, the improvement in maze completion time significantly positively correlated with the mean REM run duration across both sleep conditions. In conclusion, we demonstrate a novel role for REM sleep in human memory formation and highlight a significant cognitive consequence of OSA. Copyright © 2014 the authors 0270-6474/14/3414571-07$15.00/0.

  9. Rapid-Eye-Movement-Sleep (REM Associated Enhancement of Working Memory Performance after a Daytime Nap.

    Directory of Open Access Journals (Sweden)

    Esther Yuet Ying Lau

    Full Text Available The main objective was to study the impact of a daytime sleep opportunity on working memory and the mechanism behind such impact. This study adopted an experimental design in a sleep research laboratory. Eighty healthy college students (Age:17-23, 36 males were randomized to either have a polysomnography-monitored daytime sleep opportunity (Nap-group, n=40 or stay awake (Wake-group, n=40 between the two assessment sessions. All participants completed a sleep diary and wore an actigraph-watch for 5 days before and one day after the assessment sessions. They completed the state-measurement of sleepiness and affect, in addition to a psychomotor vigilance test and a working memory task before and after the nap/wake sessions. The two groups did not differ in their sleep characteristics prior to and after the lab visit. The Nap-group had higher accuracy on the working memory task, fewer lapses on the psychomotor vigilance test and lower state-sleepiness than the Wake-group. Within the Nap-group, working memory accuracy was positively correlated with duration of rapid eye movement sleep (REM and total sleep time during the nap. Our findings suggested that "sleep gain" during a daytime sleep opportunity had significant positive impact on working memory performance, without affecting subsequent nighttime sleep in young adult, and such impact was associated with the duration of REM. While REM abnormality has long been noted in pathological conditions (e.g. depression, which are also presented with cognitive dysfunctions (e.g. working memory deficits, this was the first evidence showing working memory enhancement associated with REM in daytime napping in college students, who likely had habitual short sleep duration but were otherwise generally healthy.

  10. Rapid-Eye-Movement-Sleep (REM) Associated Enhancement of Working Memory Performance after a Daytime Nap

    Science.gov (United States)

    Lau, Kristy Nga Ting; Hui, Florence Wai Ying; Tseng, Chia-huei

    2015-01-01

    The main objective was to study the impact of a daytime sleep opportunity on working memory and the mechanism behind such impact. This study adopted an experimental design in a sleep research laboratory. Eighty healthy college students (Age:17-23, 36 males) were randomized to either have a polysomnography-monitored daytime sleep opportunity (Nap-group, n=40) or stay awake (Wake-group, n=40) between the two assessment sessions. All participants completed a sleep diary and wore an actigraph-watch for 5 days before and one day after the assessment sessions. They completed the state-measurement of sleepiness and affect, in addition to a psychomotor vigilance test and a working memory task before and after the nap/wake sessions. The two groups did not differ in their sleep characteristics prior to and after the lab visit. The Nap-group had higher accuracy on the working memory task, fewer lapses on the psychomotor vigilance test and lower state-sleepiness than the Wake-group. Within the Nap-group, working memory accuracy was positively correlated with duration of rapid eye movement sleep (REM) and total sleep time during the nap. Our findings suggested that “sleep gain” during a daytime sleep opportunity had significant positive impact on working memory performance, without affecting subsequent nighttime sleep in young adult, and such impact was associated with the duration of REM. While REM abnormality has long been noted in pathological conditions (e.g. depression), which are also presented with cognitive dysfunctions (e.g. working memory deficits), this was the first evidence showing working memory enhancement associated with REM in daytime napping in college students, who likely had habitual short sleep duration but were otherwise generally healthy. PMID:25970511

  11. Pacing the phasing of leg and arm movements in breaststroke swimming to minimize intra-cyclic velocity fluctuations

    NARCIS (Netherlands)

    Van Houwelingen, Josje; Roerdink, Melvyn; Huibers, Alja V.; Evers, Lotte L.W.; Beek, Peter J.

    2017-01-01

    In swimming propelling efficiency is partly determined by intra-cyclic velocity fluctuations. The higher these fluctuations are at a given average swimming velocity, the less efficient is the propulsion. This study explored whether the leg-arm coordination (i.e. phase relation ϕ) within the

  12. Influence of Gravity Compensation on Muscle Activation Patterns During Different Temporal Phases of Arm Movements of Stroke Patients

    NARCIS (Netherlands)

    Prange, Grada Berendina; Jannink, M.J.A.; Stienen, Arno; van der Kooij, Herman; IJzerman, Maarten Joost; Hermens, Hermanus J.

    2009-01-01

    Background. Arm support to help compensate for the effects of gravity may improve functional use of the shoulder and elbow during therapy after stroke, but gravity compensation may alter motor control. Objective. To obtain quantitative information on how gravity compensation influences muscle

  13. Rapid risk household screening by neonatal arm circumference: results from a cohort study in rural Burkina Faso.

    Science.gov (United States)

    Benzler, J; Sauerborn, R

    1998-12-01

    Neonatal arm circumference (NAC) and other attributes of the newborn and its household were analysed as potential predictors of child death in a cohort of 1367 newborn children representing the majority of births in a rural area of Burkina Faso from 1992 to 1994. During 3872 person years observed 264 children died, resulting in an average mortality rate of 6.8% per year. 90 mm was chosen as the best cut-off to differentiate low NAC associated with high mortality from normal NAC. The hazard ratio of children with low NAC (15.7%) compared to others was 1.7 (P cash crop production. We propose a simple risk score for rapid household screening in rural Burkina Faso and comparable settings elsewhere for identifying households at risk of experiencing child death. As much of the other variables' contribution to the explanation of survival pattern is absorbed by NAC in more parsimonious models, even simpler screening strategies based on NAC make sense. In the study area risk households will be offered periodical home visits by the local nurse promoting immunization, treatment of illness and strengthening the mothers' competence to recognize and manage frequent health problems of their children as part of a 'Shared Care' concept.

  14. Inverse biomimetics: how robots can help to verify concepts concerning sensorimotor control of human arm and leg movements.

    Science.gov (United States)

    Kalveram, Karl Theodor; Seyfarth, André

    2009-01-01

    Simulation test, hardware test and behavioral comparison test are proposed to experimentally verify whether a technical control concept for limb movements is logically precise, physically sound, and biologically relevant. Thereby, robot test-beds may play an integral part by mimicking functional limb movements. The procedure is exemplarily demonstrated for human aiming movements with the forearm: when comparing competitive control concepts, these movements are described best by a spring-like operating muscular-skeletal device which is assisted by feedforward control through an inverse internal model of the limb--without regress to a forward model of the limb. In a perspective on hopping, the concept of exploitive control is addressed, and its comparison to concepts derived from classical control theory advised.

  15. Movement of Sediment Associated With Lowered Reservoir Levels in the Rio La Venta Arm of the Presa Netzahualcoyotl, Chiapas, Mexico

    Science.gov (United States)

    Hilton, S.; de La Fuente, J.; Lisle, T. E.; Velasquez, J.; Allison, B.; Olson, B.; Quinones, R.

    2003-12-01

    A joint sedimentation study is currently underway at the Netzahualcoyotl reservoir in Chiapas, Mexico, involving the Comision Nacional de Areas Naturales Protegidas (CONANP) of the Secretaria de Medio Ambiente y Recursos Naturales and the USDA Forest Service. The reservoir is adjacent to the Reserva de la Biosfera, Selva El Ocote, administered by CONANP. Ongoing research is intended to provide watershed and reservoir managers with strategies to protect the resources of Rio La Venta canyon. The Rio La Venta arm of the reservoir is incised into karst terrain, with near-vertical limestone walls up to 300 meters high. The canyon is fed by two rivers, Rio La Selva and Rio Negro, and is surrounded by pristine tropical forest. The majority of the clastic sediment (predominantly sand and fine gravel) entering the reservoir originates in the headwaters of the two rivers which are underlain by weathered and dissected granitic terrain. Rapid sedimentation of the partially inundated canyon poses a threat to the aquatic ecosystem, as well as to recreational resources. Longitudinal and transverse profiles were surveyed in the inundated canyon in March of 2002 and repeated in April of 2003 when the reservoir level was 15 meters lower. The 2002 longitudinal profile shows an inflection from a slope of 0.0017 to one of 0.0075 at 7.2 km downstream of the mouth of Rio Negro. In 2003, the two slopes remained the same, but the bed lowered about 5 meters and the inflection point moved downstream about 2.3 km. We calculated that reservoir lowering in 2003 allowed the transport of 2.5 million cubic meters of sand further out into the reservoir. This volume is more than the average annual rate of filling up to the 2002 level since 1984 when sedimentation was not as advanced (De la Fuente et al., 2002), which was calculated disregarding loss of sediment to the main reservoir. Field observations at late dry season low flows in 2003 revealed active transport of sand and pebbles and formation

  16. Non-Rapid Eye Movement Sleep Parasomnias and Migraine: A Role of Orexinergic Projections

    Directory of Open Access Journals (Sweden)

    Antonietta Messina

    2018-02-01

    Full Text Available IntroductionSleep and migraine share a common pathophysiological substrate, although the underlying mechanisms are unknown. The serotonergic and orexinergic systems are both involved in the regulation of sleep/wake cycle, and numerous studies show that both are involved in the migraine etiopathogenesis. These two systems are anatomically and functionally interconnected. Our hypothesis is that in migraine a dysfunction of orexinergic projections on the median raphe (MR nuclei, interfering with serotonergic regulation, may cause Non-Rapid Eye Movement parasomnias, such as somnambulism.Hypothesis/theoryActing on the serotonergic neurons of the raphe nuclei, the dysfunction of orexinergic neurons would lead to a higher release of serotonin. The activation of serotonergic receptors located on the walls of large cerebral vessels would lead to abnormal vasodilatation and consequently increase transmural pressure. This process could activate the trigeminal nerve terminals that innervate vascular walls. As a consequence, there is activation of sensory nerve endings at the level of hard vessels in the meninges, with release of pro-inflammatory peptides (e.g., substance P and CGRP. Within this hypothetical frame, the released serotonin could also interact with trigeminovascular afferents to activate and/or facilitate the release of the neuropeptide at the level of the trigeminal ganglion. The dysregulation of the physiological negative feedback of serotonin on the orexinergic neurons, in turn, would contribute to an alteration of the whole system, altering the sleep–wake cycle.ConclusionSerotonergic neurons of the MR nuclei receive an excitatory input from hypothalamic orexin/hypocretin neurons and reciprocally inhibit orexin/hypocretin neurons through the serotonin 1A receptor (or 5-HT1A receptor. Considering this complex system, if there is an alteration it may facilitate the pathophysiological mechanisms involved in the migraine, while it may produce

  17. Rapid eye movement sleep deprivation induces an increase in acetylcholinesterase activity in discrete rat brain regions

    Directory of Open Access Journals (Sweden)

    Benedito M.A.C.

    2001-01-01

    Full Text Available Some upper brainstem cholinergic neurons (pedunculopontine and laterodorsal tegmental nuclei are involved in the generation of rapid eye movement (REM sleep and project rostrally to the thalamus and caudally to the medulla oblongata. A previous report showed that 96 h of REM sleep deprivation in rats induced an increase in the activity of brainstem acetylcholinesterase (Achase, the enzyme which inactivates acetylcholine (Ach in the synaptic cleft. There was no change in the enzyme's activity in the whole brain and cerebrum. The components of the cholinergic synaptic endings (for example, Achase are not uniformly distributed throughout the discrete regions of the brain. In order to detect possible regional changes we measured Achase activity in several discrete rat brain regions (medulla oblongata, pons, thalamus, striatum, hippocampus and cerebral cortex after 96 h of REM sleep deprivation. Naive adult male Wistar rats were deprived of REM sleep using the flower-pot technique, while control rats were left in their home cages. Total, membrane-bound and soluble Achase activities (nmol of thiocholine formed min-1 mg protein-1 were assayed photometrically. The results (mean ± SD obtained showed a statistically significant (Student t-test increase in total Achase activity in the pons (control: 147.8 ± 12.8, REM sleep-deprived: 169.3 ± 17.4, N = 6 for both groups, P<0.025 and thalamus (control: 167.4 ± 29.0, REM sleep-deprived: 191.9 ± 15.4, N = 6 for both groups, P<0.05. Increases in membrane-bound Achase activity in the pons (control: 171.0 ± 14.7, REM sleep-deprived: 189.5 ± 19.5, N = 6 for both groups, P<0.05 and soluble enzyme activity in the medulla oblongata (control: 147.6 ± 16.3, REM sleep-deprived: 163.8 ± 8.3, N = 6 for both groups, P<0.05 were also observed. There were no statistically significant differences in the enzyme's activity in the other brain regions assayed. The present findings show that the increase in Achase activity

  18. STOP-Bang Questionnaire in Patients with Rapid Eye Movement Sleep Behavior Disorder

    Directory of Open Access Journals (Sweden)

    Ki-Hwan Ji

    2017-12-01

    Full Text Available Background and Objective The snoring, tiredness, observed apnea, and high blood pressure– body mass index, age, neck circumference, and gender (STOP-Bang questionnaire is known as a simple but useful tool for the diagnosis of high-risk obstructive sleep apnea (OSA. However, the utility of STOP-Bang questionnaire in rapid eye movement (REM sleep behavior disorder (RBD populations is not validated. This study aimed to determine the diagnostic value of the STOP-Bang questionnaire in patients with RBD at high risk for OSA. Methods We collected data from 65 consecutive patients who were diagnosed with RBD in a tertiary sleep center (20 women; mean age, 64.3 ± 12.5 years. All the patients visited sleep center with complaints of abnormal behavior during sleep, and underwent testing with STOP-Bang questionnaire and polysomnography. The diagnosis of RBD was based on the International Classification of Sleep Disorders, second edition. We diagnosed OSA when apnea-hypopnea index (AHI was at least 5/h. The receiver operating characteristic (ROC curves were plotted. Results The mean AHI was 18.2 ± 16.5/h, and 75.4% (n = 49 had an AHI ≥ 5. The STOP-Bang (threshold ≥ 3 identified 70.7% of patients as high risk for OSA, and sensitivity, specificity, positive and negative predictive values were 81.6, 62.5, 87, and 52.6%, respectively. The area under the ROC curve (AUC was 0.79 (p < 0.001. The STOP (threshold ≥ 2 identified 70.7% of patients at high risk for OSA, and sensitivity, specificity, positive and negative predictive values were 75.5, 87.5, 94.9, and 53.8%, respectively. The AUC was 0.86 (p < 0.001. A pairwise comparison of ROC curve between STOP-Bang and STOP was insignificant (p = 0.145. Conclusions In RBD population, the STOP-Bang or STOP questionnaire is a useful screening tool to identify patients at high risk for OSA.

  19. A Hidden Markov Movement Model for rapidly identifying behavioral states from animal tracks

    DEFF Research Database (Denmark)

    Whoriskey, Kim; Auger-Méthé, Marie; Albertsen, Christoffer Moesgaard

    2017-01-01

    by fitting it to real tracks from a grey seal, lake trout, and blue shark, as well as to simulated data. 4. The HMMM is a fast and reliable tool for making meaningful inference from animal movement data that is ideally suited for ecologists who want to use the popular DCRWS implementation for highly accurate......1. Electronic telemetry is frequently used to document animal movement through time. Methods that can identify underlying behaviors driving specific movement patterns can help us understand how and why animals use available space, thereby aiding conservation and management efforts. For aquatic...... animal tracking data with significant measurement error, a Bayesian state-space model called the first-Difference Correlated Random Walk with Switching (DCRWS) has often been used for this purpose. However, for aquatic animals, highly accurate tracking data of animal movement are now becoming more common...

  20. Right-Left Approach and Reaching Arm Movements of 4-Month Infants in Free and Constrained Conditions

    Science.gov (United States)

    Morange-Majoux, Francoise; Dellatolas, Georges

    2010-01-01

    Recent theories on the evolution of language (e.g. Corballis, 2009) emphazise the interest of early manifestations of manual laterality and manual specialization in human infants. In the present study, left- and right-hand movements towards a midline object were observed in 24 infants aged 4 months in a constrained condition, in which the hands…

  1. Nocturnal rapid eye movement sleep latency for identifying patients with narcolepsy/hypocretin deficiency.

    Science.gov (United States)

    Andlauer, Olivier; Moore, Hyatt; Jouhier, Laura; Drake, Christopher; Peppard, Paul E; Han, Fang; Hong, Seung-Chul; Poli, Francesca; Plazzi, Giuseppe; O'Hara, Ruth; Haffen, Emmanuel; Roth, Thomas; Young, Terry; Mignot, Emmanuel

    2013-07-01

    Narcolepsy, a disorder associated with HLA-DQB1*06:02 and caused by hypocretin (orexin) deficiency, is diagnosed using the Multiple Sleep Latency Test (MSLT) following nocturnal polysomnography (NPSG). In many patients, a short rapid eye movement sleep latency (REML) during the NPSG is also observed but not used diagnostically. To determine diagnostic accuracy and clinical utility of nocturnal REML measures in narcolepsy/hypocretin deficiency. Observational study using receiver operating characteristic curves for NPSG REML and MSLT findings (sleep studies performed between May 1976 and September 2011 at university medical centers in the United States, China, Korea, and Europe) to determine optimal diagnostic cutoffs for narcolepsy/hypocretin deficiency compared with different samples: controls, patients with other sleep disorders, patients with other hypersomnias, and patients with narcolepsy with normal hypocretin levels. Increasingly stringent comparisons were made. In a first comparison, 516 age- and sex-matched patients with narcolepsy/hypocretin deficiency were selected from 1749 patients and compared with 516 controls. In a second comparison, 749 successive patients undergoing sleep evaluation for any sleep disorders (low pretest probability for narcolepsy) were compared within groups by final diagnosis of narcolepsy/hypocretin deficiency. In the third comparison, 254 patients with a high pretest probability of having narcolepsy were compared within group by their final diagnosis. Finally, 118 patients with narcolepsy/hypocretin deficiency were compared with 118 age- and sex-matched patients with a diagnosis of narcolepsy but with normal hypocretin levels. Sensitivity and specificity of NPSG REML and MSLT as diagnostic tests for narcolepsy/hypocretin deficiency. This diagnosis was defined as narcolepsy associated with cataplexy plus HLA-DQB1*06:02 positivity (no cerebrospinal fluid hypocretin-1 results available) or narcolepsy with documented low (≤ 110 pg

  2. Using Wearable Sensors and Machine Learning Models to Separate Functional Upper Extremity Use From Walking-Associated Arm Movements.

    Science.gov (United States)

    McLeod, Adam; Bochniewicz, Elaine M; Lum, Peter S; Holley, Rahsaan J; Emmer, Geoff; Dromerick, Alexander W

    2016-02-01

    To improve measurement of upper extremity (UE) use in the community by evaluating the feasibility of using body-worn sensor data and machine learning models to distinguish productive prehensile and bimanual UE activity use from extraneous movements associated with walking. Comparison of machine learning classification models with criterion standard of manually scored videos of performance in UE prosthesis users. Rehabilitation hospital training apartment. Convenience sample of UE prosthesis users (n=5) and controls (n=13) similar in age and hand dominance (N=18). Participants were filmed executing a series of functional activities; a trained observer annotated each frame to indicate either UE movement directed at functional activity or walking. Synchronized data from an inertial sensor attached to the dominant wrist were similarly classified as indicating either a functional use or walking. These data were used to train 3 classification models to predict the functional versus walking state given the associated sensor information. Models were trained over 4 trials: on UE amputees and controls and both within subject and across subject. Model performance was also examined with and without preprocessing (centering) in the across-subject trials. Percent correct classification. With the exception of the amputee/across-subject trial, at least 1 model classified >95% of test data correctly for all trial types. The top performer in the amputee/across-subject trial classified 85% of test examples correctly. We have demonstrated that computationally lightweight classification models can use inertial data collected from wrist-worn sensors to reliably distinguish prosthetic UE movements during functional use from walking-associated movement. This approach has promise in objectively measuring real-world UE use of prosthetic limbs and may be helpful in clinical trials and in measuring response to treatment of other UE pathologies. Copyright © 2016 American Congress of

  3. Dealing with the Empty Vehicle Movements in Personal Rapid Transit System with Batteries Constraints in a Dynamic Context

    Directory of Open Access Journals (Sweden)

    Ezzeddine Fatnassi

    2017-01-01

    Full Text Available The Personal Rapid Transit is a new emergent transportation tool. It relies on using a set of small driverless electric vehicles to transport people on demand. Because of the specific on-demand characteristic of the Personal Rapid Transit system, many Personal Rapid Transit vehicles would move empty which results in a high level of wasted transportation capacity. This is enhanced while using Personal Rapid Transit vehicles with limited electric battery capacity. This paper deals with this problem in a real time context while minimizing the set of empty vehicle movements. First, a mathematical formulation to benchmark waiting time of passengers in Personal Rapid Transit systems is proposed. Then, a simulation model that captures the main features of the Personal Rapid Transit system is developed. A decision support system which integrates several real time solution strategies as well as a simulation module is proposed. Our dispatching strategies are evaluated and compared based on our simulation model. The efficiency of our method is tested through extensive test studies.

  4. Impact forces cannot explain the one-target advantage in rapid aimed hand movements

    NARCIS (Netherlands)

    Biegstraaten, Marianne; Smeets, Jeroen B J; Brenner, Eli

    A pointing movement is executed faster when a subject is allowed to stop at the first target than when the subject has to proceed to a second target ("one-target advantage"). Our hypothesis was that this is because the impact at the target helps to stop the finger when the finger does not have to

  5. Brain-state dependent robotic reaching movement with a multi-joint arm exoskeleton: combining brain-machine interfacing and robotic rehabilitation

    Directory of Open Access Journals (Sweden)

    Daniel eBrauchle

    2015-10-01

    Full Text Available While robot-assisted arm and hand training after stroke allows for intensive task-oriented practice, it has provided only limited additional benefit over dose-matched physiotherapy up to now. These rehabilitation devices are possibly too supportive during the exercises. Neurophysiological signals might be one way of avoiding slacking and providing robotic support only when the brain is particularly responsive to peripheral input.We tested the feasibility of three-dimensional robotic assistance for reach-to-grasp movements with a multi-joint exoskeleton during motor imagery-related desynchronization of sensorimotor oscillations in the β-band only. We also registered task-related network changes of cortical functional connectivity by electroencephalography via the imaginary part of the coherence function.Healthy subjects and stroke survivors showed similar patterns – but different aptitudes – of controlling the robotic movement. All participants in this pilot study with nine healthy subjects and two stroke patients achieved their maximum performance during the early stages of the task. Robotic control was significantly higher and less variable when proprioceptive feedback was provided in addition to visual feedback, i.e. when the orthosis was actually attached to the subject’s arm during the task. A distributed cortical network of task-related coherent activity in the θ-band showed significant differences between healthy subjects and stroke patients as well as between early and late periods of the task.Brain-robot interfaces may successfully link three-dimensional robotic training to the participants’ efforts and allow for task-oriented practice of activities of daily living with a physiologically controlled multi-joint exoskeleton. Changes of cortical physiology during the task might also help to make subject-specific adjustments of task difficulty and guide adjunct interventions to facilitate motor learning for functional restoration.

  6. A crossover pilot study evaluating the functional outcomes of two different types of robotic movement training in chronic stroke survivors using the arm exoskeleton BONES.

    Science.gov (United States)

    Milot, Marie-Hélène; Spencer, Steven J; Chan, Vicky; Allington, James P; Klein, Julius; Chou, Cathy; Bobrow, James E; Cramer, Steven C; Reinkensmeyer, David J

    2013-12-19

    To date, the limited degrees of freedom (DOF) of most robotic training devices hinders them from providing functional training following stroke. We developed a 6-DOF exoskeleton ("BONES") that allows movement of the upper limb to assist in rehabilitation. The objectives of this pilot study were to evaluate the impact of training with BONES on function of the affected upper limb, and to assess whether multijoint functional robotic training would translate into greater gains in arm function than single joint robotic training also conducted with BONES. Twenty subjects with mild to moderate chronic stroke participated in this crossover study. Each subject experienced multijoint functional training and single joint training three sessions per week, for four weeks, with the order of presentation randomized. The primary outcome measure was the change in Box and Block Test (BBT). The secondary outcome measures were the changes in Fugl-Meyer Arm Motor Scale (FMA), Wolf Motor Function Test (WMFT), Motor Activity Log (MAL), and quantitative measures of strength and speed of reaching. These measures were assessed at baseline, after each training period, and at a 3-month follow-up evaluation session. Training with the robotic exoskeleton resulted in significant improvements in the BBT, FMA, WMFT, MAL, shoulder and elbow strength, and reaching speed (p robotic training programs. However, for the BBT, WMFT and MAL, inequality of carryover effects were noted; subsequent analysis on the change in score between the baseline and first period of training again revealed no difference in the gains obtained between the types of training. Training with the 6 DOF arm exoskeleton improved motor function after chronic stroke, challenging the idea that robotic therapy is only useful for impairment reduction. The pilot results presented here also suggest that multijoint functional robotic training is not decisively superior to single joint robotic training. This challenges the idea that

  7. Study on the relation of brain functional connectivity to movement disorders and cognitive impairment in patients with rapid eye movement sleep behavior disorder

    Directory of Open Access Journals (Sweden)

    Hong-ju ZHANG

    2017-09-01

    Full Text Available Objective To explore the relation between abnormal functional connectivity of substantia nigra and impairment of movement and cognition in patients with rapid eye movement sleep behavior disorder (RBD. Methods A total of 22 subjects, including 14 patients with RBD and 8 sex, age, education-matched healthy controls, were enrolled in this study according to international diagnostic criteria. Unified Parkinson's Disease Rating Scale Ⅲ (UPDRS Ⅲ and Hoehn-Yahr Stage were used to evaluate motor function. Digit Ordering Test - Attention (DOT - A, Symbol Digit Modalities Test (SDMT, Stroop Color-Word Test (SCWT, Trail Making Test (TMT, Rey-Osterrieth Complex Figure Test (ROCFT, Clock Drawing Test (CDT, Boston Naming Test (BNT and Auditory Verbal Learning Test (AVLT were used to evaluate cognitive function. The functional connectivity from left and right substantia nigra to brain region were examined. Results There were no statistical differences of UPDRSⅢ and Hoehn?Yahr Stage between 2 groups (P > 0.05, for all. In comparison with control group, SDMT (P = 0.001, ROCFT-copy (P = 0.013 and AVLT-N2 (P = 0.032 were significantly lower, while TMT-B test was significantly higher (P =0.005 in RBD group. Compared with control group, the functional connectivity of right substantia nigra to left precentral gyrus (P < 0.005 and right angular gyrus (P < 0.005 were all decreased in RBD group. Conclusions The results suggest that cognitive impairment occurs earlier than movement disorders in RBD, and there are abnormal functional connectivity from right substantia nigra to left precentral gyrus and right angular gyrus, proving that abnormal functional connectivity is the base of behavior disorders in RBD. DOI: 10.3969/j.issn.1672-6731.2017.09.005

  8. A rapid phenol toxicity test based on photosynthesis and movement of the freshwater flagellate, Euglena agilis Carter

    International Nuclear Information System (INIS)

    Kottuparambil, Sreejith; Kim, Youn-Jung; Choi, Hoon; Kim, Mi-Sung; Park, Areum; Park, Jihae; Shin, Woongghi; Han, Taejun

    2014-01-01

    Highlights: • Rapid phenol toxicity tests (1 h) were developed based on Chl a fluorescence and the movement parameters of Euglena agilis. • Phenol significantly reduced F v /F m of PS II and rETRmax with EC50 values of 8.94 and 4.67 mM, respectively. • Among the movement parameters tested, velocity was the most sensitive biomarker with an EC50 of 3.17 mM. • The EC50 values for F v /F m , motility, and velocity appear to overlap the environmental permissible levels of phenol. - Abstract: Phenol, a monosubstituted aromatic hydrocarbon with various commercial uses, is a major organic constituent in industrial wastewaters. The ecotoxic action of phenol for aquatic environment is well known. In this study, rapid phenol toxicity tests (1 h) were developed based on chlorophyll a (Chl a) fluorescence and the movement parameters of the freshwater flagellate, Euglena agilis Carter. Phenol significantly reduced the maximum quantum yield (F v /F m ) of photosystem II (PS II) and the maximum photosynthetic electron transport rate (rETR max ) with median effective concentration (EC 50 ) values of 8.94 and 4.67 mM, respectively. Phenol reduced the motility and triggered change in the swimming velocity of the test organism. Among the parameters tested, velocity was the most sensitive biomarker with an EC 50 of 3.17 mM. The EC 50 values for F v /F m , motility, and velocity appear to overlap the permitted levels of phenol. In conclusion, the photosynthesis and movement of E. agilis can be fast and sensitive risk assessment parameters for the evaluation of phenol toxicity in municipal and industrial effluents

  9. A rapid phenol toxicity test based on photosynthesis and movement of the freshwater flagellate, Euglena agilis Carter

    Energy Technology Data Exchange (ETDEWEB)

    Kottuparambil, Sreejith [Institute of Green Environmental Research Center, Incheon National University, Incheon 406 840 (Korea, Republic of); Kim, Youn-Jung [Institute of Green Environmental Research Center, Incheon National University, Incheon 406 840 (Korea, Republic of); Department of Marine Science, Incheon National University, Incheon 406 840 (Korea, Republic of); Green-Pioneer (Ltd.), Incheon National University, Incheon 406 840 (Korea, Republic of); Choi, Hoon; Kim, Mi-Sung; Park, Areum; Park, Jihae [Institute of Green Environmental Research Center, Incheon National University, Incheon 406 840 (Korea, Republic of); Shin, Woongghi [Department of Biology, Chungnam University, Daejeon 306 764 (Korea, Republic of); Han, Taejun, E-mail: hanalgae@hanmail.net [Institute of Green Environmental Research Center, Incheon National University, Incheon 406 840 (Korea, Republic of); Department of Marine Science, Incheon National University, Incheon 406 840 (Korea, Republic of); Green-Pioneer (Ltd.), Incheon National University, Incheon 406 840 (Korea, Republic of)

    2014-10-15

    Highlights: • Rapid phenol toxicity tests (1 h) were developed based on Chl a fluorescence and the movement parameters of Euglena agilis. • Phenol significantly reduced F{sub v}/F{sub m} of PS II and rETRmax with EC50 values of 8.94 and 4.67 mM, respectively. • Among the movement parameters tested, velocity was the most sensitive biomarker with an EC50 of 3.17 mM. • The EC50 values for F{sub v}/F{sub m}, motility, and velocity appear to overlap the environmental permissible levels of phenol. - Abstract: Phenol, a monosubstituted aromatic hydrocarbon with various commercial uses, is a major organic constituent in industrial wastewaters. The ecotoxic action of phenol for aquatic environment is well known. In this study, rapid phenol toxicity tests (1 h) were developed based on chlorophyll a (Chl a) fluorescence and the movement parameters of the freshwater flagellate, Euglena agilis Carter. Phenol significantly reduced the maximum quantum yield (F{sub v}/F{sub m}) of photosystem II (PS II) and the maximum photosynthetic electron transport rate (rETR{sub max}) with median effective concentration (EC{sub 50}) values of 8.94 and 4.67 mM, respectively. Phenol reduced the motility and triggered change in the swimming velocity of the test organism. Among the parameters tested, velocity was the most sensitive biomarker with an EC{sub 50} of 3.17 mM. The EC{sub 50} values for F{sub v}/F{sub m}, motility, and velocity appear to overlap the permitted levels of phenol. In conclusion, the photosynthesis and movement of E. agilis can be fast and sensitive risk assessment parameters for the evaluation of phenol toxicity in municipal and industrial effluents.

  10. Effects of a cognitive dual task on variability and local dynamic stability in sustained repetitive arm movements using principal component analysis: a pilot study.

    Science.gov (United States)

    Longo, Alessia; Federolf, Peter; Haid, Thomas; Meulenbroek, Ruud

    2018-06-01

    In many daily jobs, repetitive arm movements are performed for extended periods of time under continuous cognitive demands. Even highly monotonous tasks exhibit an inherent motor variability and subtle fluctuations in movement stability. Variability and stability are different aspects of system dynamics, whose magnitude may be further affected by a cognitive load. Thus, the aim of the study was to explore and compare the effects of a cognitive dual task on the variability and local dynamic stability in a repetitive bimanual task. Thirteen healthy volunteers performed the repetitive motor task with and without a concurrent cognitive task of counting aloud backwards in multiples of three. Upper-body 3D kinematics were collected and postural reconfigurations-the variability related to the volunteer's postural change-were determined through a principal component analysis-based procedure. Subsequently, the most salient component was selected for the analysis of (1) cycle-to-cycle spatial and temporal variability, and (2) local dynamic stability as reflected by the largest Lyapunov exponent. Finally, end-point variability was evaluated as a control measure. The dual cognitive task proved to increase the temporal variability and reduce the local dynamic stability, marginally decrease endpoint variability, and substantially lower the incidence of postural reconfigurations. Particularly, the latter effect is considered to be relevant for the prevention of work-related musculoskeletal disorders since reduced variability in sustained repetitive tasks might increase the risk of overuse injuries.

  11. An exploratory investigation on the use of closed-loop electrical stimulation to assist individuals with stroke to perform fine movements with their hemiparetic arm

    Directory of Open Access Journals (Sweden)

    Brian eLew

    2016-03-01

    Full Text Available Stroke is the leading cause of upper limb impairments resulting in disability. Modern rehabilitation includes training with robotic exoskeletons and functional electrical stimulation (FES. However, there is a gap in knowledge to define the detailed use of FES in stroke rehabilitation. In this paper, we explore applying closed-loop FES to the upper extremities (UE of healthy volunteers and individuals with a hemiparetic arm resulting from stroke. We used a set of gyroscopes to monitor arm movements and used a non-linear controller, namely the robust integral of the sign of the error (RISE, to assess the viability of controlling FES in closed-loop. Further, we explored the application of closed-loop FES in improving functional tasks performed by individuals with stroke. Four healthy individuals of ages 27 to 32 years old and five individuals with stroke of ages 61 to 83 years old participated in this study. We used the Rehastim FES unit (Hasomed Ltd. with real-time modulation of pulse width and amplitude. Both healthy and stroke individuals were tested in RISE controlled single and multi-joint upper limb motions following first a sinusoidal trajectory. Individuals with stroke were also asked to perform the following functional tasks: picking up a basket, picking and placing an object on a table, cutting a pizza, pulling back a chair, eating with a spoon, as well as using a stapler and grasping a pen. Healthy individuals were instructed to keep their arm relaxed during the experiment. Most individuals with stroke were able to follow the sinusoid trajectories with their arm joints under the sole excitation of the closed-loop controlled FES. One individual with stroke who was unable to perform any of the functional tasks independently, succeeded in completing all the tasks when FES was used. Three other individuals with stroke, who were unable to complete a few tasks independently, completed some of them when FES was used. The remaining stroke

  12. Dopamine agonist suppression of rapid-eye-movement sleep is secondary to sleep suppression mediated via limbic structures

    International Nuclear Information System (INIS)

    Miletich, R.S.

    1985-01-01

    The effects of pergolide, a direct dopamine receptor agonist, on sleep and wakefulness, motor behavior and 3 H-spiperone specific binding in limbic structures and striatum in rats was studied. The results show that pergolide induced a biphasic dose effect, with high doses increasing wakefulness and suppressing sleep while low dose decreased wakefulness, but increased sleep. It was shown that pergolide-induced sleep suppression was blocked by α-glupenthixol and pimozide, two dopamine receptor antagonists. It was further shown that pergolide merely delayed the rebound resulting from rapid-eye-movement (REM) sleep deprivation, that dopamine receptors stimulation had no direct effect on the period, phase or amplitude of the circadian rhythm of REM sleep propensity and that there was no alteration in the coupling of REM sleep episodes with S 2 episodes. Rapid-eye-movement sleep deprivation resulted in increased sensitivity to the pergolide-induced wakefulness stimulation and sleep suppression and pergolide-induced motor behaviors of locomotion and head bobbing. 3 H-spiperone specific binding to dopamine receptors was shown to be altered by REM sleep deprivation in the subcortical limbic structures. It is concluded that the REM sleep suppressing action of dopamine receptor stimulation is secondary to sleep suppression per se and not secondary to a unique effect on the REM sleep. Further, it is suggested that the wakefulness stimulating action of dopamine receptor agonists is mediated by activation of the dopamine receptors in the terminal areas of the mesolimbocortical dopamine projection system

  13. Shorter duration of non-rapid eye movement sleep slow waves in EphA4 knockout mice.

    Science.gov (United States)

    Freyburger, Marlène; Poirier, Gaétan; Carrier, Julie; Mongrain, Valérie

    2017-10-01

    Slow waves occurring during non-rapid eye movement sleep have been associated with neurobehavioural performance and memory. In addition, the duration of previous wakefulness and sleep impacts characteristics of these slow waves. However, molecular mechanisms regulating the dynamics of slow-wave characteristics remain poorly understood. The EphA4 receptor regulates glutamatergic transmission and synaptic plasticity, which have both been linked to sleep slow waves. To investigate if EphA4 regulates slow-wave characteristics during non-rapid eye movement sleep, we compared individual parameters of slow waves between EphA4 knockout mice and wild-type littermates under baseline conditions and after a 6-h sleep deprivation. We observed that, compared with wild-type mice, knockout mice display a shorter duration of positive and negative phases of slow waves under baseline conditions and after sleep deprivation. However, the mutation did not change slow-wave density, amplitude and slope, and did not affect the sleep deprivation-dependent changes in slow-wave characteristics, suggesting that EphA4 is not involved in the response to elevated sleep pressure. Our present findings suggest a role for EphA4 in shaping cortical oscillations during sleep that is independent from sleep need. © 2017 European Sleep Research Society.

  14. Rapid learning of magnetic compass direction by C57BL/6 mice in a 4-armed 'plus' water maze.

    Directory of Open Access Journals (Sweden)

    John B Phillips

    Full Text Available Magnetoreception has been demonstrated in all five vertebrate classes. In rodents, nest building experiments have shown the use of magnetic cues by two families of molerats, Siberian hamsters and C57BL/6 mice. However, assays widely used to study rodent spatial cognition (e.g. water maze, radial arm maze have failed to provide evidence for the use of magnetic cues. Here we show that C57BL/6 mice can learn the magnetic direction of a submerged platform in a 4-armed (plus water maze. Naïve mice were given two brief training trials. In each trial, a mouse was confined to one arm of the maze with the submerged platform at the outer end in a predetermined alignment relative to magnetic north. Between trials, the training arm and magnetic field were rotated by 180(° so that the mouse had to swim in the same magnetic direction to reach the submerged platform. The directional preference of each mouse was tested once in one of four magnetic field alignments by releasing it at the center of the maze with access to all four arms. Equal numbers of responses were obtained from mice tested in the four symmetrical magnetic field alignments. Findings show that two training trials are sufficient for mice to learn the magnetic direction of the submerged platform in a plus water maze. The success of these experiments may be explained by: (1 absence of alternative directional cues (2, rotation of magnetic field alignment, and (3 electromagnetic shielding to minimize radio frequency interference that has been shown to interfere with magnetic compass orientation of birds. These findings confirm that mice have a well-developed magnetic compass, and give further impetus to the question of whether epigeic rodents (e.g., mice and rats have a photoreceptor-based magnetic compass similar to that found in amphibians and migratory birds.

  15. Rapid learning of magnetic compass direction by C57BL/6 mice in a 4-armed 'plus' water maze.

    Science.gov (United States)

    Phillips, John B; Youmans, Paul W; Muheim, Rachel; Sloan, Kelly A; Landler, Lukas; Painter, Michael S; Anderson, Christopher R

    2013-01-01

    Magnetoreception has been demonstrated in all five vertebrate classes. In rodents, nest building experiments have shown the use of magnetic cues by two families of molerats, Siberian hamsters and C57BL/6 mice. However, assays widely used to study rodent spatial cognition (e.g. water maze, radial arm maze) have failed to provide evidence for the use of magnetic cues. Here we show that C57BL/6 mice can learn the magnetic direction of a submerged platform in a 4-armed (plus) water maze. Naïve mice were given two brief training trials. In each trial, a mouse was confined to one arm of the maze with the submerged platform at the outer end in a predetermined alignment relative to magnetic north. Between trials, the training arm and magnetic field were rotated by 180(°) so that the mouse had to swim in the same magnetic direction to reach the submerged platform. The directional preference of each mouse was tested once in one of four magnetic field alignments by releasing it at the center of the maze with access to all four arms. Equal numbers of responses were obtained from mice tested in the four symmetrical magnetic field alignments. Findings show that two training trials are sufficient for mice to learn the magnetic direction of the submerged platform in a plus water maze. The success of these experiments may be explained by: (1) absence of alternative directional cues (2), rotation of magnetic field alignment, and (3) electromagnetic shielding to minimize radio frequency interference that has been shown to interfere with magnetic compass orientation of birds. These findings confirm that mice have a well-developed magnetic compass, and give further impetus to the question of whether epigeic rodents (e.g., mice and rats) have a photoreceptor-based magnetic compass similar to that found in amphibians and migratory birds.

  16. Fragmentation of Rapid Eye Movement and Nonrapid Eye Movement Sleep without Total Sleep Loss Impairs Hippocampus-Dependent Fear Memory Consolidation.

    Science.gov (United States)

    Lee, Michael L; Katsuyama, Ângela M; Duge, Leanne S; Sriram, Chaitra; Krushelnytskyy, Mykhaylo; Kim, Jeansok J; de la Iglesia, Horacio O

    2016-11-01

    Sleep is important for consolidation of hippocampus-dependent memories. It is hypothesized that the temporal sequence of nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep is critical for the weakening of nonadaptive memories and the subsequent transfer of memories temporarily stored in the hippocampus to more permanent memories in the neocortex. A great body of evidence supporting this hypothesis relies on behavioral, pharmacological, neural, and/or genetic manipulations that induce sleep deprivation or stage-specific sleep deprivation. We exploit an experimental model of circadian desynchrony in which intact animals are not deprived of any sleep stage but show fragmentation of REM and NREM sleep within nonfragmented sleep bouts. We test the hypothesis that the shortening of NREM and REM sleep durations post-training will impair memory consolidation irrespective of total sleep duration. When circadian-desynchronized animals are trained in a hippocampus-dependent contextual fear-conditioning task they show normal short-term memory but impaired long-term memory consolidation. This impairment in memory consolidation is positively associated with the post-training fragmentation of REM and NREM sleep but is not significantly associated with the fragmentation of total sleep or the total amount of delta activity. We also show that the sleep stage fragmentation resulting from circadian desynchrony has no effect on hippocampus-dependent spatial memory and no effect on hippocampus-independent cued fear-conditioning memory. Our findings in an intact animal model, in which sleep deprivation is not a confounding factor, support the hypothesis that the stereotypic sequence and duration of sleep stages play a specific role in long-term hippocampus-dependent fear memory consolidation. © 2016 Associated Professional Sleep Societies, LLC.

  17. Fight or flight? Dream content during sleepwalking/sleep terrors vs. rapid eye movement sleep behavior disorder.

    Science.gov (United States)

    Uguccioni, Ginevra; Golmard, Jean-Louis; de Fontréaux, Alix Noël; Leu-Semenescu, Smaranda; Brion, Agnès; Arnulf, Isabelle

    2013-05-01

    Dreams enacted during sleepwalking or sleep terrors (SW/ST) may differ from those enacted during rapid eye movement sleep behavior disorder (RBD). Subjects completed aggression, depression, and anxiety questionnaires. The mentations associated with SW/ST and RBD behaviors were collected over their lifetime and on the morning after video polysomnography (PSG). The reports were analyzed for complexity, length, content, setting, bizarreness, and threat. Ninety-one percent of 32 subjects with SW/ST and 87.5% of 24 subjects with RBD remembered an enacted dream (121 dreams in a lifetime and 41 dreams recalled on the morning). These dreams were more complex and less bizarre, with a higher level of aggression in the RBD than in SW/ST subjects. In contrast, we found low aggression, anxiety, and depression scores during the daytime in both groups. As many as 70% of enacted dreams in SW/ST and 60% in RBD involved a threat, but there were more misfortunes and disasters in the SW/ST dreams and more human and animal aggressions in the RBD dreams. The response to these threats differed, as the sleepwalkers mostly fled from a disaster (and 25% fought back when attacked), while 75% of RBD subjects counterattacked when assaulted. The dreams setting included their bedrooms in 42% SW/ST dreams, though this finding was exceptional in the RBD dreams. Different threat simulations and modes of defense seem to play a role during dream-enacted behaviors (e.g., fleeing a disaster during SW/ST, counterattacking a human or animal assault during RBD), paralleling and exacerbating the differences observed between normal dreaming in nonrapid eye movement (NREM) vs rapid eye movement (REM) sleep. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Automation of angular movement of the arm neutron diffractometer; Automatizacion del movimiento angular del brazo del difractometro de neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar H, F.; Herrera A, E.; Quintana C, G. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Torres R, C. E.; Reyes V, M., E-mail: fortunato.aguilar@inin.gob.mx [Instituto Tecnologico de Toluca, Av. Tecnologico s/n, Ex-Rancho La Virgen, Metepec, Estado de Mexico (Mexico)

    2015-09-15

    A technique to determine the crystal structure of some materials is the neutron diffraction. This technique consists on placing the material in question in a monoenergetic neutron beam obtained by neutron diffraction in a monochromator crystal. The neutron energy depends of the diffraction angle. The Instituto Nacional de Investigaciones Nucleares has a neutron diffractometer and monochromator crystals of pyrolytic graphite. This crystal can be selecting the neutron energy depending on the angle of diffraction in the glass. The radiation source for the neutron diffractometer is the TRIGA Mark III reactor of the Nuclear Center Dr. Nabor Carrillo Flores. During their operation are also obtained besides neutrons, β and γ radiation. The interest is to have thermal neutrons, so fast neutrons and γ rays are removed using appropriate shielding. The average neutron fluxes of the radial port RE2 of neutron diffractometer at power 1 MW are: heat flow 2,466 x 10{sup 8} n cm{sup -2} sec{sup -1} and fast flow 1,239 x 10{sup 8} n cm{sup -2} sec{sup -1}. The neutron detector is housed in a shield mounted on a mechanical linkage with which the diffraction angle is selected, and therefore the energy of the neutrons. The movement of this joint was performed by the equipment operator manually, so that accuracy to select the diffraction angle was not good and the process rather slow. Therefore a mechanical system was designed, automated by means of a motor as an actuator, a system of force transmission and an electronic control in order that the operator will schedule the diffraction angles and allow the count in the neutrons detection system in a simple manner. (Author)

  19. Chess players' eye movements reveal rapid recognition of complex visual patterns: Evidence from a chess-related visual search task.

    Science.gov (United States)

    Sheridan, Heather; Reingold, Eyal M

    2017-03-01

    To explore the perceptual component of chess expertise, we monitored the eye movements of expert and novice chess players during a chess-related visual search task that tested anecdotal reports that a key differentiator of chess skill is the ability to visualize the complex moves of the knight piece. Specifically, chess players viewed an array of four minimized chessboards, and they rapidly searched for the target board that allowed a knight piece to reach a target square in three moves. On each trial, there was only one target board (i.e., the "Yes" board), and for the remaining "lure" boards, the knight's path was blocked on either the first move (the "Easy No" board) or the second move (i.e., "the Difficult No" board). As evidence that chess experts can rapidly differentiate complex chess-related visual patterns, the experts (but not the novices) showed longer first-fixation durations on the "Yes" board relative to the "Difficult No" board. Moreover, as hypothesized, the task strongly differentiated chess skill: Reaction times were more than four times faster for the experts relative to novices, and reaction times were correlated with within-group measures of expertise (i.e., official chess ratings, number of hours of practice). These results indicate that a key component of chess expertise is the ability to rapidly recognize complex visual patterns.

  20. Cerebral O2 metabolism and cerebral blood flow in humans during deep and rapid-eye-movement sleep

    DEFF Research Database (Denmark)

    Madsen, P L; Schmidt, J F; Wildschiødtz, Gordon

    1991-01-01

    on examination of this question. We have now measured CBF and CMRO2 in young healthy volunteers using the Kety-Schmidt technique with 133Xe as the inert gas. Measurements were performed during wakefulness, deep sleep (stage 3/4), and rapid-eye-movement (REM) sleep as verified by standard polysomnography...... associated with light anesthesia. During REM sleep (dream sleep) CMRO2 was practically the same as in the awake state. Changes in CBF paralleled changes in CMRO2 during both deep and REM sleep.......It could be expected that the various stages of sleep were reflected in variation of the overall level of cerebral activity and thereby in the magnitude of cerebral metabolic rate of oxygen (CMRO2) and cerebral blood flow (CBF). The elusive nature of sleep imposes major methodological restrictions...

  1. Vasoactive intestinal polypeptide excites medial pontine reticular formation neurons in the brainstem rapid eye movement sleep-induction zone

    DEFF Research Database (Denmark)

    Kohlmeier, Kristi Anne; Reiner, P B

    1999-01-01

    Although it has long been known that microinjection of the cholinergic agonist carbachol into the medial pontine reticular formation (mPRF) induces a state that resembles rapid eye movement (REM) sleep, it is likely that other transmitters contribute to mPRF regulation of behavioral states. A key...... candidate is the peptide vasoactive intestinal polypeptide (VIP), which innervates the mPRF and induces REM sleep when injected into this region of the brainstem. To begin understanding the cellular mechanisms underlying this phenomenon, we examined the effects of VIP on mPRF cells using whole-cell patch...... conclude that VIP excites mPRF neurons by activation of a sodium current. This effect is mediated at least in part by G-protein stimulation of adenylyl cyclase, cAMP, and protein kinase A. These data suggest that VIP may play a physiological role in REM induction by its actions on mPRF neurons....

  2. Automated analysis of connected speech reveals early biomarkers of Parkinson's disease in patients with rapid eye movement sleep behaviour disorder.

    Science.gov (United States)

    Hlavnička, Jan; Čmejla, Roman; Tykalová, Tereza; Šonka, Karel; Růžička, Evžen; Rusz, Jan

    2017-02-02

    For generations, the evaluation of speech abnormalities in neurodegenerative disorders such as Parkinson's disease (PD) has been limited to perceptual tests or user-controlled laboratory analysis based upon rather small samples of human vocalizations. Our study introduces a fully automated method that yields significant features related to respiratory deficits, dysphonia, imprecise articulation and dysrhythmia from acoustic microphone data of natural connected speech for predicting early and distinctive patterns of neurodegeneration. We compared speech recordings of 50 subjects with rapid eye movement sleep behaviour disorder (RBD), 30 newly diagnosed, untreated PD patients and 50 healthy controls, and showed that subliminal parkinsonian speech deficits can be reliably captured even in RBD patients, which are at high risk of developing PD or other synucleinopathies. Thus, automated vocal analysis should soon be able to contribute to screening and diagnostic procedures for prodromal parkinsonian neurodegeneration in natural environments.

  3. Dopamine agonist suppression of rapid-eye-movement sleep is secondary to sleep suppression mediated via limbic structures

    Energy Technology Data Exchange (ETDEWEB)

    Miletich, R.S.

    1985-01-01

    The effects of pergolide, a direct dopamine receptor agonist, on sleep and wakefulness, motor behavior and /sup 3/H-spiperone specific binding in limbic structures and striatum in rats was studied. The results show that pergolide induced a biphasic dose effect, with high doses increasing wakefulness and suppressing sleep while low dose decreased wakefulness, but increased sleep. It was shown that pergolide-induced sleep suppression was blocked by ..cap alpha..-glupenthixol and pimozide, two dopamine receptor antagonists. It was further shown that pergolide merely delayed the rebound resulting from rapid-eye-movement (REM) sleep deprivation, that dopamine receptors stimulation had no direct effect on the period, phase or amplitude of the circadian rhythm of REM sleep propensity and that there was no alteration in the coupling of REM sleep episodes with S/sub 2/ episodes. Rapid-eye-movement sleep deprivation resulted in increased sensitivity to the pergolide-induced wakefulness stimulation and sleep suppression and pergolide-induced motor behaviors of locomotion and head bobbing. /sup 3/H-spiperone specific binding to dopamine receptors was shown to be altered by REM sleep deprivation in the subcortical limbic structures. It is concluded that the REM sleep suppressing action of dopamine receptor stimulation is secondary to sleep suppression per se and not secondary to a unique effect on the REM sleep. Further, it is suggested that the wakefulness stimulating action of dopamine receptor agonists is mediated by activation of the dopamine receptors in the terminal areas of the mesolimbocortical dopamine projection system.

  4. Rapid movement of wastewater from on-site disposal systems into surface waters in the lower Florida Keys

    Science.gov (United States)

    Paul, John H.; McLaughlin, Molly R.; Griffin, Dale W.; Lipp, Erin K.; Stokes, Rodger; Rose, Joan B.

    2000-01-01

    Viral tracer studies have been used previously to study the potential for wastewater contamination of surface marine waters in the Upper and Middle Florida Keys. Two bacteriophages, the marine bacteriophage φHSIC and the Salmonella phage PRD1, were used as tracers in injection well and septic tank studies in Saddlebunch Keys of the Lower Florida Keys and in septic tank studies in Boot Key Harbor, Marathon, of the Middle Keys. In Boot Key Harbor, both phages were detected in a canal adjacent to the seeded septic tank within 3 h 15 min of the end of the seed period. The tracer was then detected at all sampling sites in Boot Key Harbor, including one on the opposite side of U. S. Highway 1 in Florida Bay, and at an Atlantic Ocean beach outside Boot Key Harbor. Rates of migration based on first appearance of the phage ranged from 1.7 to 57.5 m h-1. In Saddlebunch Keys, φHSIC and PRD1 were used to seed a residential septic tank and a commercial injection well. The septic tank tracer was not found in any surface water samples. The injection well tracer was first detected at a site most distant from the seed site, a channel that connected Sugarloaf Sound with the Atlantic Ocean. The rate of tracer migration from the injection well to this channel ranged from 66.8 to 141 m h-1. Both tracer studies showed a rapid movement of wastewater from on-site sewage treatment and disposal systems in a southeasterly direction toward the reef tract and Atlantic Ocean, with preferential movement through tidal channels. These studies indicate that wastewater disposal systems currently in widespread use in the Florida Keys can rapidly contaminate the marine environment.

  5. Fluorescence-tracking of activation gating in human ERG channels reveals rapid S4 movement and slow pore opening.

    Directory of Open Access Journals (Sweden)

    Zeineb Es-Salah-Lamoureux

    2010-05-01

    Full Text Available hERG channels are physiologically important ion channels which mediate cardiac repolarization as a result of their unusual gating properties. These are very slow activation compared with other mammalian voltage-gated potassium channels, and extremely rapid inactivation. The mechanism of slow activation is not well understood and is investigated here using fluorescence as a direct measure of S4 movement and pore opening.Tetramethylrhodamine-5-maleimide (TMRM fluorescence at E519 has been used to track S4 voltage sensor movement, and channel opening and closing in hERG channels. Endogenous cysteines (C445 and C449 in the S1-S2 linker bound TMRM, which caused a 10 mV hyperpolarization of the V((1/2 of activation to -27.5+/-2.0 mV, and showed voltage-dependent fluorescence signals. Substitution of S1-S2 linker cysteines with valines allowed unobstructed recording of S3-S4 linker E519C and L520C emission signals. Depolarization of E519C channels caused rapid initial fluorescence quenching, fit with a double Boltzmann relationship, F-V(ON, with V((1/2 (,1 = -37.8+/-1.7 mV, and V((1/2 (,2 = 43.5+/-7.9 mV. The first phase, V((1/2 (,1, was approximately 20 mV negative to the conductance-voltage relationship measured from ionic tail currents (G-V((1/2 = -18.3+/-1.2 mV, and relatively unchanged in a non-inactivating E519C:S620T mutant (V((1/2 = -34.4+/-1.5 mV, suggesting the fast initial fluorescence quenching tracked S4 voltage sensor movement. The second phase of rapid quenching was absent in the S620T mutant. The E519C fluorescence upon repolarization (V((1/2 = -20.6+/-1.2, k = 11.4 mV and L520C quenching during depolarization (V((1/2 = -26.8+/-1.0, k = 13.3 mV matched the respective voltage dependencies of hERG ionic tails, and deactivation time constants from -40 to -110 mV, suggesting they detected pore-S4 rearrangements related to ionic current flow during pore opening and closing.THE DATA INDICATE: 1 that rapid environmental changes occur at the

  6. Comparison of three-dimensional, assist-as-needed robotic arm/hand movement training provided with Pneu-WREX to conventional tabletop therapy after chronic stroke.

    Science.gov (United States)

    Reinkensmeyer, David J; Wolbrecht, Eric T; Chan, Vicky; Chou, Cathy; Cramer, Steven C; Bobrow, James E

    2012-11-01

    Robot-assisted movement training can help individuals with stroke reduce arm and hand impairment, but robot therapy is typically only about as effective as conventional therapy. Refining the way that robots assist during training may make them more effective than conventional therapy. Here, the authors measured the therapeutic effect of a robot that required individuals with a stroke to achieve virtual tasks in three dimensions against gravity. The robot continuously estimated how much assistance patients needed to perform the tasks and provided slightly less assistance than needed to reduce patient slacking. Individuals with a chronic stroke (n = 26; baseline upper limb Fugl-Meyer score, 23 ± 8) were randomized into two groups and underwent 24 one-hour training sessions over 2 mos. One group received the assist-as-needed robot training and the other received conventional tabletop therapy with the supervision of a physical therapist. Training helped both groups significantly reduce their motor impairment, as measured by the primary outcome measure, the Fugl-Meyer score, but the improvement was small (3.0 ± 4.9 points for robot therapy vs. 0.9 ± 1.7 for conventional therapy). There was a trend for greater reduction for the robot-trained group (P = 0.07). The robot group largely sustained this gain at the 3-mo follow-up. The robot-trained group also experienced significant improvements in Box and Blocks score and hand grip strength, whereas the control group did not, but these improvements were not sustained at follow-up. In addition, the robot-trained group showed a trend toward greater improvement in sensory function, as measured by the Nottingham Sensory Test (P = 0.06). These results suggest that in patients with chronic stroke and moderate-severe deficits, assisting in three-dimensional virtual tasks with an assist-as-needed controller may make robotic training more effective than conventional tabletop training.

  7. Early detection of Parkinson’s diseases by using the relation between time response and movement characteristics of human’s arms

    Directory of Open Access Journals (Sweden)

    Prasert Namwet

    2016-08-01

    Full Text Available Parkinson’s and stroke diseases are closely linked to the brain of the elderly. This study was to investigate the early detecting method of Parkinson’s disease by using the relation between the brain time response and the arm movement characteristics. 120 Healthy people were examined and classified into 4 groups of ages (60 years old.The relationship between the two parameters were conducted by using the self-made electronics set which had an accelerometer attached on the hammer; and pattern generator using star-pattern with 9-position lighted keypad. Several simple and complex light patterns were designed to test the brain function of the elderly. The experimental treatments were subjected to 4×2 Factorial Experiment in Completely Randomized Design (CRD. The results showed that the time response of the group of+60’s years old was the longest compared with other group with P<0.01. Based on the experiments on pattern-position approach, those selected samples with 4 groups of age completed the experiment with a sample pattern faster than the complex pattern in all 4 groups of age with P<0.01. The acceleration signal’s patterns in 20-40 years old and +60 years old were found polynomial and linear signal patterns, respectively. The relationship between the time response and acceleration signal were found negative monotonic correlated ( = 0.835, P < 0.01. Therefore, this finding could identify the healthy people without Parkinson’s disease with accuracy of 99.58 %. The results could be concluded that relationship between the time response and the acceleration signal could predict Parkinson’s disease and related diseases in the future.

  8. How do octopuses use their arms?

    Science.gov (United States)

    Mather, J A

    1998-09-01

    A taxonomy of the movement patterns of the 8 flexible arms of octopuses is constructed. Components consist of movements of the arm itself, the ventral suckers and their stalks, as well as the relative position of arms and the skin web between them. Within 1 arm, combinations of components result in a variety of behaviors. At the level of all arms, 1 group of behaviors is described as postures, on the basis of the spread of all arms and the web to make a 2-dimensional surface whose position differs in the 3rd dimension. Another group of arm behaviors is actions, more or less coordinated and involving several to all arms. Arm control appears to be based on radial symmetry, relative equipotentiality of all arms, relative independence of each arm, and separability of components within the arm. The types and coordination of arm behaviors are discussed with relationship to biomechanical limits, muscle structures, and neuronal programming.

  9. A novel non-rapid-eye movement and rapid-eye-movement parasomnia with sleep breathing disorder associated with antibodies to IgLON5: a case series, characterisation of the antigen, and post-mortem study.

    Science.gov (United States)

    Sabater, Lidia; Gaig, Carles; Gelpi, Ellen; Bataller, Luis; Lewerenz, Jan; Torres-Vega, Estefanía; Contreras, Angeles; Giometto, Bruno; Compta, Yaroslau; Embid, Cristina; Vilaseca, Isabel; Iranzo, Alex; Santamaría, Joan; Dalmau, Josep; Graus, Francesc

    2014-06-01

    Autoimmunity might be associated with or implicated in sleep and neurodegenerative disorders. We aimed to describe the features of a novel neurological syndrome associated with prominent sleep dysfunction and antibodies to a neuronal antigen. In this observational study, we used clinical and video polysomnography to identify a novel sleep disorder in three patients referred to the Sleep Unit of Hospital Clinic, University of Barcelona, Spain, for abnormal sleep behaviours and obstructive sleep apnoea. These patients had antibodies against a neuronal surface antigen, which were also present in five additional patients referred to our laboratory for antibody studies. These five patients had been assessed with polysomnography, which was done in our sleep unit in one patient and the recording reviewed in a second patient. Two patients underwent post-mortem brain examination. Immunoprecipitation and mass spectrometry were used to characterise the antigen and develop an assay for antibody testing. Serum or CSF from 298 patients with neurodegenerative, sleep, or autoimmune disorders served as control samples. All eight patients (five women; median age at disease onset 59 years [range 52-76]) had abnormal sleep movements and behaviours and obstructive sleep apnoea, as confirmed by polysomnography. Six patients had chronic progression with a median duration from symptom onset to death or last visit of 5 years (range 2-12); in four the sleep disorder was the initial and most prominent feature, and in two it was preceded by gait instability followed by dysarthria, dysphagia, ataxia, or chorea. Two patients had a rapid progression with disequilibrium, dysarthria, dysphagia, and central hypoventilation, and died 2 months and 6 months, respectively, after symptom onset. In five of five patients, video polysomnography showed features of obstructive sleep apnoea, stridor, and abnormal sleep architecture (undifferentiated non-rapid-eye-movement [non-REM] sleep or poorly structured

  10. Baseline Levels of Rapid Eye Movement Sleep May Protect Against Excessive Activity in Fear-Related Neural Circuitry.

    Science.gov (United States)

    Lerner, Itamar; Lupkin, Shira M; Sinha, Neha; Tsai, Alan; Gluck, Mark A

    2017-11-15

    Sleep, and particularly rapid eye movement sleep (REM), has been implicated in the modulation of neural activity following fear conditioning and extinction in both human and animal studies. It has long been presumed that such effects play a role in the formation and persistence of posttraumatic stress disorder, of which sleep impairments are a core feature. However, to date, few studies have thoroughly examined the potential effects of sleep prior to conditioning on subsequent acquisition of fear learning in humans. Furthermore, these studies have been restricted to analyzing the effects of a single night of sleep-thus assuming a state-like relationship between the two. In the current study, we used long-term mobile sleep monitoring and functional neuroimaging (fMRI) to explore whether trait-like variations in sleep patterns, measured in advance in both male and female participants, predict subsequent patterns of neural activity during fear learning. Our results indicate that higher baseline levels of REM sleep predict reduced fear-related activity in, and connectivity between, the hippocampus, amygdala and ventromedial PFC during conditioning. Additionally, skin conductance responses (SCRs) were weakly correlated to the activity in the amygdala. Conversely, there was no direct correlation between REM sleep and SCRs, indicating that REM may only modulate fear acquisition indirectly. In a follow-up experiment, we show that these results are replicable, though to a lesser extent, when measuring sleep over a single night just before conditioning. As such, baseline sleep parameters may be able to serve as biomarkers for resilience, or lack thereof, to trauma. SIGNIFICANCE STATEMENT Numerous studies over the past two decades have established a clear role of sleep in fear-learning processes. However, previous work has focused on the effects of sleep following fear acquisition, thus neglecting the potential effects of baseline sleep levels on the acquisition itself. The

  11. Acute administration of fluoxetine normalizes rapid eye movement sleep abnormality, but not depressive behaviors in olfactory bulbectomized rats.

    Science.gov (United States)

    Wang, Yi-Qun; Tu, Zhi-Cai; Xu, Xing-Yuan; Li, Rui; Qu, Wei-Min; Urade, Yoshihiro; Huang, Zhi-Li

    2012-01-01

    In humans, depression is associated with altered rapid eye movement (REM) sleep. However, the exact nature of the relationship between depressive behaviors and sleep abnormalities is debated. In this study, bilateral olfactory bulbectomy (OBX) was carried out to create a model of depression in rats. The sleep-wake profiles were assayed using a cutting-edge sleep bioassay system, and depressive behaviors were evaluated by open field and forced swimming tests. The monoamine content and monoamine metabolite levels in the brain were determined by a HPLC-electrochemical detection system. OBX rats exhibited a significant increase in REM sleep, especially between 15:00 and 18:00 hours during the light period. Acute treatment with fluoxetine (10 mg/kg, i.p.) immediately abolished the OBX-induced increase in REM sleep, but hyperactivity in the open field test and the time spent immobile in the forced swimming test remained unchanged. Neurochemistry studies revealed that acute administration of fluoxetine increased serotonin (5-HT) levels in the hippocampus, thalamus, and midbrain and decreased levels of the 5-HT metabolite 5-hydroxyindoleacetic acid (5-HIAA). The ratio of 5-HIAA to 5-HT decreased in almost all regions of the brain. These results indicate that acute administration of fluoxetine can reduce the increase in REM sleep but does not change the depressive behaviors in OBX rats, suggesting that there was no causality between REM sleep abnormalities and depressive behaviors in OBX rats. © 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry.

  12. Comparison of rhythmic masticatory muscle activity during non-rapid eye movement sleep in guinea pigs and humans.

    Science.gov (United States)

    Kato, Takafumi; Toyota, Risa; Haraki, Shingo; Yano, Hiroyuki; Higashiyama, Makoto; Ueno, Yoshio; Yano, Hiroshi; Sato, Fumihiko; Yatani, Hirofumi; Yoshida, Atsushi

    2017-09-27

    Rhythmic masticatory muscle activity can be a normal variant of oromotor activity, which can be exaggerated in patients with sleep bruxism. However, few studies have tested the possibility in naturally sleeping animals to study the neurophysiological mechanisms of rhythmic masticatory muscle activity. This study aimed to investigate the similarity of cortical, cardiac and electromyographic manifestations of rhythmic masticatory muscle activity occurring during non-rapid eye movement sleep between guinea pigs and human subjects. Polysomnographic recordings were made in 30 freely moving guinea pigs and in eight healthy human subjects. Burst cycle length, duration and activity of rhythmic masticatory muscle activity were compared with those for chewing. The time between R-waves in the electrocardiogram (RR interval) and electroencephalogram power spectrum were calculated to assess time-course changes in cardiac and cortical activities in relation to rhythmic masticatory muscle activity. In animals, in comparison with chewing, rhythmic masticatory muscle activity had a lower burst activity, longer burst duration and longer cycle length (P motor activation in comparison to human subjects. © 2017 European Sleep Research Society.

  13. Rapid eye movement sleep deprivation disrupts consolidation but not reconsolidation of novel object recognition memory in rats.

    Science.gov (United States)

    Chen, Lin; Tian, Shaowen; Ke, Jie

    2014-03-20

    There is increasing evidence that sleep plays a critical role in memory consolidation. However, there are comparatively few studies that have assessed the relationship between sleep and memory reconsolidation. In the present study, we explored the effects of rapid eye movement sleep deprivation (RSD) on the consolidation (experiment 1) and reconsolidation (experiment 2) of novel object recognition memory in rats. In experiment 1 behavioral procedure involved two training phases: sample and test. Rats were subjected to 6h RSD starting either immediately after sample (exposed to 2 objects) or 6h later. In experiment 2 behavioral procedure involved three training phases: sample, reactivation and test. Rats were subjected to 6h RSD starting either immediately after reactivation (exposed to the same 2 sample objects to reactivate the memory trace) or 6h later. Results from experiment 1 showed that post-sample RSD from 0 to 6h but not 6 to 12h disrupted novel object recognition memory consolidation. However, we found that post-reactivation RSD whether from 0 to 6h or 6 to 12h had no effect on novel object recognition memory reconsolidation in experiment 2. The results indicated that RSD selectively disrupted consolidation of novel object recognition memory, suggesting a dissociation effect of RSD on consolidation and reconsolidation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  14. Why are seizures rare in rapid eye movement sleep? Review of the frequency of seizures in different sleep stages.

    Science.gov (United States)

    Ng, Marcus; Pavlova, Milena

    2013-01-01

    Since the formal characterization of sleep stages, there have been reports that seizures may preferentially occur in certain phases of sleep. Through ascending cholinergic connections from the brainstem, rapid eye movement (REM) sleep is physiologically characterized by low voltage fast activity on the electroencephalogram, REMs, and muscle atonia. Multiple independent studies confirm that, in REM sleep, there is a strikingly low proportion of seizures (~1% or less). We review a total of 42 distinct conventional and intracranial studies in the literature which comprised a net of 1458 patients. Indexed to duration, we found that REM sleep was the most protective stage of sleep against focal seizures, generalized seizures, focal interictal discharges, and two particular epilepsy syndromes. REM sleep had an additional protective effect compared to wakefulness with an average 7.83 times fewer focal seizures, 3.25 times fewer generalized seizures, and 1.11 times fewer focal interictal discharges. In further studies REM sleep has also demonstrated utility in localizing epileptogenic foci with potential translation into postsurgical seizure freedom. Based on emerging connectivity data in sleep, we hypothesize that the influence of REM sleep on seizures is due to a desynchronized EEG pattern which reflects important connectivity differences unique to this sleep stage.

  15. Effects of partial sleep deprivation on slow waves during non-rapid eye movement sleep: A high density EEG investigation.

    Science.gov (United States)

    Plante, David T; Goldstein, Michael R; Cook, Jesse D; Smith, Richard; Riedner, Brady A; Rumble, Meredith E; Jelenchick, Lauren; Roth, Andrea; Tononi, Giulio; Benca, Ruth M; Peterson, Michael J

    2016-02-01

    Changes in slow waves during non-rapid eye movement (NREM) sleep in response to acute total sleep deprivation are well-established measures of sleep homeostasis. This investigation utilized high-density electroencephalography (hdEEG) to examine topographic changes in slow waves during repeated partial sleep deprivation. Twenty-four participants underwent a 6-day sleep restriction protocol. Spectral and period-amplitude analyses of sleep hdEEG data were used to examine changes in slow wave energy, count, amplitude, and slope relative to baseline. Changes in slow wave energy were dependent on the quantity of NREM sleep utilized for analysis, with widespread increases during sleep restriction and recovery when comparing data from the first portion of the sleep period, but restricted to recovery sleep if the entire sleep episode was considered. Period-amplitude analysis was less dependent on the quantity of NREM sleep utilized, and demonstrated topographic changes in the count, amplitude, and distribution of slow waves, with frontal increases in slow wave amplitude, numbers of high-amplitude waves, and amplitude/slopes of low amplitude waves resulting from partial sleep deprivation. Topographic changes in slow waves occur across the course of partial sleep restriction and recovery. These results demonstrate a homeostatic response to partial sleep loss in humans. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  16. Nocturnal agitation in Huntington disease is caused by arousal-related abnormal movements rather than by rapid eye movement sleep behavior disorder.

    Science.gov (United States)

    Neutel, Dulce; Tchikviladzé, Maya; Charles, Perrine; Leu-Semenescu, Smaranda; Roze, Emmanuel; Durr, Alexandra; Arnulf, Isabelle

    2015-06-01

    Patients with Huntington disease (HD) and their spouses often complain of agitation during sleep, but the causes are mostly unknown. To evaluate sleep and nocturnal movements in patients with various HD stages and CAG repeats length. The clinical features and sleep studies of 29 patients with HD were retrospectively collected (11 referred for genotype-phenotype correlations and 18 for agitation during sleep) and compared with those of 29 age- and sex-matched healthy controls. All patients had videopolysomnography, but the movements during arousals were re-analyzed in six patients with HD with stored video. The patients had a longer total sleep period and REM sleep onset latency, but no other differences in sleep than controls. There was no correlation between CAG repeat length and sleep measures, but total sleep time and sleep efficiency were lower in the subgroup with moderate than milder form of HD. Periodic limb movements and REM sleep behavior disorders were excluded, although 2/29 patients had abnormal REM sleep without atonia. In contrast, they had clumsy and opisthotonos-like movements during arousals from non-REM or REM sleep. Some movements were violent and harmful. They might consist of voluntary movements inappropriately involving the proximal part of the limbs on a background of exaggerated hypotonia. Giant (>65 mcV) sleep spindles were observed in seven (24%) patients with HD and one control. The nocturnal agitation in patients with HD seems related to anosognostic voluntary movements on arousals, rather than to REM sleep behavior disorder and other sleep problems. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Rapid eye movement sleep behavior disorder: devising controlled active treatment studies for symptomatic and neuroprotective therapy--a consensus statement from the International Rapid Eye Movement Sleep Behavior Disorder Study Group.

    Science.gov (United States)

    Schenck, C H; Montplaisir, J Y; Frauscher, B; Hogl, B; Gagnon, J-F; Postuma, R; Sonka, K; Jennum, P; Partinen, M; Arnulf, I; Cochen de Cock, V; Dauvilliers, Y; Luppi, P-H; Heidbreder, A; Mayer, G; Sixel-Döring, F; Trenkwalder, C; Unger, M; Young, P; Wing, Y K; Ferini-Strambi, L; Ferri, R; Plazzi, G; Zucconi, M; Inoue, Y; Iranzo, A; Santamaria, J; Bassetti, C; Möller, J C; Boeve, B F; Lai, Y Y; Pavlova, M; Saper, C; Schmidt, P; Siegel, J M; Singer, C; St Louis, E; Videnovic, A; Oertel, W

    2013-08-01

    We aimed to provide a consensus statement by the International Rapid Eye Movement Sleep Behavior Disorder Study Group (IRBD-SG) on devising controlled active treatment studies in rapid eye movement sleep behavior disorder (RBD) and devising studies of neuroprotection against Parkinson disease (PD) and related neurodegeneration in RBD. The consensus statement was generated during the fourth IRBD-SG symposium in Marburg, Germany in 2011. The IRBD-SG identified essential methodologic components for a randomized trial in RBD, including potential screening and diagnostic criteria, inclusion and exclusion criteria, primary and secondary outcomes for symptomatic therapy trials (particularly for melatonin and clonazepam), and potential primary and secondary outcomes for eventual trials with disease-modifying and neuroprotective agents. The latter trials are considered urgent, given the high conversion rate from idiopathic RBD (iRBD) to Parkinsonian disorders (i.e., PD, dementia with Lewy bodies [DLB], multiple system atrophy [MSA]). Six inclusion criteria were identified for symptomatic therapy and neuroprotective trials: (1) diagnosis of RBD needs to satisfy the International Classification of Sleep Disorders, second edition, (ICSD-2) criteria; (2) minimum frequency of RBD episodes should preferably be ⩾2 times weekly to allow for assessment of change; (3) if the PD-RBD target population is included, it should be in the early stages of PD defined as Hoehn and Yahr stages 1-3 in Off (untreated); (4) iRBD patients with soft neurologic dysfunction and with operational criteria established by the consensus of study investigators; (5) patients with mild cognitive impairment (MCI); and (6) optimally treated comorbid OSA. Twenty-four exclusion criteria were identified. The primary outcome measure for RBD treatment trials was determined to be the Clinical Global Impression (CGI) efficacy index, consisting of a four-point scale with a four-point side-effect scale. Assessment of

  18. Magnetic Resonance Imaging Biomarkers to Assess Substantia Nigra Damage in Idiopathic Rapid Eye Movement Sleep Behavior Disorder.

    Science.gov (United States)

    Pyatigorskaya, Nadya; Gaurav, Rahul; Arnaldi, Dario; Leu-Semenescu, Smaranda; Yahia-Cherif, Lydia; Valabregue, Romain; Vidailhet, Marie; Arnulf, Isabelle; Lehéricy, Stephane

    2017-11-01

    Idiopathic rapid eye movement sleep behavior disorder (iRBD) is considered to be a prodromal stage of Parkinson's disease (PD). At PD onset, 40 to 70% of the dopaminergic neurons in the substantia nigra (SN) are already lost. Thus, milder SN damage is expected in participants with iRBD. We aimed to quantify SN damage in participants with iRBD using multimodal magnetic resonance imaging (MRI) and to determine biomarker efficacy in preclinical Parkinsonism. Nineteen participants with iRBD and 18 controls underwent 3-Tesla MRI, including diffusion tensor imaging, neuromelanin (NM)-sensitive imaging, and T2* mapping. Regions of interest in the SN area were drawn in NM-sensitive and T2-weighted images. The volume and normalized signal intensity in NM-sensitive images, R2*, and diffusion tensor measures were quantified in the SN. Additionally, two raters performed visual analysis of the SN using the NM-sensitive images. Participants with iRBD showed a reduction in the NM-sensitive volume and signal intensity and a decrease in fractional anisotropy (FA) versus controls, but showed no differences in axial, radial, or mean diffusivity or in R2*. For NM-sensitive volume and signal intensity, the receiver operating characteristic analysis discriminated between participants with iRBD and controls with a diagnostic accuracy of 0.86 and 0.79, respectively, whereas the accuracy was 0.77 for FA. The three biomarkers had a combined accuracy of 0.92. The fraction of participants correctly characterized by visual assessment was 0.81. NM-sensitive imaging and FA allowed for the detection of SN damage in participants with iRBD with good diagnostic accuracy. These measures may represent valuable biomarkers for prodromal Parkinsonism. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  19. Time-of-night variations in the story-like organization of dream experience developed during rapid eye movement sleep.

    Science.gov (United States)

    Cipolli, Carlo; Guazzelli, Mario; Bellucci, Claudia; Mazzetti, Michela; Palagini, Laura; Rosenlicht, Nicholas; Feinberg, Irwin

    2015-04-01

    This study aimed to investigate the cycles (2nd/4th) and duration-related (5/10 min) variations in the story-like organization of dream experience elaborated during rapid eye movement (REM) sleep. Dream reports were analysed using story grammar rules. Reports were provided by those subjects (14 of 22) capable of reporting a dream after each of the four awakenings provoked in 2 consecutive nights during REM sleep of the 2nd and 4th cycles, after periods of either 5 or 10 min, counterbalanced across the nights. Two researchers who were blind as to the sleep condition scored the dream reports independently. The values of the indicators of report length (measured as value of total word count) and of story-like organization of dream reports were matched taking time-of-night (2nd and 4th cycles) and REM duration (5 versus 10 min) as factors. Two-way analyses of variance showed that report length increased significantly in 4th-cycle REM sleep and nearly significantly for longer REM duration, whereas the number of dream-stories per report did not vary. The indices of sequential (number of statements describing the event structure developed in the story) and hierarchical (number of episodes per story) organization increased significantly only in dream-stories reported after 10 min of 4th-cycle REM sleep. These findings indicate that the characteristics of structural organization of dream-stories vary along with time of night, and suggest that the elaboration of a long and complex dream-story requires a fairly long time and the availability of a great amount of cognitive resources to maintain its continuity and coherence. © 2014 European Sleep Research Society.

  20. Study on microstructure of corpus striatum in patients with idiopathic rapid eye movement sleep behavior disorder using magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Ya-meng ZHANG

    2017-07-01

    Full Text Available Objective To investigate the structure of corpus striatum and the integrity of white matter fiber in patients with Parkinson's disease (PD and idiopathic rapid eye movement sleep behavior disorder (iRBD.  Methods Twelve patients with iRBD, 12 patients with PD and 10 healthy subjects that were well matched in gender, age and education were enrolled in this study. Head MRI examination was performed to all subjects to observe the changes of corpus striatum structure (the gray matter volume and the integrity of white matter fiber [fractional anisotropy (FA] by combining voxel?based morphometry (VBM and diffusion tensor imaging (DTI.  Results Compared with healthy subjects, the gray matter volume of left caudate nucleus was significantly decreased (P < 0.005, and FA values of left caudate nucleus (P < 0.005, right caudate nucleus (P < 0.001 and right putamen (P < 0.05 were all significantly reduced in iRBD patients; FA value of right putamen was significantly decreased in PD patients (P < 0.05. Compared with PD patients, the gray matter volume of left caudate nucleus of iRBD patients was significantly reduced (P < 0.001, FA values of left caudate nucleus (P < 0.01 and right caudate nucleus (P < 0.005 of iRBD patients were significantly reduced.  Conclusions There is atrophy of gray matter volume and extensive white matter fiber impairment in corpus striatum of patients with iRBD, and the white matter fiber impairment was similar to PD, which provides an anatomical evidence for iRBD being presymptom of PD. DOI: 10.3969/j.issn.1672-6731.2017.05.008

  1. Prevalence of rapid eye movement sleep behavior disorder (RBD) in Parkinson's disease: a meta and meta-regression analysis.

    Science.gov (United States)

    Zhang, Xiaona; Sun, Xiaoxuan; Wang, Junhong; Tang, Liou; Xie, Anmu

    2017-01-01

    Rapid eye movement sleep behavior disorder (RBD) is thought to be one of the most frequent preceding symptoms of Parkinson's disease (PD). However, the prevalence of RBD in PD stated in the published studies is still inconsistent. We conducted a meta and meta-regression analysis in this paper to estimate the pooled prevalence. We searched the electronic databases of PubMed, ScienceDirect, EMBASE and EBSCO up to June 2016 for related articles. STATA 12.0 statistics software was used to calculate the available data from each research. The prevalence of RBD in PD patients in each study was combined to a pooled prevalence with a 95 % confidence interval (CI). Subgroup analysis and meta-regression analysis were performed to search for the causes of the heterogeneity. A total of 28 studies with 6869 PD cases were deemed eligible and included in our meta-analysis based on the inclusion and exclusion criteria. The pooled prevalence of RBD in PD was 42.3 % (95 % CI 37.4-47.1 %). In subgroup analysis and meta-regression analysis, we found that the important causes of heterogeneity were the diagnosis criteria of RBD and age of PD patients (P = 0.016, P = 0.019, respectively). The results indicate that nearly half of the PD patients are suffering from RBD. Older age and longer duration are risk factors for RBD in PD. We can use the minimal diagnosis criteria for RBD according to the International Classification of Sleep Disorders to diagnose RBD patients in our daily work if polysomnography is not necessary.

  2. Honokiol promotes non-rapid eye movement sleep via the benzodiazepine site of the GABA(A) receptor in mice.

    Science.gov (United States)

    Qu, Wei-Min; Yue, Xiao-Fang; Sun, Yu; Fan, Kun; Chen, Chang-Rui; Hou, Yi-Ping; Urade, Yoshihiro; Huang, Zhi-Li

    2012-10-01

    Decoctions of the Chinese herb houpu contain honokiol and are used to treat a variety of mental disorders, including depression. Depression commonly presents alongside sleep disorders and sleep disturbances, which appear to be a major risk factor for depression. Here, we have evaluated the somnogenic effect of honokiol and the mechanisms involved. Honokiol was administered i.p. at 20:00 h in mice. Flumazenil, an antagonist at the benzodiazepine site of the GABA(A) receptor, was administered i.p. 15 min before honokiol. The effects of honokiol were measured by EEG and electromyogram (EMG), c-Fos expression and in vitro electrophysiology. Honokiol (10 and 20 mg·kg⁻¹) significantly shortened the sleep latency to non-rapid eye movement (non-REM, NREM) sleep and increased the amount of NREM sleep. Honokiol increased the number of state transitions from wakefulness to NREM sleep and, subsequently, from NREM sleep to wakefulness. However, honokiol had no effect on either the amount of REM sleep or EEG power density of both NREM and REM sleep. Honokiol increased c-Fos expression in ventrolateral preoptic area (VLPO) neurons, as examined by immunostaining, and excited sleep-promoting neurons in the VLPO by whole-cell patch clamping in the brain slice. Pretreatment with flumazenil abolished the somnogenic effects and activation of the VLPO neurons by honokiol. Honokiol promoted NREM sleep by modulating the benzodiazepine site of the GABA(A) receptor, suggesting potential applications in the treatment of insomnia, especially for patients who experience difficulty in falling and staying asleep. © 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.

  3. Probable rapid eye movement sleep behavior disorder, nocturnal disturbances and quality of life in patients with Parkinson’s disease: a case-controlled study using the rapid eye movement sleep behavior disorder screening questionnaire

    Directory of Open Access Journals (Sweden)

    Suzuki Keisuke

    2013-02-01

    Full Text Available Abstract Background Increasing evidence provides a clear association between rapid eye movement sleep behavior disorders (RBD and Parkinson’s disease (PD, but the clinical features that determine the co-morbidity of RBD and PD are not yet fully understood. Methods We evaluated the characteristics of nocturnal disturbances and other motor and non-motor features related to RBD in patients with PD and the impact of RBD on their quality of life. Probable RBD (pRBD was evaluated using the Japanese version of the RBD screening questionnaire (RBDSQ-J. Results A significantly higher frequency of pRBD was observed in PD patients than in the controls (RBDSQ-J ≥ 5 or ≥ 6: 29.0% vs. 8.6%; 17.2% vs. 2.2%, respectively. After excluding restless legs syndrome and snorers in the PD patients, the pRBD group (RBDSQ-J≥5 showed higher scores compared with the non-pRBD group on the Parkinson’s disease sleep scale-2 (PDSS-2 total and three-domain scores. Early morning dystonia was more frequent in the pRBD group. The Parkinson’s Disease Questionnaire (PDQ-39 domain scores for cognition and emotional well-being were higher in the patients with pRBD than in the patients without pRBD. There were no differences between these two groups with respect to the clinical subtype, disease severity or motor function. When using a cut-off of RBDSQ-J = 6, a similar trend was observed for the PDSS-2 and PDQ-39 scores. Patients with PD and pRBD had frequent sleep onset insomnia, distressing dreams and hallucinations. The stepwise linear regression analysis showed that the PDSS-2 domain “motor symptoms at night”, particularly the PDSS sub-item 6 “distressing dreams”, was the only predictor of RBDSQ-J in PD. Conclusion Our results indicate a significant impact of RBD co-morbidity on night-time disturbances and quality of life in PD, particularly on cognition and emotional well-being. RBDSQ may be a useful tool for not only screening RBD in PD patients

  4. The Clinical Phenotype of Idiopathic Rapid Eye Movement Sleep Behavior Disorder at Presentation: A Study in 203 Consecutive Patients.

    Science.gov (United States)

    Fernández-Arcos, Ana; Iranzo, Alex; Serradell, Mónica; Gaig, Carles; Santamaria, Joan

    2016-01-01

    To describe the clinical phenotype of idiopathic rapid eye movement (REM) sleep behavior disorder (IRBD) at presentation in a sleep center. Clinical history review of 203 consecutive patients with IRBD identified between 1990 and 2014. IRBD was diagnosed by clinical history plus video-polysomnographic demonstration of REM sleep with increased electromyographic activity linked to abnormal behaviors. Patients were 80% men with median age at IRBD diagnosis of 68 y (range, 50-85 y). In addition to the already known clinical picture of IRBD, other important features were apparent: 44% of the patients were not aware of their dream-enactment behaviors and 70% reported good sleep quality. In most of these cases bed partners were essential to convince patients to seek medical help. In 11% IRBD was elicited only after specific questioning when patients consulted for other reasons. Seven percent did not recall unpleasant dreams. Leaving the bed occurred occasionally in 24% of subjects in whom dementia with Lewy bodies often developed eventually. For the correct diagnosis of IRBD, video-polysomnography had to be repeated in 16% because of insufficient REM sleep or electromyographic artifacts from coexistent apneas. Some subjects with comorbid obstructive sleep apnea reported partial improvement of RBD symptoms following continuous positive airway pressure therapy. Lack of therapy with clonazepam resulted in an increased risk of sleep related injuries. Synucleinopathy was frequently diagnosed, even in patients with mild severity or uncommon IRBD presentations (e.g., patients who reported sleeping well, onset triggered by a life event, nocturnal ambulation) indicating that the development of a neurodegenerative disease is independent of the clinical presentation of IRBD. We report the largest IRBD cohort observed in a single center to date and highlight frequent features that were not reported or not sufficiently emphasized in previous publications. Physicians should be aware of

  5. Rapid eye movement (REM sleep deprivation reduces rat frontal cortex acetylcholinesterase (EC 3.1.1.7 activity

    Directory of Open Access Journals (Sweden)

    Camarini R.

    1997-01-01

    Full Text Available Rapid eye movement (REM sleep deprivation induces several behavioral changes. Among these, a decrease in yawning behavior produced by low doses of cholinergic agonists is observed which indicates a change in brain cholinergic neurotransmission after REM sleep deprivation. Acetylcholinesterase (Achase controls acetylcholine (Ach availability in the synaptic cleft. Therefore, altered Achase activity may lead to a change in Ach availability at the receptor level which, in turn, may result in modification of cholinergic neurotransmission. To determine if REM sleep deprivation would change the activity of Achase, male Wistar rats, 3 months old, weighing 250-300 g, were deprived of REM sleep for 96 h by the flower-pot technique (N = 12. Two additional groups, a home-cage control (N = 6 and a large platform control (N = 6, were also used. Achase was measured in the frontal cortex using two different methods to obtain the enzyme activity. One method consisted of the obtention of total (900 g supernatant, membrane-bound (100,000 g pellet and soluble (100,000 g supernatant Achase, and the other method consisted of the obtention of a fraction (40,000 g pellet enriched in synaptic membrane-bound enzyme. In both preparations, REM sleep deprivation induced a significant decrease in rat frontal cortex Achase activity when compared to both home-cage and large platform controls. REM sleep deprivation induced a significant decrease of 16% in the membrane-bound Achase activity (nmol thiocholine formed min-1 mg protein-1 in the 100,000 g pellet enzyme preparation (home-cage group 152.1 ± 5.7, large platform group 152.7 ± 24.9 and REM sleep-deprived group 127.9 ± 13.8. There was no difference in the soluble enzyme activity. REM sleep deprivation also induced a significant decrease of 20% in the enriched synaptic membrane-bound Achase activity (home-cage group 126.4 ± 21.5, large platform group 127.8 ± 20.4, REM sleep-deprived group 102.8 ± 14.2. Our results

  6. Dissociating the contributions of slow-wave sleep and rapid eye movement sleep to emotional item and source memory.

    Science.gov (United States)

    Groch, S; Zinke, K; Wilhelm, I; Born, J

    2015-07-01

    Sleep benefits the consolidation of emotional memories, and this influence is commonly attributed to the rapid eye movement (REM) stage of sleep. However, the contributions of sleep stages to memory for an emotional episode may differ for the event per se (i.e., item memory), and the context in which it occurred (source memory). Here, we examined the effects of slow wave sleep (SWS) and REM sleep on the consolidation of emotionally negative and neutral item (picture recognition) and source memory (recall of picture-location and picture-frame color association) in humans. In Study 1, the participants (n=18) learned 48 negative and 48 neutral pictures which were presented at specific locations and preceded by colored frames that had to be associated with the picture. In a within-subject design, learning was either followed by a 3-h early-night SWS-rich or by a late-night REM sleep-rich retention interval, then retrieval was tested. Only after REM-rich sleep, and not after SWS-rich sleep, was there a significant emotional enhancement, i.e., a significantly superior retention of emotional over neutral pictures. On the other hand, after SWS-rich sleep the retention of picture-frame color associations was better than after REM-rich sleep. However, this benefit was observed only for neutral pictures; and it was completely absent for the emotional pictures. To examine whether this absent benefit reflected a suppressive effect of emotionality on associations of minor task relevance, in Study 2 we manipulated the relevance of the picture-frame color association by combining it with information about monetary reward, following otherwise comparable procedures. Here, rewarded picture-frame color associations were equally well retained over SWS-rich early sleep no matter if the frames were associated with emotional or neutral pictures. Results are consistent with the view that REM sleep favors the emotional enhancement of item memory whereas SWS appears to contribute primarily

  7. Borehole tool outrigger arm displacement control mechanism

    International Nuclear Information System (INIS)

    Lee, A.G.

    1985-01-01

    As the outrigger arms of a borehole logging tool are flexed inwardly and outwardly according to the diameter of the borehole opening through which they pass, the corresponding axial displacements of the ends of the arms are controlled to determine the axial positions of the arms relative to the tool. Specifically, as the arm ends move, they are caused to rotate by a cam mechanism. The stiffness of the arms causes the arm ends to rotate in unison, and the exact positions of the arms on the tool are then controlled by the differential movements of the arm ends in the cams

  8. Octopus-inspired multi-arm robotic swimming.

    Science.gov (United States)

    Sfakiotakis, M; Kazakidi, A; Tsakiris, D P

    2015-05-13

    The outstanding locomotor and manipulation characteristics of the octopus have recently inspired the development, by our group, of multi-functional robotic swimmers, featuring both manipulation and locomotion capabilities, which could be of significant engineering interest in underwater applications. During its little-studied arm-swimming behavior, as opposed to the better known jetting via the siphon, the animal appears to generate considerable propulsive thrust and rapid acceleration, predominantly employing movements of its arms. In this work, we capture the fundamental characteristics of the corresponding complex pattern of arm motion by a sculling profile, involving a fast power stroke and a slow recovery stroke. We investigate the propulsive capabilities of a multi-arm robotic system under various swimming gaits, namely patterns of arm coordination, which achieve the generation of forward, as well as backward, propulsion and turning. A lumped-element model of the robotic swimmer, which considers arm compliance and the interaction with the aquatic environment, was used to study the characteristics of these gaits, the effect of various kinematic parameters on propulsion, and the generation of complex trajectories. This investigation focuses on relatively high-stiffness arms. Experiments employing a compliant-body robotic prototype swimmer with eight compliant arms, all made of polyurethane, inside a water tank, successfully demonstrated this novel mode of underwater propulsion. Speeds of up to 0.26 body lengths per second (approximately 100 mm s(-1)), and propulsive forces of up to 3.5 N were achieved, with a non-dimensional cost of transport of 1.42 with all eight arms and of 0.9 with only two active arms. The experiments confirmed the computational results and verified the multi-arm maneuverability and simultaneous object grasping capability of such systems.

  9. Arm Pain

    Science.gov (United States)

    ... be a sign of a heart attack. Seek emergency treatment if you have: Arm, shoulder or back ... http://www.mayoclinic.org/symptoms/arm-pain/basics/definition/SYM-20050870 . Mayo Clinic Footer Legal Conditions and ...

  10. The dream-lag effect: selective processing of personally significant events during Rapid Eye Movement sleep, but not during Slow Wave Sleep

    OpenAIRE

    van Rijn, E.; Eichenlaub, J.-B.; Lewis, Penelope A.; Walker, M.P.; Gaskell, M.G.; Malinowski, J.E.; Blagrove, M.

    2015-01-01

    Incorporation of details from waking life events into Rapid Eye Movement (REM) sleep dreams has been found to be highest on the night after, and then 5-7 nights after events (termed, respectively, the day-residue and dream-lag effects). In experiment 1, 44 participants kept a daily log for 10. days, reporting major daily activities (MDAs), personally significant events (PSEs), and major concerns (MCs). Dream reports were collected from REM and Slow Wave Sleep (SWS) in the laboratory, or from ...

  11. Single motor unit firing behaviour in the right trapezius muscle during rapid movement of right or left index finger.

    Directory of Open Access Journals (Sweden)

    Karen eSøgaard

    2014-11-01

    Full Text Available Computer work is associated with low level sustained activity in the trapezius muscle that may cause myalgia. The activity may be attention related or part of a general multijoint motor program providing stabilization of the shoulder girdle for precise finger manipulation. This study examines single motor unit (MU firing pattern in the right trapezius muscle during fast movements of ipsi or contralateral index finger. Modulated firing rate would support a general multi joint motor program, while a generally increased and continuous firing rate would support attention related activation. 12 healthy female subjects were seated at a computer work place with elbows and forearms supported. Ten double clicks (DC were performed with right and left index finger on a computer mouse instrumented with a trigger.Surface EMG was recorded from right and left trapezius muscle. Intramuscular EMG was recorded with a quadripolar wire electrode in the right trapezius.Surface EMG was analysed as %MVE. The intramuscular EMG was decomposed into individual MU action potential trains. Instantaneous firing rate (IFR was calculated from inter-spike interval with ISI shorter than 20 ms defined as doublets. IFR was averaged across 10 DC to show IFR modulation.Surface EMG in both right and left trapezius was 1.8-2.5%MVE. During right hand DC a total of 32 MUs were identified. Four subjects showed no activity. Four showed MU activity with weak or no variations related to the timing of DC. Four subjects showed large modulation in IFR with temporal relation to DC. During left hand DC 15 MUs were identified in 4 subjects, for two of the subjects with IFR modulations related to DC. Doublets was found as an integrated part of MU activation in the trapezius muscle and for one subject temporarily related to DC. In conclusion, DC with ipsi- and contralateral fast movements of the index finger was found to evoke biomechanically as well as attention related activity pattern in the

  12. Neuromuscular control of the point to point and oscillatory movements of a sagittal arm with the actor-critic reinforcement learning method.

    Science.gov (United States)

    Golkhou, Vahid; Parnianpour, Mohamad; Lucas, Caro

    2005-04-01

    In this study, we have used a single link system with a pair of muscles that are excited with alpha and gamma signals to achieve both point to point and oscillatory movements with variable amplitude and frequency.The system is highly nonlinear in all its physical and physiological attributes. The major physiological characteristics of this system are simultaneous activation of a pair of nonlinear muscle-like-actuators for control purposes, existence of nonlinear spindle-like sensors and Golgi tendon organ-like sensor, actions of gravity and external loading. Transmission delays are included in the afferent and efferent neural paths to account for a more accurate representation of the reflex loops.A reinforcement learning method with an actor-critic (AC) architecture instead of middle and low level of central nervous system (CNS), is used to track a desired trajectory. The actor in this structure is a two layer feedforward neural network and the critic is a model of the cerebellum. The critic is trained by state-action-reward-state-action (SARSA) method. The critic will train the actor by supervisory learning based on the prior experiences. Simulation studies of oscillatory movements based on the proposed algorithm demonstrate excellent tracking capability and after 280 epochs the RMS error for position and velocity profiles were 0.02, 0.04 rad and rad/s, respectively.

  13. Contrasting expressions of aggressive behavior released by lesions of the central nucleus of the amygdala during wakefulness and rapid eye movement sleep without atonia in cats.

    Science.gov (United States)

    Zagrodzka, J; Hedberg, C E; Mann, G L; Morrison, A R

    1998-06-01

    Whether damage to the central nucleus of the amygdala (Ace) contributes to the predatorylike attack sometimes observed in rapid eye movement sleep without atonia (REM-A), created in cats by bilateral pontine lesions, was examined. Such lesions eliminate REM sleep skeletal muscle atonia and release elaborate behavior. Unilateral damage to the Ace alone increased affective defensive aggressive behavior toward humans and conspecifics without altering predatory behavior in wakefulness. Pontine lesions added at loci normally not leading to aggression induced predatorylike attacks in REM-A as well as the waking affective defense. Alterations of autonomic activity, the absence of relevant environmental stimuli in REM-A, or both may explain the state-related differences.

  14. Broken Arm

    Science.gov (United States)

    ... of falling — including football, soccer, gymnastics, skiing and skateboarding — also increases the risk of a broken arm. ... for high-risk activities, such as in-line skating, snowboarding, rugby and football. Don't smoke. Smoking ...

  15. PHENIX Muon Arms

    International Nuclear Information System (INIS)

    Akikawa, H.; Al-Jamel, A.; Archuleta, J.B.; Archuleta, J.R.; Armendariz, R.; Armijo, V.; Awes, T.C.; Baldisseri, A.; Barker, A.B.; Barnes, P.D.; Bassalleck, B.; Batsouli, S.; Behrendt, J.; Bellaiche, F.G.; Bland, A.W.; Bobrek, M.; Boissevain, J.G.; Borel, H.; Brooks, M.L.; Brown, A.W.; Brown, D.S.; Bruner, N.; Cafferty, M.M.; Carey, T.A.; Chai, J.-S.; Chavez, L.L.; Chollet, S.; Choudhury, R.K.; Chung, M.S.; Cianciolo, V.; Clark, D.J.; Cobigo, Y.; Dabrowski, C.M.; Debraine, A.; DeMoss, J.; Dinesh, B.V.; Drachenberg, J.L.; Drapier, O.; Echave, M.A.; Efremenko, Y.V.; En'yo, H.; Fields, D.E.; Fleuret, F.; Fried, J.; Fujisawa, E.; Funahashi, H.; Gadrat, S.; Gastaldi, F.; Gee, T.F.; Glenn, A.; Gogiberidze, G.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Hance, R.H.; Hart, G.W.; Hayashi, N.; Held, S.; Hicks, J.S.; Hill, J.C.; Hoade, R.; Hong, B.; Hoover, A.; Horaguchi, T.; Hunter, C.T.; Hurst, D.E.; Ichihara, T.; Imai, K.; Isenhower, L.D.L. Davis; Isenhower, L.D.L. Donald; Ishihara, M.; Jang, W.Y.; Johnson, J.; Jouan, D.; Kamihara, N.; Kamyshkov, Y.; Kang, J.H.; Kapoor, S.S.; Kim, D.J.; Kim, D.-W.; Kim, G.-B.; Kinnison, W.W.; Klinksiek, S.; Kluberg, L.; Kobayashi, H.; Koehler, D.; Kotchenda, L.; Kuberg, C.H.; Kurita, K.; Kweon, M.J.; Kwon, Y.; Kyle, G.S.; LaBounty, J.J.; Lajoie, J.G.; Lee, D.M.; Lee, S.; Leitch, M.J.; Li, Z.; Liu, M.X.; Liu, X.; Liu, Y.; Lockner, E.; Lopez, J.D.; Mao, Y.; Martinez, X.B.; McCain, M.C.; McGaughey, P.L.; Mioduszewski, S.; Mischke, R.E.; Mohanty, A.K.; Montoya, B.C.; Moss, J.M.; Murata, J.; Murray, M.M.; Nagle, J.L.; Nakada, Y.; Newby, J.; Obenshain, F.; Palounek, A.P.T.; Papavassiliou, V.; Pate, S.F.; Plasil, F.; Pope, K.; Qualls, J.M.; Rao, G.; Read, K.F.; Robinson, S.H.; Roche, G.; Romana, A.; Rosnet, P.; Roth, R.; Saito, N.; Sakuma, T.; Sandhoff, W.F.; Sanfratello, L.; Sato, H.D.; Savino, R.; Sekimoto, M.; Shaw, M.R.; Shibata, T.-A.; Sim, K.S.; Skank, H.D.; Smith, D.E.; Smith, G.D.; Sondheim, W.E.; Sorensen, S.; Staley, F.; Stankus, P.W.; Steffens, S.; Stein, E.M.; Stepanov, M.; Stokes, W.; Sugioka, M.; Sun, Z.; Taketani, A.; Taniguchi, E.; Tepe, J.D.; Thornton, G.W.; Tian, W.; Tojo, J.; Torii, H.; Towell, R.S.; Tradeski, J.; Vassent, M.; Velissaris, C.; Villatte, L.; Wan, Y.; Watanabe, Y.; Watkins, L.C.; Whitus, B.R.; Williams, C.; Willis, P.S.; Wong-Swanson, B.G.; Yang, Y.; Yoneyama, S.; Young, G.R.; Zhou, S.

    2003-01-01

    The PHENIX Muon Arms detect muons at rapidities of |y|=(1.2-2.4) with full azimuthal acceptance. Each muon arm must track and identify muons and provide good rejection of pions and kaons (∼10 -3 ). In order to accomplish this we employ a radial field magnetic spectrometer with precision tracking (Muon Tracker) followed by a stack of absorber/low resolution tracking layers (Muon Identifier). The design, construction, testing and expected run parameters of both the muon tracker and the muon identifier are described

  16. PHENIX Muon Arms

    Energy Technology Data Exchange (ETDEWEB)

    Akikawa, H.; Al-Jamel, A.; Archuleta, J.B.; Archuleta, J.R.; Armendariz, R.; Armijo, V.; Awes, T.C.; Baldisseri, A.; Barker, A.B.; Barnes, P.D.; Bassalleck, B.; Batsouli, S.; Behrendt, J.; Bellaiche, F.G.; Bland, A.W.; Bobrek, M.; Boissevain, J.G.; Borel, H.; Brooks, M.L.; Brown, A.W.; Brown, D.S.; Bruner, N.; Cafferty, M.M.; Carey, T.A.; Chai, J.-S.; Chavez, L.L.; Chollet, S.; Choudhury, R.K.; Chung, M.S.; Cianciolo, V.; Clark, D.J.; Cobigo, Y.; Dabrowski, C.M.; Debraine, A.; DeMoss, J.; Dinesh, B.V.; Drachenberg, J.L.; Drapier, O.; Echave, M.A.; Efremenko, Y.V.; En' yo, H.; Fields, D.E.; Fleuret, F.; Fried, J.; Fujisawa, E.; Funahashi, H.; Gadrat, S.; Gastaldi, F.; Gee, T.F.; Glenn, A.; Gogiberidze, G.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Hance, R.H.; Hart, G.W.; Hayashi, N.; Held, S.; Hicks, J.S.; Hill, J.C.; Hoade, R.; Hong, B.; Hoover, A.; Horaguchi, T.; Hunter, C.T.; Hurst, D.E.; Ichihara, T.; Imai, K.; Isenhower, L.D.L. Davis; Isenhower, L.D.L. Donald; Ishihara, M.; Jang, W.Y.; Johnson, J.; Jouan, D.; Kamihara, N.; Kamyshkov, Y.; Kang, J.H.; Kapoor, S.S.; Kim, D.J.; Kim, D.-W.; Kim, G.-B.; Kinnison, W.W.; Klinksiek, S.; Kluberg, L.; Kobayashi, H.; Koehler, D.; Kotchenda, L.; Kuberg, C.H.; Kurita, K.; Kweon, M.J.; Kwon, Y.; Kyle, G.S.; LaBounty, J.J.; Lajoie, J.G.; Lee, D.M.; Lee, S.; Leitch, M.J.; Li, Z.; Liu, M.X.; Liu, X.; Liu, Y.; Lockner, E.; Lopez, J.D.; Mao, Y.; Martinez, X.B.; McCain, M.C.; McGaughey, P.L.; Mioduszewski, S.; Mischke, R.E.; Mohanty, A.K.; Montoya, B.C.; Moss, J.M.; Murata, J.; Murray, M.M.; Nagle, J.L.; Nakada, Y.; Newby, J.; Obenshain, F.; Palounek, A.P.T.; Papavassiliou, V.; Pate, S.F.; Plasil, F.; Pope, K.; Qualls, J.M.; Rao, G.; Read, K.F. E-mail: readkf@ornl.gov; Robinson, S.H.; Roche, G.; Romana, A.; Rosnet, P.; Roth, R.; Saito, N.; Sakuma, T.; Sandhoff, W.F.; Sanfratello, L.; Sato, H.D.; Savino, R.; Sekimoto, M.; Shaw, M.R.; Shibata, T.-A.; Sim, K.S.; Skank, H.D.; Smith, D.E.; Smith, G.D. [and others

    2003-03-01

    The PHENIX Muon Arms detect muons at rapidities of |y|=(1.2-2.4) with full azimuthal acceptance. Each muon arm must track and identify muons and provide good rejection of pions and kaons ({approx}10{sup -3}). In order to accomplish this we employ a radial field magnetic spectrometer with precision tracking (Muon Tracker) followed by a stack of absorber/low resolution tracking layers (Muon Identifier). The design, construction, testing and expected run parameters of both the muon tracker and the muon identifier are described.

  17. The King-Devick (K-D) test of rapid eye movements: a bedside correlate of disability and quality of life in MS.

    Science.gov (United States)

    Moster, Stephen; Wilson, James A; Galetta, Steven L; Balcer, Laura J

    2014-08-15

    We investigated the King-Devick (K-D) test of rapid number naming as a visual performance measure in a cohort of patients with multiple sclerosis (MS). In this cross-sectional study, 81 patients with MS and 20 disease-free controls from an ongoing study of visual outcomes underwent K-D testing. A test of rapid number naming, K-D requires saccadic eye movements as well as intact vision, attention and concentration. To perform the K-D test, participants are asked to read numbers aloud as quickly as possible from three test cards; the sum of the three test card times in seconds constitutes the summary score. High-contrast visual acuity (VA), low-contrast letter acuity (1.25% and 2.5% levels), retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT), MS Functional Composite (MSFC) and vision-specific quality of life (QOL) measures (25-Item NEI Visual Functioning Questionnaire [NEI-VFQ-25] and 10-Item Neuro-Ophthalmic Supplement) were also assessed. K-D time scores in the MS cohort (total time to read the three test cards) were significantly higher (worse) compared to those for disease-free controls (P=0.003, linear regression, accounting for age). Within the MS cohort, higher K-D scores were associated with worse scores for the NEI-VFQ-25 composite (Paccounting for age and within-patient, inter-eye correlations). Patients with a history of optic neuritis (ON) had increased (worse) K-D scores. Patients who classified their work disability status as disabled (receiving disability pension) did worse on K-D testing compared to those working full-time (P=0.001, accounting for age). The K-D test, a work disability as well as structural changes as measured by OCT imaging. History of ON and abnormal binocular acuities were associated with worse K-D scores, suggesting that abnormalities detected by K-D may go along with afferent dysfunction in MS patients. A brief test that requires saccadic eye movements, K-D should be considered for future MS trials as

  18. Trunk Muscle Activation at the Initiation and Braking of Bilateral Shoulder Flexion Movements of Different Amplitudes.

    Directory of Open Access Journals (Sweden)

    M Eriksson Crommert

    Full Text Available The aim of this study was to investigate if trunk muscle activation patterns during rapid bilateral shoulder flexions are affected by movement amplitude. Eleven healthy males performed shoulder flexion movements starting from a position with arms along sides (0° to either 45°, 90° or 180°. EMG was measured bilaterally from transversus abdominis (TrA, obliquus internus (OI with intra-muscular electrodes, and from rectus abdominis (RA, erector spinae (ES and deltoideus with surface electrodes. 3D kinematics was recorded and inverse dynamics was used to calculate the reactive linear forces and torque about the shoulders and the linear and angular impulses. The sequencing of trunk muscle onsets at the initiation of arm movements was the same across movement amplitudes with ES as the first muscle activated, followed by TrA, RA and OI. All arm movements induced a flexion angular impulse about the shoulders during acceleration that was reversed during deceleration. Increased movement amplitude led to shortened onset latencies of the abdominal muscles and increased level of activation in TrA and ES. The activation magnitude of TrA was similar in acceleration and deceleration where the other muscles were specific to acceleration or deceleration. The findings show that arm movements need to be standardized when used as a method to evaluate trunk muscle activation patterns and that inclusion of the deceleration of the arms in the analysis allow the study of the relationship between trunk muscle activation and direction of perturbing torque during one and the same arm movement.

  19. Quantitative assessment of isolated rapid eye movement (REM) sleep without atonia without clinical REM sleep behavior disorder: clinical and research implications.

    Science.gov (United States)

    Sasai-Sakuma, Taeko; Frauscher, Birgit; Mitterling, Thomas; Ehrmann, Laura; Gabelia, David; Brandauer, Elisabeth; Inoue, Yuichi; Poewe, Werner; Högl, Birgit

    2014-09-01

    Rapid eye movement (REM) sleep without atonia (RWA) is observed in some patients without a clinical history of REM sleep behavior disorder (RBD). It remains unknown whether these patients meet the refined quantitative electromyographic (EMG) criteria supporting a clinical RBD diagnosis. We quantitatively evaluated EMG activity and investigated its overnight distribution in patients with isolated qualitative RWA. Fifty participants with an incidental polysomnographic finding of RWA (isolated qualitative RWA) were included. Tonic, phasic, and 'any' EMG activity during REM sleep on PSG were quantified retrospectively. Referring to the quantitative cut-off values for a polysomnographic diagnosis of RBD, 7/50 (14%) and 6/50 (12%) of the patients showed phasic and 'any' EMG activity in the mentalis muscle above the respective cut-off values. No patient was above the cut-off value for tonic EMG activity or phasic EMG activity in the anterior tibialis muscles. Patients with RWA above the cut-off value showed higher amounts of RWA during later REM sleep periods. This is the first study showing that some subjects with incidental RWA meet the refined quantitative EMG criteria for a diagnosis of RBD. Future longitudinal studies must investigate whether this subgroup with isolated qualitative RWA is at an increased risk of developing fully expressed RBD and/or neurodegenerative disease. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Essential roles of GABA transporter-1 in controlling rapid eye movement sleep and in increased slow wave activity after sleep deprivation.

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    Xin-Hong Xu

    Full Text Available GABA is the major inhibitory neurotransmitter in the mammalian central nervous system that has been strongly implicated in the regulation of sleep. GABA transporter subtype 1 (GAT1 constructs high affinity reuptake sites for GABA and regulates GABAergic transmission in the brain. However, the role of GAT1 in sleep-wake regulation remains elusive. In the current study, we characterized the spontaneous sleep-wake cycle and responses to sleep deprivation in GAT1 knock-out (KO mice. GAT1 KO mice exhibited dominant theta-activity and a remarkable reduction of EEG power in low frequencies across all vigilance stages. Under baseline conditions, spontaneous rapid eye movement (REM sleep of KO mice was elevated both during the light and dark periods, and non-REM (NREM sleep was reduced during the light period only. KO mice also showed more state transitions from NREM to REM sleep and from REM sleep to wakefulness, as well as more number of REM and NREM sleep bouts than WT mice. During the dark period, KO mice exhibited more REM sleep bouts only. Six hours of sleep deprivation induced rebound increases in NREM and REM sleep in both genotypes. However, slow wave activity, the intensity component of NREM sleep was briefly elevated in WT mice but remained completely unchanged in KO mice, compared with their respective baselines. These results indicate that GAT1 plays a critical role in the regulation of REM sleep and homeostasis of NREM sleep.

  1. Abnormal Gray Matter Shape, Thickness, and Volume in the Motor Cortico-Subcortical Loop in Idiopathic Rapid Eye Movement Sleep Behavior Disorder: Association with Clinical and Motor Features.

    Science.gov (United States)

    Rahayel, Shady; Postuma, Ronald B; Montplaisir, Jacques; Bedetti, Christophe; Brambati, Simona; Carrier, Julie; Monchi, Oury; Bourgouin, Pierre-Alexandre; Gaubert, Malo; Gagnon, Jean-François

    2018-02-01

    Idiopathic rapid eye movement sleep behavior disorder (iRBD) is a major risk factor for Parkinson's disease and dementia with Lewy bodies. Anatomical gray matter abnormalities in the motor cortico-subcortical loop areas remain under studied in iRBD patients. We acquired T1-weighted images and administrated quantitative motor tasks in 41 patients with polysomnography-confirmed iRBD and 41 healthy subjects. Cortical thickness and voxel-based morphometry (VBM) analyses were performed to investigate local cortical thickness and gray matter volume changes, vertex-based shape analysis to investigate shape of subcortical structures, and structure-based volumetric analyses to investigate volumes of subcortical and brainstem structures. Cortical thickness analysis revealed thinning in iRBD patients in bilateral medial superior frontal, orbitofrontal, anterior cingulate cortices, and the right dorsolateral primary motor cortex. VBM results showed lower gray matter volume in iRBD patients in the frontal lobes, anterior cingulate gyri, and caudate nucleus. Shape analysis revealed extensive surface contraction in the external and internal segments of the left pallidum. Clinical and motor impaired features in iRBD were associated with anomalies of the motor cortico-subcortical loop. In summary, iRBD patients showed numerous gray matter structural abnormalities in the motor cortico-subcortical loop, which are associated with lower motor performance and clinical manifestations of iRBD. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Sixty-five radiation hybrids for the short arm of human chromosome 6: their value as a mapping panel and as a source for rapid isolation of new probes using repeat element-mediated PCR

    International Nuclear Information System (INIS)

    Zoghbi, H.Y.; McCall, A.E.; LeBorgne-Demarquoy, F.

    1991-01-01

    We have used an irradiation and fusion procedure to generate somatic cell hybrids that retain fragments of the short arm of human chromosome 6 (6p). To identify hybrids retaining human material, we performed repeat element-mediated PCR on crude lysates of cells from individual clones. Sixty-five hybrids were shown to contain human material and fifty of those contained one or more 6p-specific probes. Detailed characterization of these hybrids identified a subset that divides 6p into ten mapping intervals. Using repeat element-mediated PCR, we were able to isolate and map 61 new DNA fragments from specific regions of 6p. Fifteen of these fragments were used to screen for restriction fragment length polymorphisms (RFLPs), and nine identified RFLPs with one or more enzymes. The radiation hybrids described in this study provide a valuable resource for high-resolution mapping of 6p and for the rapid isolation of region-specific markers

  3. The lateral paragigantocellular nucleus modulates parasympathetic cardiac neurons: a mechanism for rapid eye movement sleep-dependent changes in heart rate.

    Science.gov (United States)

    Dergacheva, Olga; Wang, Xin; Lovett-Barr, Mary R; Jameson, Heather; Mendelowitz, David

    2010-08-01

    Rapid eye movement (REM) sleep is generally associated with a withdrawal of parasympathetic activity and heart rate increases; however, episodic vagally mediated heart rate decelerations also occur during REM sleep. This alternating pattern of autonomic activation provides a physiological basis for REM sleep-induced cardiac arrhythmias. Medullary neurons within the lateral paragigantocellular nucleus (LPGi) are thought to be active after REM sleep recovery and play a role in REM sleep control. In proximity to the LPGi are parasympathetic cardiac vagal neurons (CVNs) within the nucleus ambiguus (NA), which are critical for controlling heart rate. This study examined brain stem pathways that may mediate REM sleep-related reductions in parasympathetic cardiac activity. Electrical stimulation of the LPGi evoked inhibitory GABAergic postsynaptic currents in CVNs in an in vitro brain stem slice preparation in rats. Because brain stem cholinergic mechanisms are involved in REM sleep regulation, we also studied the role of nicotinic neurotransmission in modulation of GABAergic pathway from the LGPi to CVNs. Application of nicotine diminished the GABAergic responses evoked by electrical stimulation. This inhibitory effect of nicotine was prevented by the alpha7 nicotinic receptor antagonist alpha-bungarotoxin. Moreover, hypoxia/hypercapnia (H/H) diminished LPGi-evoked GABAergic current in CVNs, and this inhibitory effect was also prevented by alpha-bungarotoxin. In conclusion, stimulation of the LPGi evokes an inhibitory pathway to CVNs, which may constitute a mechanism for the reduced parasympathetic cardiac activity and increase in heart rate during REM sleep. Inhibition of this pathway by nicotinic receptor activation and H/H may play a role in REM sleep-related and apnea-associated bradyarrhythmias.

  4. White and gray matter abnormalities in idiopathic rapid eye movement sleep behavior disorder: a diffusion-tensor imaging and voxel-based morphometry study.

    Science.gov (United States)

    Scherfler, Christoph; Frauscher, Birgit; Schocke, Michael; Iranzo, Alex; Gschliesser, Viola; Seppi, Klaus; Santamaria, Joan; Tolosa, Eduardo; Högl, Birgit; Poewe, Werner

    2011-02-01

    We applied diffusion-tensor imaging (DTI) including measurements of mean diffusivity (MD), a parameter of brain tissue integrity, fractional anisotropy (FA), a parameter of neuronal fiber integrity, as well as voxel-based morphometry (VBM), a measure of gray and white matter volume, to detect brain tissue changes in patients with idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD). Magnetic resonance imaging (MRI) was performed in 26 patients with iRBD (mean disease duration, 9.2 ± 6.4 years) and 14 age-matched healthy control subjects. Statistical parametric mapping (SPM) was applied to objectively identify focal changes of MRI parameters throughout the entire brain volume. SPM localized significant decreases of FA in the tegmentum of the midbrain and rostral pons and increases of MD within the pontine reticular formation overlapping with a cluster of decreased FA in the midbrain (p < 0.001). VBM revealed increases of gray matter densities in both hippocampi of iRBD patients (p < 0.001). The observed changes in the pontomesencephalic brainstem localized 2 areas harboring key neuronal circuits believed to be involved in the regulation of REM sleep and overlap with areas of structural brainstem damage causing symptomatic RBD in humans. Bilateral increases in gray matter density of the hippocampus suggest functional neuronal reorganization in this brain area in iRBD. This study indicates that DTI detects distinct structural brainstem tissue abnormalities in iRBD in the regions where REM is modulated. Further studies should explore the relationship between MRI pathology and the risk of patients with iRBD of developing alpha-synuclein-related neurodegenerative diseases like Parkinson disease. Copyright © 2010 American Neurological Association.

  5. Dreaming furiously? A sleep laboratory study on the dream content of people with Parkinson's disease and with or without rapid eye movement sleep behavior disorder.

    Science.gov (United States)

    Valli, Katja; Frauscher, Birgit; Peltomaa, Taina; Gschliesser, Viola; Revonsuo, Antti; Högl, Birgit

    2015-03-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) has been related to altered, action-filled, vivid, and aggressive dream content, but research comparing the possible differences in dreams of Parkinson's disease (PD) patients with and without RBD is scarce. The dream content of PD patients with and without RBD was analyzed with specific focus on action-filledness, vividness, emotional valence, and threats. A total of 69 REM and NREM dream reports were collected in the sleep laboratory, 37 from nine PD patients with RBD and 32 from six PD patients without RBD. A content analysis of (1) action-filledness (actions and environmental events); (2) vividness (emotions and cognitive activity); (3) intensity of actions, events and emotions; (4) emotional valence, and (5) threatening events was performed on the transcripts. Altogether 563 dream elements expressing action-filledness and vividness were found. There were no significant between-group differences in the number or distribution of elements reflecting action-filledness or vividness, emotional valence or threats. In within-group analyses, PD patients with RBD had significantly more negative compared to positive dreams (p = 0.012) and compared to PD patients without RBD, a tendency to have more intense actions in their dreams (p = 0.066). Based on the results of this study, there are no major between-group differences in the action-filledness, vividness, or threat content of dreams of PD patients with and without RBD. However, within-group analyses revealed that dreams were more often negatively than positively toned in PD patients with RBD. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. The dream-lag effect: Selective processing of personally significant events during Rapid Eye Movement sleep, but not during Slow Wave Sleep.

    Science.gov (United States)

    van Rijn, E; Eichenlaub, J-B; Lewis, P A; Walker, M P; Gaskell, M G; Malinowski, J E; Blagrove, M

    2015-07-01

    Incorporation of details from waking life events into Rapid Eye Movement (REM) sleep dreams has been found to be highest on the night after, and then 5-7 nights after events (termed, respectively, the day-residue and dream-lag effects). In experiment 1, 44 participants kept a daily log for 10 days, reporting major daily activities (MDAs), personally significant events (PSEs), and major concerns (MCs). Dream reports were collected from REM and Slow Wave Sleep (SWS) in the laboratory, or from REM sleep at home. The dream-lag effect was found for the incorporation of PSEs into REM dreams collected at home, but not for MDAs or MCs. No dream-lag effect was found for SWS dreams, or for REM dreams collected in the lab after SWS awakenings earlier in the night. In experiment 2, the 44 participants recorded reports of their spontaneously recalled home dreams over the 10 nights following the instrumental awakenings night, which thus acted as a controlled stimulus with two salience levels, high (sleep lab) and low (home awakenings). The dream-lag effect was found for the incorporation into home dreams of references to the experience of being in the sleep laboratory, but only for participants who had reported concerns beforehand about being in the sleep laboratory. The delayed incorporation of events from daily life into dreams has been proposed to reflect REM sleep-dependent memory consolidation. However, an alternative emotion processing or emotional impact of events account, distinct from memory consolidation, is supported by the finding that SWS dreams do not evidence the dream-lag effect. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Slow oscillating transcranial direct current stimulation during non-rapid eye movement sleep improves behavioral inhibition in attention-deficit/ hyperactivity disorder

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    Manuel Tobias Munz

    2015-08-01

    Full Text Available Background: Behavioral inhibition, which is a later-developing executive function (EF and anatomically located in prefrontal areas, is impaired in attention-deficit and hyperactivity disorder (ADHD. While optimal EFs have been shown to depend on efficient sleep in healthy subjects, the impact of sleep problems, frequently reported in ADHD, remains elusive. Findings of macroscopic sleep changes in ADHD are inconsistent, but there is emerging evidence for distinct microscopic changes with a focus on prefrontal cortical regions and non-rapid eye movement (non-REM slow-wave sleep. Recently, slow oscillations (SO during non-REM sleep were found to be less functional and, as such, may be involved in sleep-dependent memory impairments in ADHD. Objective: By augmenting slow-wave power through bilateral, slow oscillating transcranial direct current stimulation (so-tDCS, frequency = 0.75 Hz during non-REM sleep, we aimed to improve daytime behavioral inhibition in children with ADHD. Methods: 14 boys (10-14 yrs diagnosed with ADHD were included. In a randomized, double-blind, cross-over design, patients received so-tDCS either in the first or in the second experimental sleep night. Inhibition control was assessed with a visuomotor go/no-go task. Intrinsic alertness was assessed with a simple stimulus response task. To control for visuomotor performance, motor memory was assessed with a finger sequence tapping task. Results: SO-power was enhanced during early non-REM sleep, accompanied by slowed reaction times and decreased standard deviations of reaction times, in the go/no-go task after so-tDCS. In contrast, intrinsic alertness and motor memory performance were not improved by so-tDCS. Conclusion: Since behavioral inhibition but not intrinsic alertness or motor memory was improved by so-tDCS, our results suggest that lateral prefrontal slow oscillations during sleep might play a specific role for executive functioning in ADHD.

  8. Blood RNA biomarkers in prodromal PARK4 and rapid eye movement sleep behavior disorder show role of complexin 1 loss for risk of Parkinson's disease

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    Suna Lahut

    2017-05-01

    Full Text Available Parkinson's disease (PD is a frequent neurodegenerative process in old age. Accumulation and aggregation of the lipid-binding SNARE complex component α-synuclein (SNCA underlies this vulnerability and defines stages of disease progression. Determinants of SNCA levels and mechanisms of SNCA neurotoxicity have been intensely investigated. In view of the physiological roles of SNCA in blood to modulate vesicle release, we studied blood samples from a new large pedigree with SNCA gene duplication (PARK4 mutation to identify effects of SNCA gain of function as potential disease biomarkers. Downregulation of complexin 1 (CPLX1 mRNA was correlated with genotype, but the expression of other Parkinson's disease genes was not. In global RNA-seq profiling of blood from presymptomatic PARK4 indviduals, bioinformatics detected significant upregulations for platelet activation, hemostasis, lipoproteins, endocytosis, lysosome, cytokine, Toll-like receptor signaling and extracellular pathways. In PARK4 platelets, stimulus-triggered degranulation was impaired. Strong SPP1, GZMH and PLTP mRNA upregulations were validated in PARK4. When analysing individuals with rapid eye movement sleep behavior disorder, the most specific known prodromal stage of general PD, only blood CPLX1 levels were altered. Validation experiments confirmed an inverse mutual regulation of SNCA and CPLX1 mRNA levels. In the 3′-UTR of the CPLX1 gene we identified a single nucleotide polymorphism that is significantly associated with PD risk. In summary, our data define CPLX1 as a PD risk factor and provide functional insights into the role and regulation of blood SNCA levels. The new blood biomarkers of PARK4 in this Turkish family might become useful for PD prediction.

  9. Effects of Optogenetic inhibition of BLA on Sleep Brief Optogenetic Inhibition of the Basolateral Amygdala in Mice Alters Effects of Stressful Experiences on Rapid Eye Movement Sleep.

    Science.gov (United States)

    Machida, Mayumi; Wellman, Laurie L; Fitzpatrick Bs, Mairen E; Hallum Bs, Olga; Sutton Bs, Amy M; Lonart, György; Sanford, Larry D

    2017-04-01

    Stressful events can directly produce significant alterations in subsequent sleep, in particular rapid eye movement sleep (REM); however, the neural mechanisms underlying the process are not fully known. Here, we investigated the role of the basolateral nuclei of the amygdala (BLA) in regulating the effects of stressful experience on sleep. We used optogenetics to briefly inhibit glutamatergic cells in BLA during the presentation of inescapable footshock (IS) and assessed effects on sleep, the acute stress response, and fear memory. c-Fos expression was also assessed in the amygdala and the medial prefrontal cortex (mPFC), both regions involved in coping with stress, and in brain stem regions implicated in the regulation of REM. Compared to control mice, peri-shock inhibition of BLA attenuated an immediate reduction in REM after IS and produced a significant overall increase in REM. Moreover, upon exposure to the shock context alone, mice receiving peri-shock inhibition of BLA during training showed increased REM without altered freezing (an index of fear memory) or stress-induced hyperthermia (an index of acute stress response). Inhibition of BLA during REM under freely sleeping conditions enhanced REM only when body temperature was high, suggesting the effect was influenced by stress. Peri-shock inhibition of BLA also led to elevated c-Fos expression in the central nucleus of the amygdala and mPFC and differentially altered c-Fos activity in the selected brain stem regions. Glutamatergic cells in BLA can modulate the effects of stress on REM and can mediate effects of fear memory on sleep that can be independent of behavioral fear. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  10. Picking Robot Arm Trajectory Planning Method

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    Zhang Zhiyong

    2014-01-01

    Full Text Available The picking robot arm is scheduled to complete picking tasks in the working space, to overcome the shaking vibration to improve the picking stability, its movement should follow specific consistence trajectory points. Usually we should give definite multiple feature picking points, map their inverse kinematics to the joint space, establish motion equation for the corresponding point in the joint space, then follow these equations motion for the interpolation on the joint so that we can meet the movement requirements. Trajectory planning is decisive significance for accuracy and stability of controlling robot arm. The key issue that picking arm complete picking task will be come true by trajectory planning, namely, robot arm track the desired trajectory. which based on kinematics and statics picking analysis in a joint space according to the requirements of picking tasks, and obtain the position and orientation for picking robot arm, study and calculate the theory of trajectory parameters timely.

  11. A neural tracking and motor control approach to improve rehabilitation of upper limb movements

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    Schmid Maurizio

    2008-02-01

    Full Text Available Abstract Background Restoration of upper limb movements in subjects recovering from stroke is an essential keystone in rehabilitative practices. Rehabilitation of arm movements, in fact, is usually a far more difficult one as compared to that of lower extremities. For these reasons, researchers are developing new methods and technologies so that the rehabilitative process could be more accurate, rapid and easily accepted by the patient. This paper introduces the proof of concept for a new non-invasive FES-assisted rehabilitation system for the upper limb, called smartFES (sFES, where the electrical stimulation is controlled by a biologically inspired neural inverse dynamics model, fed by the kinematic information associated with the execution of a planar goal-oriented movement. More specifically, this work details two steps of the proposed system: an ad hoc markerless motion analysis algorithm for the estimation of kinematics, and a neural controller that drives a synthetic arm. The vision of the entire system is to acquire kinematics from the analysis of video sequences during planar arm movements and to use it together with a neural inverse dynamics model able to provide the patient with the electrical stimulation patterns needed to perform the movement with the assisted limb. Methods The markerless motion tracking system aims at localizing and monitoring the arm movement by tracking its silhouette. It uses a specifically designed motion estimation method, that we named Neural Snakes, which predicts the arm contour deformation as a first step for a silhouette extraction algorithm. The starting and ending points of the arm movement feed an Artificial Neural Controller, enclosing the muscular Hill's model, which solves the inverse dynamics to obtain the FES patterns needed to move a simulated arm from the starting point to the desired point. Both position error with respect to the requested arm trajectory and comparison between curvature factors

  12. Control of octopus arm extension by a peripheral motor program.

    Science.gov (United States)

    Sumbre, G; Gutfreund, Y; Fiorito, G; Flash, T; Hochner, B

    2001-09-07

    For goal-directed arm movements, the nervous system generates a sequence of motor commands that bring the arm toward the target. Control of the octopus arm is especially complex because the arm can be moved in any direction, with a virtually infinite number of degrees of freedom. Here we show that arm extensions can be evoked mechanically or electrically in arms whose connection with the brain has been severed. These extensions show kinematic features that are almost identical to normal behavior, suggesting that the basic motor program for voluntary movement is embedded within the neural circuitry of the arm itself. Such peripheral motor programs represent considerable simplification in the motor control of this highly redundant appendage.

  13. Bowel Movement

    Science.gov (United States)

    A bowel movement is the last stop in the movement of food through your digestive tract. Your stool passes out of ... what you eat and drink. Sometimes a bowel movement isn't normal. Diarrhea happens when stool passes ...

  14. Polycythemia vera presenting with left hemichoreiform movements

    International Nuclear Information System (INIS)

    Mori, Tamiharu; Shimomura, Chikako; Ishibashi, Hiroshi; Tsujihata, Mitsuhiro; Nagataki, Shigenobu.

    1985-01-01

    A 65-year-old man developed abruptly choreiform movements involving the left face, arm and leg one day prior to admission. Physical examination revealed red face and palms, hyperemic conjunctivae and atrial fibrillations. Blood pressure was 168/90. Spleen was not palpable. Hemichoreiform movements of the left face and limbs were observed. There was no other neurological abnormalities. Laboratory studies showed RBC 880x10 4 , Hb 22.4g/dl, Hct 63%, WBC 8,100, platelets 22.9x10 4 , ESR 0mm/hr, RBC oxygen saturation 97%, serum iron 67 μg/dl, LDH 593 units, uric acid 14mg/dl, and erythropoietine (HI method) 19mIU/ml (normal 28-88). Bone marrow showed myeloid nucleated cell count 38.6x10 4 . ECG showed atrial fibrillations. Chest X-ray and scintigrams of liver and spleen were normal. CSF was normal. Brain CT scan on admission disclosed a low density area in right caudate nucleus. The choreiform movements were rapidly mitigated by venesection and by oral administration of haloperidol(3mg daily). There weeks after discontinuing haloperidol, the hemichorea returned. The routine hematology showed RBC 870x10 4 , Hb 19.8g/dl, Hct 62%, WBC 10,200, and plateret 37.4x10 4 . Another venesection reduced the chorea. Pipobroman was administered to control the polycythemia vera. He has been free of choreic movements thereafter. Choreiform movement is rarely observed in polycythemia vera. The pathogenesis is still unknown. The venous congestion, however, may play a role in this case because the choreic movements disappeared by venesection. (author)

  15. Simulation of Octopus Arm Based on Coupled CPGs

    Directory of Open Access Journals (Sweden)

    Juan Tian

    2015-01-01

    Full Text Available The octopus arm has attracted many researchers’ interests and became a research hot spot because of its amazing features. Several dynamic models inspired by an octopus arm are presented to realize the structure with a large number of degrees of freedom. The octopus arm is made of a soft material introducing high-dimensionality, nonlinearity, and elasticity, which makes the octopus arm difficult to control. In this paper, three coupled central pattern generators (CPGs are built and a 2-dimensional dynamic model of the octopus arm is presented to explore possible strategies of the octopus movement control. And the CPGs’ signals treated as activation are added on the ventral, dorsal, and transversal sides, respectively. The effects of the octopus arm are discussed when the parameters of the CPGs are changed. Simulations show that the octopus arm movements are mainly determined by the shapes of three CPGs’ phase diagrams. Therefore, some locomotion modes are supposed to be embedded in the neuromuscular system of the octopus arm. And the octopus arm movements can be achieved by modulating the parameters of the CPGs. The results are beneficial for researchers to understand the octopus movement further.

  16. The musculature of coleoid cephalopod arms and tentacles

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    William McKee Kier

    2016-02-01

    Full Text Available The regeneration of coleoid cephalopod arms and tentacles is a common occurrence, recognized since Aristotle. The complexity of the arrangement of the muscle and connective tissues of these appendages make them of great interest for research on regeneration. They lack rigid skeletal elements and consist of a three-dimensional array of muscle fibers, relying on a type of skeletal support system called a muscular hydrostat. Support and movement in the arms and tentacles depends on the fact that muscle tissue resists volume change. The basic principle of function is straightforward; because the volume of the appendage is essentially constant, a decrease in one dimension must result in an increase in another dimension. Since the muscle fibers are arranged in three mutually perpendicular directions, all three dimensions can be actively controlled and thus a remarkable diversity of movements and deformations can be produced. In the arms and tentacles of coleoids, three main muscle orientations are observed: 1 transverse muscle fibers arranged in planes perpendicular to the longitudinal axis; 2 longitudinal muscle fibers typically arranged in bundles parallel to the longitudinal axis; and 3 helical or obliquely arranged layers of muscle fibers, arranged in both right- and left-handed helixes. By selective activation of these muscle groups, elongation, shortening, bending, torsion and stiffening of the appendage can be produced. The predominant muscle fiber type is obliquely striated. Cross-striated fibers are found only in the transverse muscle mass of the prey capture tentacles of squid and cuttlefish. These fibers have unusually short myofilaments and sarcomeres, generating the high shortening velocity required for rapid elongation of the tentacles. It is likely that coleoid cephalopods use ultrastructural modifications rather than tissue-specific myosin isoforms to tune contraction velocities.

  17. Modified Constraint-Induced Movement Therapy combined with Bimanual Training (mCIMT-BiT) in children with unilateral spastic cerebral palsy: how are improvements in arm-hand use established?

    NARCIS (Netherlands)

    Aarts, P.B.M.; Jongerius, P.H.; Geerdink-van Nistelrooij, Y.A. van; Limbeek, J. van; Geurts, A.C.H.

    2011-01-01

    A recent randomized controlled trial indicated that modified Constraint-Induced Movement Therapy followed by Bimanual Training (mCIMT-BiT) is an effective intervention to improve spontaneous use of the affected upper limb in children with unilateral spastic cerebral palsy (CP). The present study

  18. Isolated effects of peripheral arm and central body cooling on arm performance.

    Science.gov (United States)

    Giesbrecht, G G; Wu, M P; White, M D; Johnston, C E; Bristow, G K

    1995-10-01

    Whole body cooling impairs manual arm performance. The independent contributions of local (peripheral) and/or whole body (central) cooling are not known. Therefore, a protocol was developed in which the arm and the rest of the body could be independently cooled. Biceps temperature (Tmus), at a depth of 20 mm, and esophageal temperature (Tes) were measured. Six subjects were immersed to the clavicles in a tank (body tank) of water under 3 conditions: 1) cold body-cold arm (CB-CA); 2) warm body-cold arm (WB-CA); and 3) cold body-warm arm (CB-WA). In the latter two conditions, subjects placed their dominant arm in a separate (arm) tank. Water temperature (Tw) in each tank was independently controlled. In conditions requiring cold body and/or cold arm, Tw in the appropriate tanks was 8 degrees C. In conditions requiring warm body and/or warm arm, Tw in the appropriate tanks was adjusted between 29 and 38 degrees C to maintain body/arm temperature at baseline values. A battery of 6 tests, requiring fine or gross motor movements, were performed immediately before immersion and after 15, 45, and 70 minutes of immersion. In CB-CA, Tes decreased from an average of 37.2 to 35.6 degrees C and Tmus decreased from 34.6 to 22.0 degrees C. In WB-CA, Tmus decreased to 18.1 degrees C (Tes = 37.1 degrees C), and in CB-WA, Tes decreased to 35.8 degrees C (Tmus = 34.5 degrees C). By the end of immersion, there were significant decrements (43-85%) in the performance of all tests in CB-CA and WB-CA (p body and/or the arm elicits large decrements in finger, hand and arm performance. The decrements are due almost entirely to the local effects of arm tissue cooling.

  19. Movement - uncoordinated

    Science.gov (United States)

    ... Loss of coordination; Coordination impairment; Ataxia; Clumsiness; Uncoordinated movement ... Smooth graceful movement requires a balance between different muscle groups. A part of the brain called the cerebellum manages this balance.

  20. JPRS Report Arms Control

    National Research Council Canada - National Science Library

    1993-01-01

    Table of Contents: (1) COMMONWEALTH OF INDEPENDENT STATES - (A) GENERAL Flaws in U.S.-Russian SSD Agreement Viewed, Khariton - Espionage Not Crucial in Soviet Nuclear Arms Development, Further on Espionage Role in Nuclear Arms Projects...

  1. Slope movements

    International Nuclear Information System (INIS)

    Wagner, P.

    2009-01-01

    On this poster some reasons of slope movements on the territory of the Slovak Republic are presented. Slope movements induced deterioration of land and forests, endangering of towns villages, and communications as well as hydro-engineering structures. Methods of preventing and stabilisation of slope movements are presented.

  2. Evolution of robotic arms.

    Science.gov (United States)

    Moran, Michael E

    2007-01-01

    The foundation of surgical robotics is in the development of the robotic arm. This is a thorough review of the literature on the nature and development of this device with emphasis on surgical applications. We have reviewed the published literature and classified robotic arms by their application: show, industrial application, medical application, etc. There is a definite trend in the manufacture of robotic arms toward more dextrous devices, more degrees-of-freedom, and capabilities beyond the human arm. da Vinci designed the first sophisticated robotic arm in 1495 with four degrees-of-freedom and an analog on-board controller supplying power and programmability. von Kemplen's chess-playing automaton left arm was quite sophisticated. Unimate introduced the first industrial robotic arm in 1961, it has subsequently evolved into the PUMA arm. In 1963 the Rancho arm was designed; Minsky's Tentacle arm appeared in 1968, Scheinman's Stanford arm in 1969, and MIT's Silver arm in 1974. Aird became the first cyborg human with a robotic arm in 1993. In 2000 Miguel Nicolalis redefined possible man-machine capacity in his work on cerebral implantation in owl-monkeys directly interfacing with robotic arms both locally and at a distance. The robotic arm is the end-effector of robotic systems and currently is the hallmark feature of the da Vinci Surgical System making its entrance into surgical application. But, despite the potential advantages of this computer-controlled master-slave system, robotic arms have definite limitations. Ongoing work in robotics has many potential solutions to the drawbacks of current robotic surgical systems.

  3. Robots testing robots: ALAN-Arm, a humanoid arm for the testing of robotic rehabilitation systems.

    Science.gov (United States)

    Brookes, Jack; Kuznecovs, Maksims; Kanakis, Menelaos; Grigals, Arturs; Narvidas, Mazvydas; Gallagher, Justin; Levesley, Martin

    2017-07-01

    Robotics is increasing in popularity as a method of providing rich, personalized and cost-effective physiotherapy to individuals with some degree of upper limb paralysis, such as those who have suffered a stroke. These robotic rehabilitation systems are often high powered, and exoskeletal systems can attach to the person in a restrictive manner. Therefore, ensuring the mechanical safety of these devices before they come in contact with individuals is a priority. Additionally, rehabilitation systems may use novel sensor systems to measure current arm position. Used to capture and assess patient movements, these first need to be verified for accuracy by an external system. We present the ALAN-Arm, a humanoid robotic arm designed to be used for both accuracy benchmarking and safety testing of robotic rehabilitation systems. The system can be attached to a rehabilitation device and then replay generated or human movement trajectories, as well as autonomously play rehabilitation games or activities. Tests of the ALAN-Arm indicated it could recreate the path of a generated slow movement path with a maximum error of 14.2mm (mean = 5.8mm) and perform cyclic movements up to 0.6Hz with low gain (<1.5dB). Replaying human data trajectories showed the ability to largely preserve human movement characteristics with slightly higher path length and lower normalised jerk.

  4. The arms race control

    International Nuclear Information System (INIS)

    Nemo, J.

    2010-01-01

    Written in 1961, this paper presents the content of a book entitled 'The arms race control' where the author outlined the difference between disarmament and arms control, described the economic and moral role of arms race, the importance of force balance for international security. He wandered whether arms control could ensure this balance and whether nuclear balance meant force balance. Force balance then appears to be a precarious and unsteady component of international security. He commented the challenges of disarmament, recalled some arguments for a nuclear disarmament. Then he discussed what would be an arms control with or without disarmament (either nuclear or conventional)

  5. Neurobiology: motor control of flexible octopus arms.

    Science.gov (United States)

    Sumbre, Germán; Fiorito, Graziano; Flash, Tamar; Hochner, Binyamin

    2005-02-10

    Animals with rigid skeletons can rely on several mechanisms to simplify motor control--for example, they have skeletal joints that reduce the number of variables and degrees of freedom that need to be controlled. Here we show that when the octopus uses one of its long and highly flexible arms to transfer an object from one place to another, it employs a vertebrate-like strategy, temporarily reconfiguring its arm into a stiffened, articulated, quasi-jointed structure. This indicates that an articulated limb may provide an optimal solution for achieving precise, point-to-point movements.

  6. Training the Unimpaired Arm Improves the Motion of the Impaired Arm and the Sitting Balance in Chronic Stroke Survivors.

    Science.gov (United States)

    De Luca, Alice; Giannoni, Psiche; Vernetti, Honore; Capra, Cristina; Lentino, Carmelo; Checchia, Giovanni Antonio; Casadio, Maura

    2017-07-01

    Robot-assisted rehabilitation of stroke survivors mainly focuses on the impaired side of the body while the role of the unimpaired side in the recovery after stroke is still controversial. The goal of this study is to investigate the influence on sitting balance and paretic arm functions of a training protocol based on movements of the unimpaired arm. Sixteen chronic stroke survivors underwent nineteen training sessions, in which they performed active movements with the unimpaired arm supported by a passive exoskeleton. Performance of the trunk and upper limbs was evaluated before treatment, after treatment and at six months follow up with clinical scales and an instrumented evaluation. A reaching test executed with the exoskeleton was used to assess changes in performance of both arms. The treatment based on the unimpaired arm's movements executed with a correct body posture led to benefits in control of the trunk and of both the trained and the untrained arm. The amount of impaired arm improvement in the Fugl-Meyer score was comparable to the outcome of robotic treatments focused directly on this arm. Our results highlight the importance of taking into account all body schema in the rehabilitation robotic program, instead of focusing only on the impaired side of the body.

  7. Mental representation of arm motion dynamics in children and adolescents.

    Directory of Open Access Journals (Sweden)

    Lionel Crognier

    Full Text Available Motor imagery, i.e., a mental state during which an individual internally represents an action without any overt motor output, is a potential tool to investigate action representation during development. Here, we took advantage of the inertial anisotropy phenomenon to investigate whether children can generate accurate motor predictions for movements with varying dynamics. Children (9 and 11 years, adolescents (14 years and young adults (21 years carried-out actual and mental arm movements in two different directions in the horizontal plane: rightwards (low inertia and leftwards (high inertia. We recorded and compared actual and mental movement times. We found that actual movement times were greater for leftward than rightward arm movements in all groups. For mental movements, differences between leftward versus rightward movements were observed in the adults and adolescents, but not among the children. Furthermore, significant differences between actual and mental times were found at 9 and 11 years of age in the leftward direction. The ratio R/L (rightward direction/leftward direction, which indicates temporal differences between low inertia and high inertia movements, was inferior to 1 at all ages, except for the mental movements at 9 years of age, indicating than actual and mental movements were shorter for the rightward than leftward direction. Interestingly, while the ratio R/L of actual movements was constant across ages, it gradually decreased with age for mental movements. The ratio A/M (actual movement/mental movement, which indicates temporal differences between actual and mental movements, was near to 1 in the adults' groups, denoting accurate mental timing. In children and adolescents, an underestimation of mental movement times appeared for the leftward movements only. However, this overestimation gradually decreased with age. Our results showed a refinement in the motor imagery ability during development. Action representation

  8. Arms control and disarmament

    International Nuclear Information System (INIS)

    Acton, P.

    1992-01-01

    Article VI of the Non-Proliferation Treaty commits each party to work towards nuclear disarmament and to negotiations to stop the nuclear arms race. All parties to the Treaty are included and a wide range of arms control and disarmament issues are covered. However the main focus at Treaty review conferences has been on nuclear disarmament by the nuclear weapon states which are party to the Treaty. This has led to bilateral United States - Soviet Union negotiations resulting in the Intermediate-range Nuclear Forces Treaty in December 1987 and the Strategic Arms Reduction Treaty (START) in July followed by unilateral arms control measures in September and October 1991. (UK)

  9. ARM Mentor Selection Process

    Energy Technology Data Exchange (ETDEWEB)

    Sisterson, D. L. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-10-01

    The Atmospheric Radiation Measurement (ARM) Program was created in 1989 with funding from the U.S. Department of Energy (DOE) to develop several highly instrumented ground stations to study cloud formation processes and their influence on radiative transfer. In 2003, the ARM Program became a national scientific user facility, known as the ARM Climate Research Facility. This scientific infrastructure provides for fixed sites, mobile facilities, an aerial facility, and a data archive available for use by scientists worldwide through the ARM Climate Research Facility—a scientific user facility. The ARM Climate Research Facility currently operates more than 300 instrument systems that provide ground-based observations of the atmospheric column. To keep ARM at the forefront of climate observations, the ARM infrastructure depends heavily on instrument scientists and engineers, also known as lead mentors. Lead mentors must have an excellent understanding of in situ and remote-sensing instrumentation theory and operation and have comprehensive knowledge of critical scale-dependent atmospheric processes. They must also possess the technical and analytical skills to develop new data retrievals that provide innovative approaches for creating research-quality data sets. The ARM Climate Research Facility is seeking the best overall qualified candidate who can fulfill lead mentor requirements in a timely manner.

  10. Security and arms control

    International Nuclear Information System (INIS)

    Kolodziej, E.A.; Morgan, P.M.

    1989-01-01

    This book attempts to clarify and define selected current issues and problems related to security and arms control from an international perspective. The chapters are organized under the following headings. Conflict and the international system, Nuclear deterrence, Conventional warfare, Subconventional conflict, Arms control and crisis management

  11. Managing new arms races

    International Nuclear Information System (INIS)

    Segal, G.

    1992-01-01

    The management of new arms races in the region of Asia-Pacific includes considerations of weapons trade and transfer in the region, with an emphasis on nuclear weapons proliferation. It deals with the problem of controlling the arms trade and the efforts to control conventional weapons and underlines the possible role and influence of Conference on Cooperation and Security in Europe (CSCE)

  12. Protest movements

    International Nuclear Information System (INIS)

    Rucht, D.

    1989-01-01

    The author describes the development of protest movements in postwar Germay and outlines two essential overlapping 'flow cycles'. The first of these was characterised by the restaurative postwar years. It culminated and ended in the students' revolt. This revolt is at the same time the start of a second cycle of protest which encompasses all subsequent individual movement and is initated by an economic, political and sociocultural procrastination of modernisation. This cycle culminates in the late 70s and early 80s and clearly lost momentum over the last few years. The follwoing phases and themes are described profoundly: against restauration and armament in the 1950; the revolutionary impatience of the students' movement, politisation of everyday life by the womens' movement and citizens' action groups, antinuclear- and ecological movement, differentiation and stabilisation of the movement in the 70s and 80s; break-up and continuity in the German protest behaviour. The paper contains a detailed chronicle of protest activities since 1945. (orig.) [de

  13. Polycythemia vera presenting with left hemichoreiform movements. A case report

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Tamiharu; Shimomura, Chikako; Ishibashi, Hiroshi; Tsujihata, Mitsuhiro; Nagataki, Shigenobu

    1985-01-01

    A 65-year-old man developed abruptly choreiform movements involving the left face, arm and leg one day prior to admission. Physical examination revealed red face and palms, hyperemic conjunctivae and atrial fibrillations. Blood pressure was 168/90. Spleen was not palpable. Hemichoreiform movements of the left face and limbs were observed. There was no other neurological abnormalities. Laboratory studies showed RBC 880 x 10U, Hb 22.4g/dl, Hct 63%, WBC 8,100, platelets 22.9 x 10U, ESR 0mm/hr, RBC oxygen saturation 97%, serum iron 67 g/dl, LDH 593 units, uric acid 14mg/dl, and erythropoietine (HI method) 19mIU/ml (normal 28-88). Bone marrow showed myeloid nucleated cell count 38.6 x 10U. ECG showed atrial fibrillations. Chest X-ray and scintigrams of liver and spleen were normal. CSF was normal. Brain CT scan on admission disclosed a low density area in right caudate nucleus. The choreiform movements were rapidly mitigated by venesection and by oral administration of haloperidol(3mg daily). There weeks after discontinuing haloperidol, the hemichorea returned. The routine hematology showed RBC 870 x 10U, Hb 19.8g/dl, Hct 62%, WBC 10,200, and plateret 37.4 x 10U. Another venesection reduced the chorea. Pipobroman was administered to control the polycythemia vera. He has been free of choreic movements thereafter. Choreiform movement is rarely observed in polycythemia vera. The pathogenesis is still unknown. The venous congestion, however, may play a role in this case because the choreic movements disappeared by venesection. (author).

  14. Optimal sensorimotor control in eye movement sequences.

    Science.gov (United States)

    Munuera, Jérôme; Morel, Pierre; Duhamel, Jean-René; Deneve, Sophie

    2009-03-11

    Fast and accurate motor behavior requires combining noisy and delayed sensory information with knowledge of self-generated body motion; much evidence indicates that humans do this in a near-optimal manner during arm movements. However, it is unclear whether this principle applies to eye movements. We measured the relative contributions of visual sensory feedback and the motor efference copy (and/or proprioceptive feedback) when humans perform two saccades in rapid succession, the first saccade to a visual target and the second to a memorized target. Unbeknownst to the subject, we introduced an artificial motor error by randomly "jumping" the visual target during the first saccade. The correction of the memory-guided saccade allowed us to measure the relative contributions of visual feedback and efferent copy (and/or proprioceptive feedback) to motor-plan updating. In a control experiment, we extinguished the target during the saccade rather than changing its location to measure the relative contribution of motor noise and target localization error to saccade variability without any visual feedback. The motor noise contribution increased with saccade amplitude, but remained <30% of the total variability. Subjects adjusted the gain of their visual feedback for different saccade amplitudes as a function of its reliability. Even during trials where subjects performed a corrective saccade to compensate for the target-jump, the correction by the visual feedback, while stronger, remained far below 100%. In all conditions, an optimal controller predicted the visual feedback gain well, suggesting that humans combine optimally their efferent copy and sensory feedback when performing eye movements.

  15. Nonspecific Arm Pain

    Directory of Open Access Journals (Sweden)

    Ali Moradi

    2013-12-01

    Full Text Available Nonspecific activity-related arm pain is characterized by an absence of objective physical findings and symptoms that do not correspond with objective pathophysiology. Arm pain without strict diagnosis is often related to activity, work-related activity in particular, and is often seen in patients with physically demanding work. Psychological factors such as catastrophic thinking, symptoms of depression, and heightened illness concern determine a substantial percentage of the disability associated with puzzling hand and arm pains. Ergonomic modifications can help to control symptoms, but optimal health may require collaborative management incorporating psychosocial and psychological elements of illness.

  16. Nonspecific Arm Pain

    Directory of Open Access Journals (Sweden)

    Ali Moradi

    2013-12-01

    Full Text Available   Nonspecific activity-related arm pain is characterized by an absence of objective physical findings and symptoms that do not correspond with objective pathophysiology. Arm pain without strict diagnosis is often related to activity, work-related activity in particular, and is often seen in patients with physically demanding work. Psychological factors such as catastrophic thinking, symptoms of depression, and heightened illness concern determine a substantial percentage of the disability associated with puzzling hand and arm pains. Ergonomic modifications can help to control symptoms, but optimal health may require collaborative management incorporating psychosocial and psychological elements of illness.

  17. Practical application with plc in manipulation of a robotic arm

    Directory of Open Access Journals (Sweden)

    Cristian Barz

    2014-12-01

    Full Text Available This paper presents the use of a robotic arm PLC Siemens in order not using CNC commands. This is done by programming the PLC ladder diagram language that makes movement on the three axes of the arm by means of stepper motors. Required command console PLC is built with the help of a touch screen HMI Weintek. In the user interface are introduced distances and displacement speeds on the three axes.

  18. Stereotypic Movements in Case of Sporadic Creutzfeldt-Jakob Disease: Possible Role of Anti-NMDA Receptor Antibodies

    Directory of Open Access Journals (Sweden)

    Michelle Molina

    2012-12-01

    Full Text Available Sporadic Creutzfeldt-Jakob disease (sCJD and anti-NMDA receptor antibody encephalitis (NMDAE can both produce a rapidly progressive dementia with resulting state of catatonia or akinetic mutism. Both are associated with movement disorders. In published case series, myoclonus appears to be the most frequent movement disorder in sCJD, while stereotypic, synchronized, one-cycle-per-second movements such as arm or leg elevation, jaw opening, grimacing, head turning, and eye deviation are seen in NMDAE. We report a case of a 59-year-old woman with rapidly worsening cognitive disturbance leading to a nearly catatonic state interrupted by stereotypic movements. sCJD was diagnosed via periodic sharp wave complexes on EEG as well as cerebrospinal fluid (CSF 14-3-3 and tau protein elevation. Characteristic movement disorder of NMDAE was present in absence of ovarian mass or CSF pleiocytosis. Given prior case reports of presence of anti-NMDA receptor antibodies in sCJD, we propose that the movement disorder in this case was caused by anti-NMDA receptor antibodies whose formation was secondary to neuronal damage from prion disease. It is important to consider sCJD even in cases that have some clinical features suggestive of NMDAE.

  19. Arms Trafficking and Colombia

    National Research Council Canada - National Science Library

    Cragin, Kim; Hoffman, Bruce

    2003-01-01

    ... to traditional definitions of a security threat. For this analysis, the term "small arms" refers to man-portable personal and military weapons, ranging from handguns to assault rifles to surface-to-air missiles (SAMs...

  20. Arms Races and Negotiations

    OpenAIRE

    Sandeep Baliga; Tomas Sjostrom

    2003-01-01

    Two players simultaneously decide whether or not to acquire new weapons in an arms race game. Each player's type determines his propensity to arm. Types are private information, and are independently drawn from a continuous distribution. With probability close to one, the best outcome for each player is for neither to acquire new weapons (although each prefers to acquire new weapons if he thinks the opponent will). There is a small probability that a player is a dominant strategy type who alw...

  1. Spatial memory and animal movement.

    Science.gov (United States)

    Fagan, William F; Lewis, Mark A; Auger-Méthé, Marie; Avgar, Tal; Benhamou, Simon; Breed, Greg; LaDage, Lara; Schlägel, Ulrike E; Tang, Wen-wu; Papastamatiou, Yannis P; Forester, James; Mueller, Thomas

    2013-10-01

    Memory is critical to understanding animal movement but has proven challenging to study. Advances in animal tracking technology, theoretical movement models and cognitive sciences have facilitated research in each of these fields, but also created a need for synthetic examination of the linkages between memory and animal movement. Here, we draw together research from several disciplines to understand the relationship between animal memory and movement processes. First, we frame the problem in terms of the characteristics, costs and benefits of memory as outlined in psychology and neuroscience. Next, we provide an overview of the theories and conceptual frameworks that have emerged from behavioural ecology and animal cognition. Third, we turn to movement ecology and summarise recent, rapid developments in the types and quantities of available movement data, and in the statistical measures applicable to such data. Fourth, we discuss the advantages and interrelationships of diverse modelling approaches that have been used to explore the memory-movement interface. Finally, we outline key research challenges for the memory and movement communities, focusing on data needs and mathematical and computational challenges. We conclude with a roadmap for future work in this area, outlining axes along which focused research should yield rapid progress. © 2013 John Wiley & Sons Ltd/CNRS.

  2. Striking movements

    DEFF Research Database (Denmark)

    Dahl, Sofia

    2011-01-01

    Like all music performance, percussion playing requires high control over timing and sound properties. Specific to percussionists, however, is the need to adjust the movement to different instruments with varying physical properties and tactile feedback to the player. Furthermore, the well defined...... note onsets and short interaction times between player and instrument do not allow for much adjustment once a stroke is initiated. The paper surveys research that shows a close relationship between movement and sound production, and how playing conditions such as tempo and the rebound after impact...

  3. Hello to Arms

    Science.gov (United States)

    2005-01-01

    This image highlights the hidden spiral arms (blue) that were discovered around the nearby galaxy NGC 4625 by the ultraviolet eyes of NASA's Galaxy Evolution Explorer. The image is composed of ultraviolet and visible-light data, from the Galaxy Evolution Explorer and the California Institute of Technology's Digitized Sky Survey, respectively. Near-ultraviolet light is colored green; far-ultraviolet light is colored blue; and optical light is colored red. As the image demonstrates, the lengthy spiral arms are nearly invisible when viewed in optical light while bright in ultraviolet. This is because they are bustling with hot, newborn stars that radiate primarily ultraviolet light. The youthful arms are also very long, stretching out to a distance four times the size of the galaxy's core. They are part of the largest ultraviolet galactic disk discovered so far. Located 31 million light-years away in the constellation Canes Venatici, NGC 4625 is the closest galaxy ever seen with such a young halo of arms. It is slightly smaller than our Milky Way, both in size and mass. However, the fact that this galaxy's disk is forming stars very actively suggests that it might evolve into a more massive and mature galaxy resembling our own. The armless companion galaxy seen below NGC 4625 is called NGC 4618. Astronomers do not know why it lacks arms but speculate that it may have triggered the development of arms in NGC 4625.

  4. Tracked Robot with Blade Arms to Enhance Crawling Capability

    OpenAIRE

    Jhu-Wei Ji; Fa-Shian Chang; Lih-Tyng Hwang; Chih-Feng Liu; Jeng-Nan Lee; Shun-Min Wang; Kai-Yi Cho

    2016-01-01

    This paper presents a tracked robot with blade arms powered to assist movement in difficult environments. As a result, the tracked robot is able to pass a ramp or climb stairs. The main feature is a pair of blade arms on both sides of the vehicle body working in collaboration with previously validated transformable track system. When the robot encounters an obstacle in a terrain, it enlists the blade arms with power to overcome the obstacle. In disaster areas, there usually will be terrains t...

  5. Rapid response systems.

    Science.gov (United States)

    Lyons, Patrick G; Edelson, Dana P; Churpek, Matthew M

    2018-07-01

    Rapid response systems are commonly employed by hospitals to identify and respond to deteriorating patients outside of the intensive care unit. Controversy exists about the benefits of rapid response systems. We aimed to review the current state of the rapid response literature, including evolving aspects of afferent (risk detection) and efferent (intervention) arms, outcome measurement, process improvement, and implementation. Articles written in English and published in PubMed. Rapid response systems are heterogeneous, with important differences among afferent and efferent arms. Clinically meaningful outcomes may include unexpected mortality, in-hospital cardiac arrest, length of stay, cost, and processes of care at end of life. Both positive and negative interventional studies have been published, although the two largest randomized trials involving rapid response systems - the Medical Early Response and Intervention Trial (MERIT) and the Effect of a Pediatric Early Warning System on All-Cause Mortality in Hospitalized Pediatric Patients (EPOCH) trial - did not find a mortality benefit with these systems, albeit with important limitations. Advances in monitoring technologies, risk assessment strategies, and behavioral ergonomics may offer opportunities for improvement. Rapid responses may improve some meaningful outcomes, although these findings remain controversial. These systems may also improve care for patients at the end of life. Rapid response systems are expected to continue evolving with novel developments in monitoring technologies, risk prediction informatics, and work in human factors. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Physiologically Relevant Prosthetic Limb Movement Feedback for Upper and Lower Extremity Amputees

    Science.gov (United States)

    2016-10-01

    upper arm (elbow movement), Upper leg (knee movement) and lower leg ( ankle movement) to provide a physiologically relevant sense of limb movement...Additionally a BOA cable tensioning system is passed through these plates and anchored to the external surface of the socket. When tension is applied the

  7. Movement disorders

    International Nuclear Information System (INIS)

    Leenders, K.L.

    1986-01-01

    This thesis describes the measurement of brain-tissue functions in patients with movement disorders using positron emission tomography (PET). This scanning technique is a method for direct in vivo quantitation of the regional tissue content of positron emitting radionuclides in brain (or other organs) in an essentially non-invasive way. Ch. 2 outlines some general features of PET and describes the scanner which has been used for the studies in this thesis. Also the tracer methodology, as applied to data investigations of movement disorders, are discussed. Ch. 3 contains the results of the PET investigations which were performed in the study of movement disorders. The results are presented in the form of 12 papers. The main goals of these studies were the understanding of the pathophysiology of Parkinson's disease, Huntington's chorea, Steele-Richardson-Olzewski syndrome and special case reports. Ch. 4 summarizes the results of these publications and Ch. 5 concludes the main part of this thesis with a general discussion of movement disorders in relation to PET investigations. 697 refs.; 60 figs.; 31 tabs

  8. Psychodynamic Movement

    DEFF Research Database (Denmark)

    Pedersen, Inge Nygaard

    2002-01-01

    This chapter/article describes the historical development of the disciplin Psychodynamic Movement. The importance of this disciplin for self-experience and for training in developing a therapist identy for the music therapy students are emphasized. Prototypeexercises developed and simplified...

  9. Mixed Movements

    DEFF Research Database (Denmark)

    Brabrand, Helle

    2010-01-01

    levels than those related to building, and this exploration is a special challenge and competence implicit artistic development work. The project Mixed Movements generates drawing-material, not primary as representation, but as a performance-based media, making the body being-in-the-media felt and appear...... as possible operational moves....

  10. Vestibular feedback maintains reaching accuracy during body movement

    Science.gov (United States)

    Reynolds, Raymond F.

    2016-01-01

    Key points Reaching movements can be perturbed by vestibular input, but the function of this response is unclear.Here, we applied galvanic vestibular stimulation concurrently with real body movement while subjects maintained arm position either fixed in space or fixed with respect to their body.During the fixed‐in‐space conditions, galvanic vestibular stimulation caused large changes in arm trajectory consistent with a compensatory response to maintain upper‐limb accuracy in the face of body movement.Galvanic vestibular stimulation responses were absent during the body‐fixed task, demonstrating task dependency in vestibular control of the upper limb.The results suggest that the function of vestibular‐evoked arm movements is to maintain the accuracy of the upper limb during unpredictable body movement, but only when reaching in an earth‐fixed reference frame. Abstract When using our arms to interact with the world, unintended body motion can introduce movement error. A mechanism that could detect and compensate for such motion would be beneficial. Observations of arm movements evoked by vestibular stimulation provide some support for this mechanism. However, the physiological function underlying these artificially evoked movements is unclear from previous research. For such a mechanism to be functional, it should operate only when the arm is being controlled in an earth‐fixed rather than a body‐fixed reference frame. In the latter case, compensation would be unnecessary and even deleterious. To test this hypothesis, subjects were gently rotated in a chair while being asked to maintain their outstretched arm pointing towards either earth‐fixed or body‐fixed memorized targets. Galvanic vestibular stimulation was applied concurrently during rotation to isolate the influence of vestibular input, uncontaminated by inertial factors. During the earth‐fixed task, galvanic vestibular stimulation produced large polarity‐dependent corrections in arm

  11. Armed conflict and child health.

    Science.gov (United States)

    Rieder, Michael; Choonara, Imti

    2012-01-01

    Armed conflict has a major impact on child health throughout the world. One in six children worldwide lives in an area of armed conflict and civilians are more likely to die than soldiers as a result of the conflict. In stark contrast to the effect on children, the international arms trade results in huge profits for the large corporations involved in producing arms, weapons and munitions. Armed conflict is not inevitable but is an important health issue that should be prevented.

  12. Arm to leg coordination in elite butterfly swimmers.

    Science.gov (United States)

    Chollet, D; Seifert, L; Boulesteix, L; Carter, M

    2006-04-01

    This study proposed the use of four time gaps to assess arm-to-leg coordination in the butterfly stroke at increasing race paces. Fourteen elite male swimmers swam at four velocities corresponding to the appropriate paces for, respectively, the 400-m, 200-m, 100-m, and 50-m events. The different stroke phases of the arm and leg were identified by video analysis and then used to calculate four time gaps (T1: time gap between entry of the hands in the water and the high break-even point of the first undulation; T2: time gap between the beginning of the hands' backward movement and the low break-even point of the first undulation; T3: time gap between the hands' arrival in a vertical plane to the shoulders and the high break-even point of the second undulation; T4: time gap between the hands' release from the water and the low break-even point of the second undulation), the values of which described the changing relationship of arm to leg movements over an entire stroke cycle. With increases in pace, elite swimmers increased the stroke rate, the relative duration of the arm pull, the recovery and the first downward movement of the legs, and decreased the stroke length, the relative duration of the arm catch phase and the body glide with arms forward (measured by T2), until continuity in the propulsive actions was achieved. Whatever the paces, the T1, T3, and T4 values were close to zero and revealed a high degree of synchronisation at key motor points of the arm and leg actions. This new method to assess butterfly coordination could facilitate learning and coaching by situating the place of the leg undulation in relation with the arm stroke.

  13. Constraint-induced movement therapy after stroke

    NARCIS (Netherlands)

    Kwakkel, G.; Veerbeek, J.M.; van Wegen, E.E.H.; Wolf, S.L.

    2015-01-01

    Constraint-induced movement therapy (CIMT) was developed to overcome upper limb impairments after stroke and is the most investigated intervention for the rehabilitation of patients. Original CIMT includes constraining of the non-paretic arm and task-oriented training. Modified versions also apply

  14. Computational movement analysis

    CERN Document Server

    Laube, Patrick

    2014-01-01

    This SpringerBrief discusses the characteristics of spatiotemporal movement data, including uncertainty and scale. It investigates three core aspects of Computational Movement Analysis: Conceptual modeling of movement and movement spaces, spatiotemporal analysis methods aiming at a better understanding of movement processes (with a focus on data mining for movement patterns), and using decentralized spatial computing methods in movement analysis. The author presents Computational Movement Analysis as an interdisciplinary umbrella for analyzing movement processes with methods from a range of fi

  15. Worldwide Report, Arms Control

    Science.gov (United States)

    1986-02-28

    NACHRICHTEN , 18 Oct 85) 39 Presummit Polish Reporting on SDI Issues (Warsaw RZECZPOSPOLITA, 19-20 Oct 85; Warsaw ZYCIE WARSZAWY, 15 Oct 85) 42...28 February 1986 SDI AND SPACE ARMS MEETING REVEALS SOME SUPPORT FOR EUREKA LINK TO MILITARY Puesseldbrf VDI NACHRICHTEN in German 18 Oct 85 p 10

  16. Worldwide Report, Arms Control.

    Science.gov (United States)

    1986-02-04

    8217Unpredictable Consequences’ of SDI (Moscow PRAVDA, 7 Dec 85) 22 Moscow TV on ASTEC Meeting, Military Monopolies, SDI (Tomas Kolesnichenko; Moscow...planet. /8309 CSO: 5200/1228 22 JPRS-TAO86*014 4 February 1986 SDI AND SPACE ARMS MOSCOW TV ON ASTEC MEETING, MILITARY MONOPOLIES, SDI

  17. Affine pairings on ARM

    NARCIS (Netherlands)

    Acar, T.; Lauter, K.; Naehrig, M.; Shumow, D.; Abdalla, M.; Lange, T.

    2013-01-01

    We report on relative performance numbers for affine and projective pairings on a dual-core Cortex A9 ARM processor. Using a fast inversion in the base field and doing inversion in extension fields by using the norm map to reduce to inversions in smaller fields, we find a very low ratio of

  18. Arms Trafficking and Colombia

    Science.gov (United States)

    2003-01-01

    chronology of the intensification of violence in the area, see Noche Y Niebla: Panorama De Derechos Humanos Y Violencia Politica En Colombia, Bogotá...Arms, London, UK: Zed Books, 2000, pp. 155–178. Noche Y Niebla: Panorama De Derechos Humanos Y Violencia Politica En Colombia, Bogotá: Cinep & Justicia

  19. Rapid Eye Movement Sleep, Sleep Continuity and Slow Wave Sleep as Predictors of Cognition, Mood, and Subjective Sleep Quality in Healthy Men and Women, Aged 20–84 Years

    Directory of Open Access Journals (Sweden)

    Ciro della Monica

    2018-06-01

    Full Text Available Sleep and its sub-states are assumed to be important for brain function across the lifespan but which aspects of sleep associate with various aspects of cognition, mood and self-reported sleep quality has not yet been established in detail. Sleep was quantified by polysomnography, quantitative Electroencephalogram (EEG analysis and self-report in 206 healthy men and women, aged 20–84 years, without sleep complaints. Waking brain function was quantified by five assessments scheduled across the day covering objectively assessed performance across cognitive domains including sustained attention and arousal, decision and response time, motor and sequence control, working memory, and executive function as well as self-reports of alertness, mood and affect. Controlled for age and sex, self-reported sleep quality was negatively associated with number of awakenings and positively associated with the duration of Rapid Eye Movement (REM sleep, but no significant associations with Slow Wave Sleep (SWS measures were observed. Controlling only for age showed that associations between objective and subjective sleep quality were much stronger in women than in men. Analysis of 51 performance measures demonstrated that, after controlling for age and sex, fewer awakenings and more REM sleep were associated significantly with better performance on the Goal Neglect task, which is a test of executive function. Factor analysis of the individual performance measures identified four latent variables labeled Mood/Arousal, Response Time, Accuracy, and Visual Perceptual Sensitivity. Whereas Mood/Arousal improved with age, Response Times became slower, while Accuracy and Visual perceptual sensitivity showed little change with age. After controlling for sex and age, nominally significant association between sleep and factor scores were observed such that Response Times were faster with more SWS, and Accuracy was reduced where individuals woke more often or had less REM

  20. Neural processes mediating the preparation and release of focal motor output are suppressed or absent during imagined movement

    Science.gov (United States)

    Eagles, Jeremy S.; Carlsen, Anthony N.

    2016-01-01

    Movements that are executed or imagined activate a similar subset of cortical regions, but the extent to which this activity represents functionally equivalent neural processes is unclear. During preparation for an executed movement, presentation of a startling acoustic stimulus (SAS) evokes a premature release of the planned movement with the spatial and temporal features of the tasks essentially intact. If imagined movement incorporates the same preparatory processes as executed movement, then a SAS should release the planned movement during preparation. This hypothesis was tested using an instructed-delay cueing paradigm during which subjects were required to rapidly release a handheld weight while maintaining the posture of the arm or to perform first-person imagery of the same task while holding the weight. In a subset of trials, a SAS was presented at 1500, 500, or 200 ms prior to the release cue. Task-appropriate preparation during executed and imagined movements was confirmed by electroencephalographic recording of a contingent negative variation waveform. During preparation for executed movement, a SAS often resulted in premature release of the weight with the probability of release progressively increasing from 24 % at −1500 ms to 80 % at −200 ms. In contrast, the SAS rarely (movement. However, the SAS frequently evoked the planned postural response (suppression of bicep brachii muscle activity) irrespective of the task or timing of stimulation (even during periods of postural hold without preparation). These findings provide evidence that neural processes mediating the preparation and release of the focal motor task (release of the weight) are markedly attenuated or absent during imagined movement and that postural and focal components of the task are prepared independently. PMID:25744055

  1. The Coding and Effector Transfer of Movement Sequences

    Science.gov (United States)

    Kovacs, Attila J.; Muhlbauer, Thomas; Shea, Charles H.

    2009-01-01

    Three experiments utilizing a 14-element arm movement sequence were designed to determine if reinstating the visual-spatial coordinates, which require movements to the same spatial locations utilized during acquisition, results in better effector transfer than reinstating the motor coordinates, which require the same pattern of homologous muscle…

  2. Temporal alignment of electrocorticographic recordings for upper limb movement.

    Science.gov (United States)

    Talakoub, Omid; Popovic, Milos R; Navaro, Jessie; Hamani, Clement; Fonoff, Erich T; Wong, Willy

    2014-01-01

    The detection of movement-related components of the brain activity is useful in the design of brain-machine interfaces. A common approach is to classify the brain activity into a number of templates or states. To find these templates, the neural responses are averaged over each movement task. For averaging to be effective, one must assume that the neural components occur at identical times over repeated trials. However, complex arm movements such as reaching and grasping are prone to cross-trial variability due to the way movements are performed. Typically initiation time, duration of movement and movement speed are variable even as a subject tries to reproduce the same task identically across trials. Therefore, movement-related neural activity will tend to occur at different times across the trials. Due to this mismatch, the averaging of neural activity will not bring into salience movement-related components. To address this problem, we present a method of alignment that accounts for the variabilities in the way the movements are conducted. In this study, arm speed was used to align neural activity. Four subjects had electrocorticographic (ECoG) electrodes implanted over their primary motor cortex and were asked to perform reaching and retrieving tasks using the upper limb contralateral to the site of electrode implantation. The arm speeds were aligned using a non-linear transformation of the temporal axes resulting in average spectrograms with superior visualization of movement-related neural activity when compared to averaging without alignment.

  3. Temporal alignment of electrocorticographic recordings for upper limb movement

    Directory of Open Access Journals (Sweden)

    Omid eTalakoub

    2015-01-01

    Full Text Available The detection of movement-related components of the brain activity is useful in the design of brain machine interfaces. A common approach is to classify the brain activity into a number of templates or states. To find these templates, the neural responses are averaged over each movement task. For averaging to be effective, one must assume that the neural components occur at identical times over repeated trials. However, complex arm movements such as reaching and grasping are prone to cross-trial variability due to the way movements are performed. Typically initiation time, duration of movement and movement speed are variable even as a subject tries to reproduce the same task identically across trials. Therefore, movement-related neural activity will tend to occur at different times across each trial. Due to this mismatch, the averaging of neural activity will not bring into salience movement-related components. To address this problem, we present a method of alignment that accounts for the variabilities in the way the movements are conducted. In this study, arm speed was used to align neural activity. Four subjects had electrocorticographic (ECoG electrodes implanted over their primary motor cortex and were asked to perform reaching and retrieving tasks using the upper limb contralateral to the site of electrode implantation. The arm speeds were aligned using a nonlinear transformation of the temporal axes resulting in averaged spectrograms with superior visualization of movement-related neural activity when compared to averaging without alignment.

  4. INDUSTRIAL ROBOT ARM SIMULATION SOFTWARE DEVELOPMENT USING JAVA-3D AND MATLAB SIMULINK PROGRAMMING LANGUAGE

    OpenAIRE

    Wirabhuana, Arya

    2011-01-01

    Robot Arms Simulation Software development using Structured Programming Languages, Third Party Language, and Artificial Intelligence Programming Language are the common techniques in simulating robot arms movement. Those three techniques are having its strengths and weaknesses depend on several constraints such as robot type, degree of operation complexity to be simulated, operator skills, and also computer capability. This paper will discuss on Robot Arms Simulation Software (RSS) developmen...

  5. Swivel arm perimeter for visual field testing in different body positions.

    Science.gov (United States)

    Flammer, J; Hendrickson, P; Lietz, A; Stümpfig, D

    1993-01-01

    To investigate the influence of body position on visual field results, a 'swivel arm perimeter' was built, based on a modified Octopus 1-2-3. Here, the measuring unit was detected from the control unit and mounted on a swivel arm, allowing its movement in all directions. The first results obtained with this device have indicated that its development was worthwhile.

  6. Preliminary results of training with gravity compensation of the arm in chronic stroke survivors

    NARCIS (Netherlands)

    van der Kooij, Herman; Prange, Grada Berendina; Prange, G.B.; Krabben, T.; Krabben, T.; Renzenbrink, G.H.; Boer, J.; Hermens, Hermanus J.; Jannink, M.J.A.

    2009-01-01

    After stroke, arm function can be limited by a reduction in the selectivity of movements, due to involuntary coupling of shoulder abduction and elbow flexion, limiting the ability to reach. Gravity compensation of the arm reduces the required active shoulder abduction torques, which results in a

  7. A software radio platform based on ARM and FPGA

    Directory of Open Access Journals (Sweden)

    Yang Xin.

    2016-01-01

    Full Text Available The rapid rise in computational performance offered by computer systems has greatly increased the number of practical software radio applications. A scheme presented in this paper is a software radio platform based on ARM and FPGA. FPGA works as the coprocessor together with the ARM, which serves as the core processor. ARM is used for digital signal processing and real-time data transmission, and FPGA is used for synchronous timing control and serial-parallel conversion. A SPI driver for real-time data transmission between ARM and FPGA under ARM-Linux system is provided. By adopting modular design, the software radio platform is capable of implementing wireless communication functions and satisfies the requirements of real-time signal processing platform for high security and broad applicability.

  8. Modernization of African Armed Forces

    DEFF Research Database (Denmark)

    Mandrup, Thomas

    2015-01-01

    Concept paper framing the debate at the Dakar Forum Workshop on Modernization of Armed forces in Africa.......Concept paper framing the debate at the Dakar Forum Workshop on Modernization of Armed forces in Africa....

  9. Understanding the conventional arms trade

    Science.gov (United States)

    Stohl, Rachel

    2017-11-01

    The global conventional arms trade is worth tens of billions of dollars every year and is engaged in by every country in the world. Yet, it is often difficult to control the legal trade in conventional arms and there is a thriving illicit market, willing to arm unscrupulous regimes and nefarious non-state actors. This chapter examines the international conventional arms trade, the range of tools that have been used to control it, and challenges to these international regimes.

  10. Safeguarding arms control

    International Nuclear Information System (INIS)

    Flanagan, S.J.

    1988-01-01

    This essay reviews the evolution of various safeguards concepts associated with U.S. Soviet arms control negotiations over the past twenty-five years. It explore in some detail the origins, nature, and effectiveness of the safeguards packages associated with six agreements: the Limited Test Ban Treaty (1963), the SALT I Interim Agreement (1972), the Anti-Ballistic Missile (ABM) Treaty (1972), the Threshold Test Ban Treaty (1974), the Peaceful Nuclear Explosions Treaty (1976) and the SALT II Treaty (1979). Finally, the implications of this historical record for developing future nuclear and conventional arms control accords and for shoring up existing pacts, such as the ABM Treaty, are assessed with a view towards practicable prescriptions for Western policymakers. The treaty eliminating intermediate-range nuclear forces (INF) incorporates several verification safeguards, and it is very likely that analogous measures would be attached to any accord constraining conventional forces in Europe

  11. Coat of Arms.

    Science.gov (United States)

    Smith, Bryan

    1998-01-01

    Describes an activity, the "coat of arms," that can serve as an ice-breaker or warm-up for the first day of an English-as-a-Second/Foreign-Language class, as a motivating start to the week, or act as an innovative segue between skill lessons. The technique can be adapted for students ranging from elementary school to adult language learners of all…

  12. Arms Production in Venezuela.

    Science.gov (United States)

    1987-12-01

    studied engineering in the United States. Cardoen produces a wide spectrum of munitions, security equipment and especially armored vehicles, and has...capabilities are: a. The amount of capital available for investment. Arms industry development requires enormous amounts of capital, especially if the...Naval Postgraduate School Monterey, CA 93943-5100 5. Director de Educacion de La Armada 1 Comandancia General de La Armada Av. Vollmer, Urb. San

  13. Scientific coats of arms.

    Science.gov (United States)

    Fara, Patricia

    2005-09-01

    With their mythical creatures and arcane symbolism, coats of arms seem to have little connection with modern science. Yet despite its chivalric origins, the ancient language of heraldry has long fascinated famous scientists. Although this idiosyncratic tradition was parodied by Victorian geologists, who laughingly replaced unicorns and griffins with images of dinosaurs that they had recently discovered, it has been perpetuated since by Ernest Rutherford, who liked to present himself as a new alchemist.

  14. Liposuction of arm lymphoedema.

    OpenAIRE

    Brorson, Håkan

    2003-01-01

    Breast cancer is the most common disease in women, and up to 38% develop lymphedema of the arm following mastectomy, standard axillary node dissection and postoperative irradiation. Limb reductions have been reported utilising various conservative therapies such as manual lymph and pressure therapy. Some patients with long-standing pronounced lymphedema do not respond to these conservative treatments because slow or absent lymph flow causes the formation of excess subcutaneous adipose tissue....

  15. Kiikuv maja / Anu Arm

    Index Scriptorium Estoniae

    Arm, Anu

    2006-01-01

    Eesti Kunstiakadeemia esimese kursuse arhitektuuriüliõpilaste II semestri töö. Juhendaja arhitekt Andres Alver, ehitamise Pedaspeale organiseeris suvepraktika juhendaja arhitekt Jaan Tiidemann. Autor Anu Arm, kaasa töötasid ja valmis ehitasid: Ott Alver, Maarja Elm, Mari Hunt, Alvin Järving, Marten Kaevats, Riho Kerge, Reedik Poopuu, Anu Põime, Helen Rebane, Kaisa Saarva, Martin Tago, Reet Volt. Valmis: 19. VIII 2006

  16. Strategic arms limitation

    Science.gov (United States)

    Allen Greb, G.; Johnson, Gerald W.

    1983-10-01

    Following World War II, American scientists and politicians proposed in the Baruch plan a radical solution to the problem of nuclear weapons: to eliminate them forever under the auspices of an international nuclear development authority. The Soviets, who as yet did not possess the bomb, rejected this plan. Another approach suggested by Secretary of War Henry Stimson to negotiate directly with the Soviet Union was not accepted by the American leadership. These initial arms limitation failures both reflected and exacerbated the hostile political relationship of the superpowers in the 1950s and 1960s. Since 1969, the more modest focus of the Soviet-American arms control process has been on limiting the numbers and sizes of both defensive and offensive strategic systems. The format for this effort has been the Strategic Arms Limitatins Talks (Salt) and more recently the Strategic Arms Reduction Talks (START). Both sides came to these negotiations convinced that nuclear arsenals had grown so large that some for of mutual restraint was needed. Although the SALT/START process has been slow and ponderous, it has produced several concrete the agreements and collateral benefits. The 1972 ABM Treaty restricts the deployment of ballistic missile defense systems, the 1972 Interim Agreement places a quantitative freeze on each side's land based and sea based strategic launchers, and the as yet unratified 1979 SALT II Treaty sets numerical limits on all offensive strategic systems and sublimits on MIRVed systems. Collateral benefits include improved verification procedures, working definitions and counting rules, and permanent bureaucratic apparatus which enhance stability and increase the chances for achieving additional agreements.

  17. Worldwide Report, Arms Control.

    Science.gov (United States)

    1985-11-22

    dinosaurs (and a large number of other species which disappeared "simultaneously") might have become extinct because a large comet hit the earth’s...clear yet aeain the reasons why Washington is in such haste in the arms race for "star wars" and why it refuses to assume a commitment not to be...Kolesnichenko says: [Begin Kolesnichenko recording in Russian with English translation] In an effort to calm the American public and provide a logical reason

  18. Armed conflict and child health

    OpenAIRE

    Rieder, Michael; Choonara, Imti

    2012-01-01

    Armed conflict has a major impact on child health\\ud throughout the world. One in six children worldwide lives\\ud in an area of armed conflict and civilians are more likely\\ud to die than soldiers as a result of the conflict. In stark\\ud contrast to the effect on children, the international arms\\ud trade results in huge profits for the large corporations\\ud involved in producing arms, weapons and munitions.\\ud Armed conflict is not inevitable but is an important\\ud health issue that should be...

  19. Analyzing octopus movements using three-dimensional reconstruction.

    Science.gov (United States)

    Yekutieli, Yoram; Mitelman, Rea; Hochner, Binyamin; Flash, Tamar

    2007-09-01

    Octopus arms, as well as other muscular hydrostats, are characterized by a very large number of degrees of freedom and a rich motion repertoire. Over the years, several attempts have been made to elucidate the interplay between the biomechanics of these organs and their control systems. Recent developments in electrophysiological recordings from both the arms and brains of behaving octopuses mark significant progress in this direction. The next stage is relating these recordings to the octopus arm movements, which requires an accurate and reliable method of movement description and analysis. Here we describe a semiautomatic computerized system for 3D reconstruction of an octopus arm during motion. It consists of two digital video cameras and a PC computer running custom-made software. The system overcomes the difficulty of extracting the motion of smooth, nonrigid objects in poor viewing conditions. Some of the trouble is explained by the problem of light refraction in recording underwater motion. Here we use both experiments and simulations to analyze the refraction problem and show that accurate reconstruction is possible. We have used this system successfully to reconstruct different types of octopus arm movements, such as reaching and bend initiation movements. Our system is noninvasive and does not require attaching any artificial markers to the octopus arm. It may therefore be of more general use in reconstructing other nonrigid, elongated objects in motion.

  20. Effect of Tendon Vibration on Hemiparetic Arm Stability in Unstable Workspaces.

    Directory of Open Access Journals (Sweden)

    Megan O Conrad

    Full Text Available Sensory stimulation of wrist musculature can enhance stability in the proximal arm and may be a useful therapy aimed at improving arm control post-stroke. Specifically, our prior research indicates tendon vibration can enhance stability during point-to-point arm movements and in tracking tasks. The goal of the present study was to investigate the influence of forearm tendon vibration on endpoint stability, measured at the hand, immediately following forward arm movements in an unstable environment. Both proximal and distal workspaces were tested. Ten hemiparetic stroke subjects and 5 healthy controls made forward arm movements while grasping the handle of a two-joint robotic arm. At the end of each movement, the robot applied destabilizing forces. During some trials, 70 Hz vibration was applied to the forearm flexor muscle tendons. 70 Hz was used as the stimulus frequency as it lies within the range of optimal frequencies that activate the muscle spindles at the highest response rate. Endpoint position, velocity, muscle activity and grip force data were compared before, during and after vibration. Stability at the endpoint was quantified as the magnitude of oscillation about the target position, calculated from the power of the tangential velocity data. Prior to vibration, subjects produced unstable, oscillating hand movements about the target location due to the applied force field. Stability increased during vibration, as evidenced by decreased oscillation in hand tangential velocity.

  1. Individual Movement Variability Magnitudes Are Explained by Cortical Neural Variability.

    Science.gov (United States)

    Haar, Shlomi; Donchin, Opher; Dinstein, Ilan

    2017-09-13

    Humans exhibit considerable motor variability even across trivial reaching movements. This variability can be separated into specific kinematic components such as extent and direction that are thought to be governed by distinct neural processes. Here, we report that individual subjects (males and females) exhibit different magnitudes of kinematic variability, which are consistent (within individual) across movements to different targets and regardless of which arm (right or left) was used to perform the movements. Simultaneous fMRI recordings revealed that the same subjects also exhibited different magnitudes of fMRI variability across movements in a variety of motor system areas. These fMRI variability magnitudes were also consistent across movements to different targets when performed with either arm. Cortical fMRI variability in the posterior-parietal cortex of individual subjects explained their movement-extent variability. This relationship was apparent only in posterior-parietal cortex and not in other motor system areas, thereby suggesting that individuals with more variable movement preparation exhibit larger kinematic variability. We therefore propose that neural and kinematic variability are reliable and interrelated individual characteristics that may predispose individual subjects to exhibit distinct motor capabilities. SIGNIFICANCE STATEMENT Neural activity and movement kinematics are remarkably variable. Although intertrial variability is rarely studied, here, we demonstrate that individual human subjects exhibit distinct magnitudes of neural and kinematic variability that are reproducible across movements to different targets and when performing these movements with either arm. Furthermore, when examining the relationship between cortical variability and movement variability, we find that cortical fMRI variability in parietal cortex of individual subjects explained their movement extent variability. This enabled us to explain why some subjects

  2. Removable molar power arm

    Directory of Open Access Journals (Sweden)

    Raj Kumar Verma

    2013-01-01

    Full Text Available Attachment of force elements from the gingival hook of maxillary molar tubes during the retraction of the anterior teeth is very common in orthodontic practice. As the line of force passes below the center of resistance (CR of molar, it results its mesial tipping and also anchorage loss. To overcome this problem, the line of force should pass along the CR of molar. This article highlights a method to overcome this problem by attaching a removable power arm to the headgear tube of molar tube during the retraction of the anterior teeth.

  3. Disarmament and arms control

    International Nuclear Information System (INIS)

    Elzen, B.

    1979-01-01

    This report discusses how far science and technology can provide methods of making arms control and disarmament agreements more controlable in an objective way. Two case studies have been considered, the test ban treaty and the verification of the number of strategic nuclear weapons. These lead to the conclusion that both science and politics are closely interwoven and that within what appear to be scientific arguments, political positions are being defended. Consequently scientists and technologists and the contexts in which they work, play a prominent role. (C.F.)

  4. EEG Mind Controlled Smart Prosthetic Arm – A Comprehensive Study

    Directory of Open Access Journals (Sweden)

    Taha Beyrouthy

    2017-06-01

    Full Text Available Recently, the field of prosthetics has seen many accomplishments especially with the integration of technological advancements. In this paper, different arm types (robotic, surgical, bionic, prosthetic and static are analyzed in terms of resistance, usage, flexibility, cost and potential. Most of these techniques have some problems; they are extremely expensive, hard to install and maintain and may require surgery. Therefore, our work introduces the initial design of an EEG mind controlled smart prosthetic arm. The arm is controlled by the brain commands, obtained from an electroencephalography (EEG headset, and equipped with a network of smart sensors and actuators that give the patient intelligent feedback about the surrounding environment and the object in contact. This network provides the arm with normal hand functionality, smart reflexes and smooth movements. Various types of sensors are used including temperature, pressure, ultrasonic proximity sensors, accelerometers, potentiometers, strain gauges and gyroscopes. The arm is completely 3D printed built from various lightweight and high strength materials that can handle high impacts and fragile elements as well. Our project requires the use of nine servomotors installed at different places in the arm. Therefore, the static and dynamic modes of servomotors are analyzed. The total cost of the project is estimated to be relatively cheap compared to other previously built arms. Many scenarios are analyzed corresponding to the actions that the prosthetic arm can perform, and an algorithm is created to match these scenarios. Experimental results show that the proposed EEG Mind-controlled Arm is a promising alternative for current solutions that require invasive and expensive surgical procedures.

  5. Recognition and Synthesis of Human Movements by Parametric HMMs

    DEFF Research Database (Denmark)

    Herzog, Dennis; Krüger, Volker

    2009-01-01

    The representation of human movements for recognition and synthesis is important in many application fields such as: surveillance, human-computer interaction, motion capture, and humanoid robots. Hidden Markov models (HMMs) are a common statistical framework in this context, since...... on the recognition and synthesis of human arm movements. Furthermore, we will show in various experiments the use of PHMMs for the control of a humanoid robot by synthesizing movements for relocating objects at arbitrary positions. In vision-based interaction experiments, PHMM are used for the recognition...... of pointing movements, where the recognized parameterization conveys to a robot the important information which object to relocate and where to put it. Finally, we evaluate the accuracy of recognition and synthesis for pointing and grasping arm movements and discuss that the precision of the synthesis...

  6. Positioning the laparoscopic camera with industrial robot arm

    DEFF Research Database (Denmark)

    Capolei, Marie Claire; Wu, Haiyan; Andersen, Nils Axel

    2017-01-01

    This paper introduces a solution for the movement control of the laparoscopic camera employing a teleoperated robotic assistant. The project propose an autonomous robotic solution based on an industrial manipulator, provided with a modular software which is applicable to large scale. The robot arm...... industrial robot arm is designated to accomplish this manipulation task. The software is implemented in ROS in order to facilitate future extensions. The experimental results shows a manipulator capable of moving fast and smoothly the surgical tool around a remote center of motion....

  7. Patterns of motor activity in the isolated nerve cord of the octopus arm.

    Science.gov (United States)

    Gutfreund, Yoram; Matzner, Henry; Flash, Tamar; Hochner, Binyamin

    2006-12-01

    The extremely flexible octopus arm provides a unique opportunity for studying movement control in a highly redundant motor system. We describe a novel preparation that allows analysis of the peripheral nervous system of the octopus arm and its interaction with the muscular and mechanosensory elements of the arm's intrinsic muscular system. First we examined the synaptic responses in muscle fibers to identify the motor pathways from the axial nerve cord of the arm to the surrounding musculature. We show that the motor axons project to the muscles via nerve roots originating laterally from the arm nerve cord. The motor field of each nerve is limited to the region where the nerve enters the arm musculature. The same roots also carry afferent mechanosensory information from the intrinsic muscle to the axial nerve cord. Next, we characterized the pattern of activity generated in the dorsal roots by electrically stimulating the axial nerve cord. The evoked activity, although far reaching and long lasting, cannot alone account for the arm extension movements generated by similar electrical stimulation. The mismatch between patterns of activity in the isolated cord and in an intact arm may stem from the involvement of mechanosensory feedback in natural arm extension.

  8. Ray tracing reconstruction investigation for C-arm tomosynthesis

    Science.gov (United States)

    Malalla, Nuhad A. Y.; Chen, Ying

    2016-04-01

    C-arm tomosynthesis is a three dimensional imaging technique. Both x-ray source and the detector are mounted on a C-arm wheeled structure to provide wide variety of movement around the object. In this paper, C-arm tomosynthesis was introduced to provide three dimensional information over a limited view angle (less than 180o) to reduce radiation exposure and examination time. Reconstruction algorithms based on ray tracing method such as ray tracing back projection (BP), simultaneous algebraic reconstruction technique (SART) and maximum likelihood expectation maximization (MLEM) were developed for C-arm tomosynthesis. C-arm tomosynthesis projection images of simulated spherical object were simulated with a virtual geometric configuration with a total view angle of 40 degrees. This study demonstrated the sharpness of in-plane reconstructed structure and effectiveness of removing out-of-plane blur for each reconstruction algorithms. Results showed the ability of ray tracing based reconstruction algorithms to provide three dimensional information with limited angle C-arm tomosynthesis.

  9. Robotic Mirror Therapy System for Functional Recovery of Hemiplegic Arms.

    Science.gov (United States)

    Beom, Jaewon; Koh, Sukgyu; Nam, Hyung Seok; Kim, Wonshik; Kim, Yoonjae; Seo, Han Gil; Oh, Byung-Mo; Chung, Sun Gun; Kim, Sungwan

    2016-08-15

    Mirror therapy has been performed as effective occupational therapy in a clinical setting for functional recovery of a hemiplegic arm after stroke. It is conducted by eliciting an illusion through use of a mirror as if the hemiplegic arm is moving in real-time while moving the healthy arm. It can facilitate brain neuroplasticity through activation of the sensorimotor cortex. However, conventional mirror therapy has a critical limitation in that the hemiplegic arm is not actually moving. Thus, we developed a real-time 2-axis mirror robot system as a simple add-on module for conventional mirror therapy using a closed feedback mechanism, which enables real-time movement of the hemiplegic arm. We used 3 Attitude and Heading Reference System sensors, 2 brushless DC motors for elbow and wrist joints, and exoskeletal frames. In a feasibility study on 6 healthy subjects, robotic mirror therapy was safe and feasible. We further selected tasks useful for activities of daily living training through feedback from rehabilitation doctors. A chronic stroke patient showed improvement in the Fugl-Meyer assessment scale and elbow flexor spasticity after a 2-week application of the mirror robot system. Robotic mirror therapy may enhance proprioceptive input to the sensory cortex, which is considered to be important in neuroplasticity and functional recovery of hemiplegic arms. The mirror robot system presented herein can be easily developed and utilized effectively to advance occupational therapy.

  10. Biomimetics of human movement: functional or aesthetic?

    International Nuclear Information System (INIS)

    Harris, Christopher M

    2009-01-01

    How should robotic or prosthetic arms be programmed to move? Copying human smooth movements is popular in synthetic systems, but what does this really achieve? We cannot address these biomimetic issues without a deep understanding of why natural movements are so stereotyped. In this article, we distinguish between 'functional' and 'aesthetic' biomimetics. Functional biomimetics requires insight into the problem that nature has solved and recognition that a similar problem exists in the synthetic system. In aesthetic biomimetics, nature is copied for its own sake and no insight is needed. We examine the popular minimum jerk (MJ) model that has often been used to generate smooth human-like point-to-point movements in synthetic arms. The MJ model was originally justified as maximizing 'smoothness'; however, it is also the limiting optimal trajectory for a wide range of cost functions for brief movements, including the minimum variance (MV) model, where smoothness is a by-product of optimizing the speed-accuracy trade-off imposed by proportional noise (PN: signal-dependent noise with the standard deviation proportional to mean). PN is unlikely to be dominant in synthetic systems, and the control objectives of natural movements (speed and accuracy) would not be optimized in synthetic systems by human-like movements. Thus, employing MJ or MV controllers in robotic arms is just aesthetic biomimetics. For prosthetic arms, the goal is aesthetic by definition, but it is still crucial to recognize that MV trajectories and PN are deeply embedded in the human motor system. Thus, PN arises at the neural level, as a recruitment strategy of motor units and probably optimizes motor neuron noise. Human reaching is under continuous adaptive control. For prosthetic devices that do not have this natural architecture, natural plasticity would drive the system towards unnatural movements. We propose that a truly neuromorphic system with parallel force generators (muscle fibres) and noisy

  11. Functional Movement Disorder

    Science.gov (United States)

    ... Publications Patient Organizations International Parkinson and Movement Disorder Society National Institute of Mental Health (NIMH) See all related organizations Publications Order NINDS Publications Definition Psychogenic movement is an unwanted muscle movement such ...

  12. Nature of galaxy spiral arms

    International Nuclear Information System (INIS)

    Efremov, Yu.N.

    1984-01-01

    The nature of galaxy spiral arms is discussed in a popular form. Two approaches in the theory of spiral arms are considered; they are related to the problem of differential galaxy rotation and the spiral structure wave theory. The example of Galaxy M31 is considered to compare the structural peculiarity of its spiral arms with the wave theory predictions. The situation in the central and south-eastern part of arm S4 in Galaxy M31 noted to be completely explained by the wave theory and modern concepts on the origin of massive stars

  13. Nuclear arms cleanup

    International Nuclear Information System (INIS)

    Cooper, M.H.

    1994-01-01

    The Soviet Union's demise five years ago brought an end to the Cold War, the 45-year arms race between the Soviet superpower and the United States. The euphoria that greeted the end of this bloodless conflict has dampened somewhat, however, as U.S. officials and their counterparts in the former Soviet republics come to grips with its legacy: thousands of highly toxic and politically destabilizing nuclear weapons. With no more perceived need for much of their vast arsenals, the governments have agreed to dismantle large numbers of nuclear warheads. But the agencies involved in this task face a daunting technical and political problem: what to do with the thousands of tons of plutonium and uranium that are the main ingredients of nuclear weapons

  14. The Neanderthal lower arm.

    Science.gov (United States)

    De Groote, Isabelle

    2011-10-01

    Neanderthal forearms have been described as being very powerful. Different individual features in the lower arm bones have been described to distinguish Neanderthals from modern humans. In this study, the overall morphology of the radius and ulna is considered, and morphological differences among Neanderthals, Upper Paleolithic Homo sapiens and recent H. sapiens are described. Comparisons among populations were made using a combination of 3D geometric morphometrics and standard multivariate methods. Comparative material included all available complete radii and ulnae from Neanderthals, early H. sapiens and archaeological and recent human populations, representing a wide geographical and lifestyle range. There are few differences among the populations when features are considered individually. Neanderthals and early H. sapiens fell within the range of modern human variation. When the suite of measurements and shapes were analyzed, differences and similarities became apparent. The Neanderthal radius is more laterally curved, has a more medially placed radial tuberosity, a longer radial neck, a more antero-posteriorly ovoid head and a well-developed proximal interosseous crest. The Neanderthal ulna has a more anterior facing trochlear notch, a lower M. brachialis insertion, larger relative mid-shaft size and a more medio-lateral and antero-posterior sinusoidal shaft. The Neanderthal lower arm morphology reflects a strong cold-adapted short forearm. The forearms of H. sapiens are less powerful in pronation and supination. Many differences between Neanderthals and H. sapiens can be explained as a secondary consequence of the hyper-polar body proportions of the Neanderthals, but also as retentions of the primitive condition of other hominoids. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Have Third-World Arms Industries Reduced Arms Imports?

    OpenAIRE

    Looney, R.E.

    1989-01-01

    Current Research on Peace and Violence, no. 1, 1989. Refereed Journal Article In 1945 only Argentina, Brazil, India and South Africa in the Third World possessed domestic arms industries which produced weapons systems other than small arms and ammunition (SIPRI, 1987, 76).

  16. THE INFLUENCE OF LOWER LIMB MOVEMENT ON UPPER LIMB MOVEMENT SYMMETRY WHILE SWIMMING THE BREASTSTROKE

    Directory of Open Access Journals (Sweden)

    M. Jaszczak

    2011-09-01

    Full Text Available This study 1 examined the influence of lower limb movement on upper limb movement symmetry, 2 determined the part of the propulsion phase displaying the greatest hand movement asymmetry, 3 diagnosed the range of upper limb propulsion phase which is the most prone to the influence of the lower limbs while swimming the breaststroke. Twenty-four participants took part in two tests. Half of them performed an asymmetrical leg movement. The propulsion in the first test was generated by four limbs while in the second one only by the upper limbs. The pressure differentials exerted by the water on the back and on the palm of the right and left hand were measured. Then, the asymmetry coefficient of the hand movement was determined. No changes in the level of the asymmetry index in participants performing correct (symmetrical lower limb movement were observed. Incorrect (asymmetrical leg motion resulted in an increase of hand asymmetry. It could be concluded that lower limb faults neutralize upper limb performance when swimming on a rectilinear path. However, most asymmetrical arm performance should be identified with the conversion of propulsion into recovery. Nevertheless, its proneness to influence improper leg performance might be expected at the beginning of arm propulsion.

  17. Nuclear Arms Race and Environment

    OpenAIRE

    Li, Anpeng

    2012-01-01

    This paper introduces a new factor, environment, into nuclear arms race model. In this model, nuclear weapons produce larger defense power compared with conventional arms, but hurt the environment meanwhile. In the global welfare maximum level, both conventional and nuclear weapons budget are zero. However, the competitive equilibrium may not achieve the optimum. I give the condition to jump out of the prisoner's dilemma.

  18. Arménie

    Directory of Open Access Journals (Sweden)

    François Verdier

    2012-04-01

    Full Text Available L’Arménie est une petite république du Caucase, à la limite sud–est de l’Europe, qui a gagné son autonomie en 1990 après l’ouverture du bloc soviétique. Le nouveau Ministère du Patrimoine a sollicité la coopération de la France pour mettre en place une nouvelle politique culturelle. Tout d’abord, une évaluation sur place de la situation dans les domaines des monuments historiques, de l’archéologie et de l’Inventaire a permis d’envisager les réponses à proposer. Pour la demande d’informatisation des dossiers d’inventaire déjà réalisés sous l’autorité de l’Académie de Saint–Petersbourg, nous avons proposé de former des chercheurs arméniens aux méthodes et techniques de l’Inventaire général. L’accueil d’une stagiaire pendant trois mois au service régional de l’Inventaire de Haute–Normandie a été suivi par la mise en place d’un équipement informatique à Yérévan, puis par l’accueil et la formation de techniciens informaticiens et photographes arméniens. De retour dans leur pays ils ont commencé à remettre en place un service d’inventaire dont le programme comprend la création d’une base de données patrimoniales, le recensement de la ville de Yérévan, la numérisation d’images pour la publication d’un indicateur du patrimoine et la préparation de dossiers de protection au titre du patrimoine mondial.The Armenian heritage comprises both archaeological remains of towns destroyed by never–ending wars and a number of old churches from the eleventh and twelfth centuries. Yerevan, the capital of Armenia, was founded three thousand years ago and is one of Europe’s oldest capitals. From 1925 it has developed according to an ambitious urban planning project. After the major political upheavals of 1991, a special ministry was created to look after the architectural and movable heritage of the country and to promote the Armenian national identity. A mission in Yerevan was

  19. An induction sensor for measuring rectilinear movements of substantial length

    International Nuclear Information System (INIS)

    Jaudou, Yves.

    1973-01-01

    The invention is characterized in that it comprises the steps of making one end of a magnetic core integral with the objet, the movements of which are to be measured. The core has the shape of an isoscele prism the base surface of which slides within two aligned coils contained in two adjacent arms of an A-C operated Wheatstone bridge. The impedances in the W-bridge other two arms is adjusted in order that the Wheatstone bridge be balanced at a given position of the object. The movement of the object is measured from the latter given position through the potential difference, proportional to said movement developed between two opposite apices E and D of the bridge, the latter being fed with AC between the other two apices (A and B). This can be applied to the measurement of the movements of irradiation capsules in a nuclear reactor [fr

  20. Interface Based on Electrooculography for Velocity Control of a Robot Arm

    Directory of Open Access Journals (Sweden)

    Eduardo Iáñez

    2010-01-01

    Full Text Available This paper describes a technique based on electrooculography to control a robot arm. This technique detects the movement of the eyes, measuring the difference of potential between the cornea and the retina by placing electrodes around the ocular area. The processing algorithm developed to obtain the position of the eye at the blink of the user is explained. The output of the processing algorithm offers, apart from the direction, four different values (zero to three to control the velocity of the robot arm according to how much the user is looking in one direction. This allows controlling two degrees of freedom of a robot arm with the eyes movement. The blink has been used to mark some targets in tests. In this paper, the experimental results obtained with a real robot arm are shown.

  1. Self-recognition mechanism between skin and suckers prevents octopus arms from interfering with each other.

    Science.gov (United States)

    Nesher, Nir; Levy, Guy; Grasso, Frank W; Hochner, Binyamin

    2014-06-02

    Controlling movements of flexible arms is a challenging task for the octopus because of the virtually infinite number of degrees of freedom (DOFs) [1, 2]. Octopuses simplify this control by using stereotypical motion patterns that reduce the DOFs, in the control space, to a workable few [2]. These movements are triggered by the brain and are generated by motor programs embedded in the peripheral neuromuscular system of the arm [3-5]. The hundreds of suckers along each arm have a tendency to stick to almost any object they contact [6-9]. The existence of this reflex could pose significant problems with unplanned interactions between the arms if not appropriately managed. This problem is likely to be accentuated because it is accepted that octopuses are "not aware of their arms" [10-14]. Here we report of a self-recognition mechanism that has a novel role in motor control, restraining the arms from interfering with each other. We show that the suckers of amputated arms never attach to octopus skin because a chemical in the skin inhibits the attachment reflex of the suckers. The peripheral mechanism appears to be overridden by central control because, in contrast to amputated arms, behaving octopuses sometime grab amputated arms. Surprisingly, octopuses seem to identify their own amputated arms, as they treat arms of other octopuses like food more often than their own. This self-recognition mechanism is a novel peripheral component in the embodied organization of the adaptive interactions between the octopus's brain, body, and environment [15, 16]. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. International security and arms control

    International Nuclear Information System (INIS)

    Ekeus, R.

    2000-01-01

    The end of the cold war also ended the focus on the bilateral approach to arms control and disarmament. Key concepts of security needed to be revisited, along with their implications for the disarmament and arms control agenda. Though there is currently a unipolar global security environment, there remain important tasks on the multilateral arms control agenda. The major task is that of reducing and eliminating weapons of mass destruction, especially nuclear weapons. The author contends that maintaining reliance on the nuclear-weapons option makes little sense in a time when the major Powers are strengthening their partnerships in economics, trade, peacemaking and building. (author)

  3. Constraint-induced movement therapy: some thoughts about theories and evidence

    NARCIS (Netherlands)

    van der Lee, Johanna H.

    2003-01-01

    Constraint-Induced Movement Therapy (CIMT) is a type of treatment for hemiparetic stroke patients in which the patient is strongly encouraged to use the affected arm. One way of doing this is to immobilise the unaffected arm. This treatment is meant to help patients overcome 'learned non-use'. The

  4. Exemplar-based Parametric Hidden Markov Models for Recognition and Synthesis of Movements

    DEFF Research Database (Denmark)

    Herzog, Dennis; Krüger, Volker; Grest, Daniel

    2007-01-01

    A common problem in movement recognition is the recognition of movements of a particular type. E.g. pointing movements are of a particular type but differ in terms of the pointing direction. Arm movements with the goal of reaching out and grasping an object are of a particular type but differ...... are carried out through locally linear interpolation of the exemplar movements. Experiments are performed with pointing and grasping movements. Synthesis is done based on the object position as parameterization. In case of the recognition, the coordinates of the grasped or pointed at object are recovered. Our...

  5. Illusory sensation of movement induced by repetitive transcranial magnetic stimulation

    DEFF Research Database (Denmark)

    Christensen, Mark Schram; Lundbye-Jensen, Jesper; Grey, Michael James

    2010-01-01

    Human movement sense relies on both somatosensory feedback and on knowledge of the motor commands used to produce the movement. We have induced a movement illusion using repetitive transcranial magnetic stimulation over primary motor cortex and dorsal premotor cortex in the absence of limb movement...... and its associated somatosensory feedback. Afferent and efferent neural signalling was abolished in the arm with ischemic nerve block, and in the leg with spinal nerve block. Movement sensation was assessed following trains of high-frequency repetitive transcranial magnetic stimulation applied over...... premotor cortex stimulation was less affected by sensory and motor deprivation than was primary motor cortex stimulation. We propose that repetitive transcranial magnetic stimulation over dorsal premotor cortex produces a corollary discharge that is perceived as movement....

  6. Experimental Test Rig for Optimal Control of Flexible Space Robotic Arms

    Science.gov (United States)

    2016-12-01

    the test bed design. A single link arm with a torsional, helical spring at the base was finalized to investigate the effects of coupling due to...test bed design. A single link arm with a torsional, helical spring at the base was finalized to investigate the effects of coupling due to movement...Source: [4]. A challenge with space systems is that it costs a lot of money to put a satellite or spacecraft into space. Estimates to send one kilogram

  7. Controller design for flexible, distributed parameter mechanical arms via combined state space and frequency domain techniques

    Science.gov (United States)

    Book, W. J.; Majett, M.

    1982-01-01

    The potential benefits of the ability to control more flexible mechanical arms are discussed. A justification is made in terms of speed of movement. A new controller design procedure is then developed to provide this capability. It uses both a frequency domain representation and a state variable representation of the arm model. The frequency domain model is used to update the modal state variable model to insure decoupled states. The technique is applied to a simple example with encouraging results.

  8. Reach-to-grasp movement as a minimization process.

    Science.gov (United States)

    Yang, Fang; Feldman, Anatol G

    2010-02-01

    It is known that hand transport and grasping are functionally different but spatially coordinated components of reach-to-grasp (RTG) movements. As an extension of this notion, we suggested that body segments involved in RTG movements are controlled as a coherent ensemble by a global minimization process associated with the necessity for the hand to reach the motor goal. Different RTG components emerge following this process without pre-programming. Specifically, the minimization process may result from the tendency of neuromuscular elements to diminish the spatial gap between the actual arm-hand configuration and its virtual (referent) configuration specified by the brain. The referent configuration is specified depending on the object shape, localization, and orientation. Since the minimization process is gradual, it can be interrupted and resumed following mechanical perturbations, at any phase during RTG movements, including hand closure. To test this prediction of the minimization hypothesis, we asked subjects to reach and grasp a cube placed within the reach of the arm. Vision was prevented during movement until the hand returned to its initial position. As predicted, by arresting wrist motion at different points of hand transport in randomly selected trials, it was possible to halt changes in hand aperture at any phase, not only during hand opening but also during hand closure. Aperture changes resumed soon after the wrist was released. Another test of the minimization hypothesis was made in RTG movements to an object placed beyond the reach of the arm. It has previously been shown (Rossi et al. in J Physiol 538:659-671, 2002) that in such movements, the trunk motion begins to contribute to hand transport only after a critical phase when the shifts in the referent arm configuration have finished (at about the time when hand velocity is maximal). The minimization rule suggests that when the virtual contribution of the arm to hand transport is completed

  9. Technology and the arms race

    International Nuclear Information System (INIS)

    MacKenzie, D.

    1988-01-01

    This article makes a review of the book Innovation and the Arms Race: How the United States and the Soviet Union Develop New Military Technologies written by Matthew Evangelista. For at least the last two decades, scholars have struggled to come to grips with the role of technological change in the arms race. Possible relationships between theories on technology and politics are examined. The contrasts between U.S. and Soviet approaches are highlighted

  10. Changing patterns of arms transfers

    International Nuclear Information System (INIS)

    Wulf, H.

    1998-01-01

    Three factors in the international system have been of importance for the trade of arms: the role of the main actors on the supply side and since 1970 on the demand side, the permanently increasing importance of economics, and the balance trade, industrial capacity and jobs in supplier countries and purchasing power of potential importers. Two political events in 1991 had lasting effect on the development of the trade in arms: the dissolution of Soviet Union and the Gulf War

  11. Unequal-Arms Michelson Interferometers

    Science.gov (United States)

    Tinto, Massimo; Armstrong, J. W.

    2000-01-01

    Michelson interferometers allow phase measurements many orders of magnitude below the phase stability of the laser light injected into their two almost equal-length arms. If, however, the two arms are unequal, the laser fluctuations can not be removed by simply recombining the two beams. This is because the laser jitters experience different time delays in the two arms, and therefore can not cancel at the photo detector. We present here a method for achieving exact laser noise cancellation, even in an unequal-arm interferometer. The method presented in this paper requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam. By linearly combining the two data sets with themselves, after they have been properly time shifted, we show that it is possible to construct a new data set that is free of laser fluctuations. An application of this technique to future planned space-based laser interferometer detector3 of gravitational radiation is discussed.

  12. EMG-Based Continuous and Simultaneous Estimation of Arm Kinematics in Able-Bodied Individuals and Stroke Survivors

    Directory of Open Access Journals (Sweden)

    Jie Liu

    2017-08-01

    Full Text Available Among the potential biological signals for human-machine interactions (brain, nerve, and muscle signals, electromyography (EMG widely used in clinical setting can be obtained non-invasively as motor commands to control movements. The aim of this study was to develop a model for continuous and simultaneous decoding of multi-joint dynamic arm movements based on multi-channel surface EMG signals crossing the joints, leading to application of myoelectrically controlled exoskeleton robots for upper-limb rehabilitation. Twenty subjects were recruited for this study including 10 stroke subjects and 10 able-bodied subjects. The subjects performed free arm reaching movements in the horizontal plane with an exoskeleton robot. The shoulder, elbow and wrist movements and surface EMG signals from six muscles crossing the three joints were recorded. A non-linear autoregressive exogenous (NARX model was developed to continuously decode the shoulder, elbow and wrist movements based solely on the EMG signals. The shoulder, elbow and wrist movements were decoded accurately based only on the EMG inputs in all the subjects, with the variance accounted for (VAF > 98% for all three joints. The proposed approach is capable of simultaneously and continuously decoding multi-joint movements of the human arm by taking into account the non-linear mappings between the muscle EMGs and joint movements, which may provide less effortful control of robotic exoskeletons for rehabilitation training of individuals with neurological disorders and arm impairment.

  13. Flexible kinesthetic distance perception: when do your arms tell you how far you have walked?

    Science.gov (United States)

    Harrison, Steven J; Kuznetsov, Nikita; Breheim, Samuel

    2013-01-01

    Given the flexible organization of locomotion evidenced in the many ways the limbs can be coordinated, the authors explored the potentially correspondingly flexible organization of nonvisual (kinesthetic) distance perception. As kinesthetic distance perception is known to be affected by how the limbs are coordinated, the authors probed the potential perceptual contribution of the arms during locomotion by manipulating arm-leg coordination patterns in blind-walked distance-matching tasks. Whereas manipulation of arm-leg coordination for walking with free-swinging arms had no observable perceptual consequences, comparable manipulation for walking with hiking poles did affect distance matching. These results suggest that under conditions in which the arms act to propel the body (e.g., crawling or stair-climbing) a person's nonvisual sense of movement is conveyed in the coordinated actions of all four limbs.

  14. Stereotypic movement disorder

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001548.htm Stereotypic movement disorder To use the sharing features on this page, please enable JavaScript. Stereotypic movement disorder is a condition in which a person makes ...

  15. Eye Movement Disorders

    Science.gov (United States)

    ... work properly. There are many kinds of eye movement disorders. Two common ones are Strabismus - a disorder ... in "crossed eyes" or "walleye." Nystagmus - fast, uncontrollable movements of the eyes, sometimes called "dancing eyes" Some ...

  16. Overview of Movement Disorders

    Science.gov (United States)

    ... of Delirium Additional Content Medical News Overview of Movement Disorders By Hector A. Gonzalez-Usigli, MD, Professor ... Neurology, HE UMAE Centro Médico Nacional de Occidente; Movement Disorders Clinic, Neurology at IMSS Alberto Espay, MD, ...

  17. Independence of Movement Preparation and Movement Initiation.

    Science.gov (United States)

    Haith, Adrian M; Pakpoor, Jina; Krakauer, John W

    2016-03-09

    Initiating a movement in response to a visual stimulus takes significantly longer than might be expected on the basis of neural transmission delays, but it is unclear why. In a visually guided reaching task, we forced human participants to move at lower-than-normal reaction times to test whether normal reaction times are strictly necessary for accurate movement. We found that participants were, in fact, capable of moving accurately ∼80 ms earlier than their reaction times would suggest. Reaction times thus include a seemingly unnecessary delay that accounts for approximately one-third of their duration. Close examination of participants' behavior in conventional reaction-time conditions revealed that they generated occasional, spontaneous errors in trials in which their reaction time was unusually short. The pattern of these errors could be well accounted for by a simple model in which the timing of movement initiation is independent of the timing of movement preparation. This independence provides an explanation for why reaction times are usually so sluggish: delaying the mean time of movement initiation relative to preparation reduces the risk that a movement will be initiated before it has been appropriately prepared. Our results suggest that preparation and initiation of movement are mechanistically independent and may have a distinct neural basis. The results also demonstrate that, even in strongly stimulus-driven tasks, presentation of a stimulus does not directly trigger a movement. Rather, the stimulus appears to trigger an internal decision whether to make a movement, reflecting a volitional rather than reactive mode of control. Copyright © 2016 the authors 0270-6474/16/363007-10$15.00/0.

  18. Movement and Space

    DEFF Research Database (Denmark)

    Riisgaard Hansen, Thomas; Eriksson, Eva; Lykke-Olesen, Andreas

    2005-01-01

    In this paper we explore the space in which movement based interaction takes place. We have in several projects explored how fixed and mobile cameras can be used in movement based interaction and will shortly describe these projects. Based on our experience with working with movement......-based interaction we will briefly introduce and discuss how learning, mapping and multi-user interaction are important when designing movement based interaction....

  19. Recent crustal movements

    Science.gov (United States)

    Maelzer, H.

    Calculation of temporal height changes for the determination of recent vertical crustal movements in northern, western, and southern Germany is described. Precise geodetic measurements and their analysis for the determination of recent crustal movements in north-eastern Iceland, western Venezuela, and central Peru are described. Determination of recent vertical crustal movements by leveling and gravity data; geodetic modeling of deformations and recent crustal movements; geodetic modeling of plate motions; and instrumental developments in geodetic measuring are discussed.

  20. Steps for arm and trunk actions of overhead forehand stroke used in badminton games across skill levels.

    Science.gov (United States)

    Wang, Jianyu; Liu, Wenhao; Moffit, Jeffrey

    2009-08-01

    The purpose of this study was to examine arm and trunk actions in overhead forehand strokes used in badminton games across skill levels. The participants were 80 students (40 boys, 40 girls) who were randomly selected from video recordings of 300 students ages 16 to 19 years. The videotaped performances of overhead forehand strokes were coded based on three steps of arm action (elbow flexion, elbow and humeral flexion, and upward backswing) and three steps of trunk action (no trunk action, forward-backward movement, and trunk rotation). Students across the four skill levels exhibited different patterns of arm and trunk actions. Students at advanced levels used more mature arm and trunk actions.

  1. Social movements and science

    DEFF Research Database (Denmark)

    Jamison, Andrew

    2006-01-01

    The article examines the role of social movements in the development of scientific knowledge. Interactions between social movements and science in broad, historical terms are discussed. The relations between the new social movements of the 1960s and 1970s and changes in the contemporary scientific...

  2. Composite body movements modulate numerical cognition: Evidence from the motion–numerical compatibility effect

    Directory of Open Access Journals (Sweden)

    Xiaorong eCheng

    2015-11-01

    Full Text Available A recent hierarchical model of numerical processing, initiated by Fischer and Brugger (2011 and Fisher (2012, suggested that situated factors, such as different body postures and body movements, can influence the magnitude representation and bias numerical processing. Indeed, Loetscher and colleagues (2008 found that participants’ behavior in a random number generation (RNG task was biased by head rotations. More small numbers were reported after leftward than rightward head turns, i.e. a motion–numerical compatibility effect. Here, by carrying out two experiments, we explored whether similar motion–numerical compatibility effects exist for movements of other important body components, e.g. arms, and for composite body movements as well, which are basis for complex human activities in many ecologically meaningful situations. In Experiment 1, a motion-numerical compatibility effect was observed for lateral rotations of two body components, i.e., the head and arms. Relatively large numbers were reported after making rightward compared to leftward movements for both lateral head and arm turns. The motion-numerical compatibility effect was observed again in Experiment 2 when participants were asked to perform composite body movements of congruent movement directions, e.g., simultaneous head left turns and arm left turns. However, it disappeared when the movement directions were incongruent, e.g., simultaneous head left turns and arm right turns. Taken together, our results extended Loetscher et al.'s (2008 finding by demonstrating that their effect is effector-general and exists for arm movements. Moreover, our study reveals for the first time that the impact of spatial information on numerical processing induced by each of the two sensorimotor-based situated factors, e.g., a lateral head turn and a lateral arm turn, can cancel each other out.

  3. Arm Motion Recognition and Exercise Coaching System for Remote Interaction

    Directory of Open Access Journals (Sweden)

    Hong Zeng

    2016-01-01

    Full Text Available Arm motion recognition and its related applications have become a promising human computer interaction modal due to the rapid integration of numerical sensors in modern mobile-phones. We implement a mobile-phone-based arm motion recognition and exercise coaching system that can help people carrying mobile-phones to do body exercising anywhere at any time, especially for the persons that have very limited spare time and are constantly traveling across cities. We first design improved k-means algorithm to cluster the collecting 3-axis acceleration and gyroscope data of person actions into basic motions. A learning method based on Hidden Markov Model is then designed to classify and recognize continuous arm motions of both learners and coaches, which also measures the action similarities between the persons. We implement the system on MIUI 2S mobile-phone and evaluate the system performance and its accuracy of recognition.

  4. Algorithms for Unequal-Arm Michelson Interferometers

    Science.gov (United States)

    Giampieri, Giacomo; Hellings, Ronald W.; Tinto, Massimo; Bender, Peter L.; Faller, James E.

    1994-01-01

    A method of data acquisition and data analysis is described in which the performance of Michelson-type interferometers with unequal arms can be made nearly the same as interferometers with equal arms. The method requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam.

  5. Arm trajectories and writing strategy in healthy children

    Directory of Open Access Journals (Sweden)

    Chiappedi Matteo

    2012-11-01

    Full Text Available Abstract Background Evaluation of elementary writing skills in children is usually obtained with high resolution (and high cost techniques or with low resolution pen-and-paper tests. In this observational study we tested a quantitative method to obtain normative data to describe arm movement during a writing precursor gesture. Methods We recruited 226 healthy children (mean age 9,1 years [range: 6.3 – 11.4 years], attending primary schools belonging to the “Istituto Comprensivo” of Rivanazzano Terme (Pavia. We asked to drive a cursor through a polygonal path (labyrinth projected in front of them using a wireless mouse. Dartfish™ video analysis software was used to elaborate images and Excel™, MedCalc™ and Statistica 7™ to analyze values of shoulder, elbow and wrist ranges of motion, arm trajectories, execution times and gesture accuracy. Results Differences seen in motor strategies, when divided according to attended class, suggest a proximal-distal maturation of motor control. Obtained values were not significantly correlated with variables such as gender, ethnicity or cognitive functioning. Conclusions This type of approach to a study of arm movement during childhood represents a valid alternative to other tests, considering that it can differentiate children who perform similarly in the VMI test and is non-invasive, low-cost and easily reproducible.

  6. Upper limb movement analysis during gait in multiple sclerosis patients.

    Science.gov (United States)

    Elsworth-Edelsten, Charlotte; Bonnefoy-Mazure, Alice; Laidet, Magali; Armand, Stephane; Assal, Frederic; Lalive, Patrice; Allali, Gilles

    2017-08-01

    Gait disorders in multiple sclerosis (MS) are well studied; however, no previous study has described upper limb movements during gait. However, upper limb movements have an important role during locomotion and can be altered in MS patients due to direct MS lesions or mechanisms of compensation. The aim of this study was to describe the arm movements during gait in a population of MS patients with low disability compared with a healthy control group. In this observational study we analyzed the arm movements during gait in 52 outpatients (mean age: 39.7±9.6years, female: 40%) with relapsing-remitting MS with low disability (mean EDSS: 2±1) and 25 healthy age-matched controls using a 3-dimension gait analysis. MS patients walked slower, with increased mean elbow flexion and decreased amplitude of elbow flexion (ROM) compared to the control group, whereas shoulder and hand movements were similar to controls. These differences were not explained by age or disability. Upper limb alterations in movement during gait in MS patients with low disability can be characterized by an increase in mean elbow flexion and a decrease in amplitude (ROM) for elbow flexion/extension. This upper limb movement pattern should be considered as a new component of gait disorders in MS and may reflect subtle motor deficits or the use of compensatory mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. JINR rapid communications

    International Nuclear Information System (INIS)

    1997-01-01

    The present collection of rapid communications from JINR, Dubna, contains nine separate reports on effects arising from charged particles overcoming of the light velocity barrier, deformable templates for circle recognition, scintillation detectors for precise time measurements, atomic form factors and incoherent scattering functions of atoms and ions with the number of electrons N ≤ 10, experimental set-up ANOMALON for measurement of relativistic nuclear fragmentation cross sections, superconducting dipole magnet for ALICE dimuon arm spectrometer, analysis of transverse mass dependence of Bose-Einstein correlation radii using the DELPHI data, low-energy theorem in softly broken supersymmetry and study of the characteristics of particles in reactions π - , p, d, He, C + C with the total disintegration on carbon nucleus

  8. Proprioceptive Interaction between the Two Arms in a Single-Arm Pointing Task.

    Directory of Open Access Journals (Sweden)

    Kazuyoshi Kigawa

    Full Text Available Proprioceptive signals coming from both arms are used to determine the perceived position of one arm in a two-arm matching task. Here, we examined whether the perceived position of one arm is affected by proprioceptive signals from the other arm in a one-arm pointing task in which participants specified the perceived position of an unseen reference arm with an indicator paddle. Both arms were hidden from the participant's view throughout the study. In Experiment 1, with both arms placed in front of the body, the participants received 70-80 Hz vibration to the elbow flexors of the reference arm (= right arm to induce the illusion of elbow extension. This extension illusion was compared with that when the left arm elbow flexors were vibrated or not. The degree of the vibration-induced extension illusion of the right arm was reduced in the presence of left arm vibration. In Experiment 2, we found that this kinesthetic interaction between the two arms did not occur when the left arm was vibrated in an abducted position. In Experiment 3, the vibration-induced extension illusion of one arm was fully developed when this arm was placed at an abducted position, indicating that the brain receives increased proprioceptive input from a vibrated arm even if the arm was abducted. Our results suggest that proprioceptive interaction between the two arms occurs in a one-arm pointing task when the two arms are aligned with one another. The position sense of one arm measured using a pointer appears to include the influences of incoming information from the other arm when both arms were placed in front of the body and parallel to one another.

  9. Programming and execution of movement in Parkinson's disease.

    Science.gov (United States)

    Sheridan, M R; Flowers, K A; Hurrell, J

    1987-10-01

    Programming and execution of arm movements in Parkinson's disease were investigated in choice and simple reaction time (RT) situations in which subjects made aimed movements at a target. A no-aiming condition was also studied. Reaction time was fractionated using surface EMG recording into premotor (central) and motor (peripheral) components. Premotor RT was found to be greater for parkinsonian patients than normal age-matched controls in the simple RT condition, but not in the choice condition. This effect did not depend on the parameters of the impending movement. Thus, paradoxically, parkinsonian patients were not inherently slower at initiating aiming movements from the starting position, but seemed unable to use advance information concerning motor task demands to speed up movement initiation. For both groups, low velocity movements took longer to initiate than high velocity ones. In the no-aiming condition parkinsonian RTs were markedly shorter than when aiming, but were still significantly longer than control RTs. Motor RT was constant across all conditions and was not different for patient and control subjects. In all conditions, parkinsonian movements were around 37% slower than control movements, and their movement times were more variable, the differences showing up early on in the movement, that is, during the initial ballistic phase. The within-subject variability of movement endpoints was also greater in patients. The motor dysfunction displayed in Parkinson's disease involves a number of components: (1) a basic central problem with simply initiating movements, even when minimal programming is required (no-aiming condition); (2) difficulty in maintaining computed forces for motor programs over time (simple RT condition); (3) a basic slowness of movement (bradykinesia) in all conditions; and (4) increased variability of movement in both time and space, presumably caused by inherent variability in force production.

  10. Design and fabrication of an articulated four axes microrobot arm

    Science.gov (United States)

    Zhang, Ruoshi; Yang, Zhong; Wei, Danming; Popa, Dan O.

    2017-05-01

    In order to carry out nanomanufacturing tasks, a microrobot requires both high precision and high reliability over prolonged periods of time. Articulated Four-Axis Microrobots (AFAM) have been introduced a decade ago as millimetric microrobots capable of carrying out nanoscale tasks. The original robot design relied on a Micro Electro Mechanical (MEMS) actuator bank positioned onto a Silicon substrate, and an assembled arm mechanically coupled to the actuators through a cable. Movement of two thermal actuator banks positions the AFAM's end effector in 3-Dimensional space with approximately 75 microns workspace and 50 nm repeatability. However, failure of the AFAM's cable mechanism was observed after less than 1 million cycles. In this paper, we propose a novel arm mechanism for AFAM that improve its performance. The design presented in this article substitutes the "wire-gluing" cable with an anchored electrostatic actuator, and therefore it simplifies assembly requirements, reduces overall footprint of the microrobot, and achieves higher operating frequency. Simulation results are presented for a rotary electrostatic comb drive as basis for the microrobot arm with overall dimensions of 2 mm × 2 mm. The AFAM arm cantilever is 1 mm long to achieve a workspace of dimension of 75 microns along the vertical axis. Experimental evaluation of the design was accomplished using a prototype fabricated on a silicon on insulator (SOI) wafer processed with the deep reactive ion etching (DRIE) process.

  11. Neck and arm pain syndromes

    DEFF Research Database (Denmark)

    de las Peñas, César Fernández; Cleland, Joshua; Huijbregts, Peter

    approaches.It uniquely addresses the expanding role of the various health care professions which require increased knowledge and skills in screening for contra-indications and recognizing the need for medical-surgical referral. Neck and Arm Pain Syndromes also stresses the integration of experiential......The first of its kind, Neck and Arm Pain Syndromes is a comprehensive evidence- and clinical-based book, covering research-based diagnosis, prognosis and management of neuromusculoskeletal pathologies and dysfunctions of the upper quadrant, including joint, muscle, myofascial and neural tissue...... of the most commonly seen pain syndromes in clinical practice over 800 illustrations demonstrating examination procedures and techniques....

  12. Corporate interests, philanthropies, and the peace movement.

    Science.gov (United States)

    Wright, T; Rodriguez, F; Waitzkin, H

    1986-01-01

    Corporate and philanthropic involvement in the peace movement is growing. In considering medical peace groups as examples, we have studied the ways that corporate and philanthropic funding have shaped the course of activism. Our methods have included: review of the Foundations Grant Index from 1974-1983; analysis of corporations' and foundations' criteria for grants in the categories of peace, arms control, and disarmament; interviews with leaders of activist organizations and with foundation officials; and our own experiences in the peace movement. Corporate interests in preventing nuclear war stem from a concern for global stability in which world markets may expand, and from a hope to frame issues posed by the peace movement in a way that will not challenge basic structures of power and finance. Several general features make peace groups respectable and attractive to philanthropies; an uncritical stance toward corporate participation in the arms race; a viewpoint that the main danger of nuclear war stems from a profound, bilateral conflict between the United States and the Soviet Union; and a single-issue focus that does not deal with the many related problems reflecting the injustices of capitalism. The two major medical groups working for peace, Physicians for Social Responsibility (PSR) and International Physicians for the Prevention of Nuclear War (IPPNW), have accomplished many goals; however, their adherence to subtle criteria of respectability and their dependence on philanthropic funding have limited the scope of their activism. The struggle for peace can not succeed without fundamental changes in the corporate system that initiates, maintains, and promotes the arms race.

  13. Translational control of a graphically simulated robot arm by kinematic rate equations that overcome elbow joint singularity

    Science.gov (United States)

    Barker, L. K.; Houck, J. A.; Carzoo, S. W.

    1984-01-01

    An operator commands a robot hand to move in a certain direction relative to its own axis system by specifying a velocity in that direction. This velocity command is then resolved into individual joint rotational velocities in the robot arm to effect the motion. However, the usual resolved-rate equations become singular when the robot arm is straightened. To overcome this elbow joint singularity, equations were developed which allow continued translational control of the robot hand even though the robot arm is (or is nearly) fully extended. A feature of the equations near full arm extension is that an operator simply extends and retracts the robot arm to reverse the direction of the elbow bend (difficult maneuver for the usual resolved-rate equations). Results show successful movement of a graphically simulated robot arm.

  14. A virtual reality system for arm and hand rehabilitation

    Science.gov (United States)

    Luo, Zhiqiang; Lim, Chee Kian; Chen, I.-Ming; Yeo, Song Huat

    2011-03-01

    This paper presents a virtual reality (VR) system for upper limb rehabilitation. The system incorporates two motion track components, the Arm Suit and the Smart Glove which are composed of a range of the optical linear encoders (OLE) and the inertial measurement units (IMU), and two interactive practice applications designed for driving users to perform the required functional and non-functional motor recovery tasks. We describe the technique details about the two motion track components and the rational to design two practice applications. The experiment results show that, compared with the marker-based tracking system, the Arm Suit can accurately track the elbow and wrist positions. The repeatability of the Smart Glove on measuring the five fingers' movement can be satisfied. Given the low cost, high accuracy and easy installation, the system thus promises to be a valuable complement to conventional therapeutic programs offered in rehabilitation clinics and at home.

  15. Estimation of Human Arm Joints Using Two Wireless Sensors in Robotic Rehabilitation Tasks

    Directory of Open Access Journals (Sweden)

    Arturo Bertomeu-Motos

    2015-12-01

    Full Text Available This paper presents a novel kinematic reconstruction of the human arm chain with five degrees of freedom and the estimation of the shoulder location during rehabilitation therapy assisted by end-effector robotic devices. This algorithm is based on the pseudoinverse of the Jacobian through the acceleration of the upper arm, measured using an accelerometer, and the orientation of the shoulder, estimated with a magnetic angular rate and gravity (MARG device. The results show a high accuracy in terms of arm joints and shoulder movement with respect to the real arm measured through an optoelectronic system. Furthermore, the range of motion (ROM of 50 healthy subjects is studied from two different trials, one trying to avoid shoulder movements and the second one forcing them. Moreover, the shoulder movement in the second trial is also estimated accurately. Besides the fact that the posture of the patient can be corrected during the exercise, the therapist could use the presented algorithm as an objective assessment tool. In conclusion, the joints’ estimation enables a better adjustment of the therapy, taking into account the needs of the patient, and consequently, the arm motion improves faster.

  16. Nuclear physicist, arms control advocate

    CERN Multimedia

    Chang, K

    2002-01-01

    Victor F. Weisskopf, a nuclear physicist who worked on the Manhattan Project to build the first atomic bomb in World War II and later became an ardent advocate of arms control, died Monday at his home in Newton, MA, USA. He was 93 (1 page).

  17. Taxation, stateness and armed groups

    DEFF Research Database (Denmark)

    Hoffmann, Kasper; Vlassenroot, Koen; Marchais, Gauthier

    2016-01-01

    of authority and practices of rule that originate in the colonial era. In particular, the article shows that by appealing to both local customary and national forms of political community and citizenship, armed groups are able to assume public authority to tax civilians. However, their public authority may...

  18. Distinguishing targets in armed conflict

    African Journals Online (AJOL)

    The main object of international humanitarian law (IHL) is the amelioration of the effect of armed conflict on the populace. It seeks to accomplish this by establishing rules that ensure that objects the destruction of which will not give military advantage e are protected; thus, such objects are not to be targeted or destroyed.

  19. How Computers are Arming biology!

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 23; Issue 1. In-vitro to In-silico - How Computers are Arming biology! Geetha Sugumaran Sushila Rajagopal. Face to Face Volume 23 Issue 1 January 2018 pp 83-102. Fulltext. Click here to view fulltext PDF. Permanent link:

  20. Robotic Arm Control Algorithm Based on Stereo Vision Using RoboRealm Vision

    Directory of Open Access Journals (Sweden)

    SZABO, R.

    2015-05-01

    Full Text Available The goal of this paper is to present a stereo computer vision algorithm intended to control a robotic arm. Specific points on the robot joints are marked and recognized in the software. Using a dedicated set of mathematic equations, the movement of the robot is continuously computed and monitored with webcams. Positioning error is finally analyzed.

  1. Robotics combined with electrical stimulation : hybrid support of arm and hand for functional training after stroke

    NARCIS (Netherlands)

    Westerveld, Ard

    2014-01-01

    Reach, grasp and release is part of many functional movements. Graying of society leads to more stroke victims and fewer health care professionals. Technology might be a solution to support certain rehabilitation therapies in future health care. Robotic systems have been developed for support of arm

  2. Robotics combined with electrical stimulation: hybrid support of arm and hand for functional training after stroke

    NARCIS (Netherlands)

    Westerveld, Ard

    2014-01-01

    Reach, grasp and release is part of many functional movements. Graying of society leads to more stroke victims and fewer health care professionals. Technology might be a solution to support certain rehabilitation therapies in future health care. Robotic systems have been developed for support of arm

  3. Posture of the arm when grasping spheres to place them elsewhere

    NARCIS (Netherlands)

    Schot, W.D.; Brenner, E.; Smeets, J.B.J.

    2010-01-01

    Despite the infinitely many ways to grasp a spherical object, regularities have been observed in the posture of the arm and the grasp orientation. In the present study, we set out to determine the factors that predict the grasp orientation and the final joint angles of reach-tograsp movements.

  4. Shaping of arm configuration space by prescription of non-Euclidean metrics with applications to human motor control

    Science.gov (United States)

    Biess, Armin

    2013-01-01

    The study of the kinematic and dynamic features of human arm movements provides insights into the computational strategies underlying human motor control. In this paper a differential geometric approach to movement control is taken by endowing arm configuration space with different non-Euclidean metric structures to study the predictions of the generalized minimum-jerk (MJ) model in the resulting Riemannian manifold for different types of human arm movements. For each metric space the solution of the generalized MJ model is given by reparametrized geodesic paths. This geodesic model is applied to a variety of motor tasks ranging from three-dimensional unconstrained movements of a four degree of freedom arm between pointlike targets to constrained movements where the hand location is confined to a surface (e.g., a sphere) or a curve (e.g., an ellipse). For the latter speed-curvature relations are derived depending on the boundary conditions imposed (periodic or nonperiodic) and the compatibility with the empirical one-third power law is shown. Based on these theoretical studies and recent experimental findings, I argue that geodesics may be an emergent property of the motor system and that the sensorimotor system may shape arm configuration space by learning metric structures through sensorimotor feedback.

  5. Spontaneous group synchronization of movements and respiratory rhythms.

    Directory of Open Access Journals (Sweden)

    Erwan Codrons

    Full Text Available We tested whether pre-assigned arm movements performed in a group setting spontaneously synchronized and whether synchronization extended to heart and respiratory rhythms. We monitored arm movements, respiration and electrocardiogram at rest and during spontaneous, music and metronome-associated arm-swinging. No directions were given on whether or how the arm swinging were to be synchronized between participants or with the external cues. Synchronization within 3 groups of 10 participants studied collectively was compared with pseudo-synchronization of 3 groups of 10 participants that underwent an identical protocol but in an individual setting. Motor synchronization was found to be higher in the collective groups than in the individuals for the metronome-associated condition. On a repetition of the protocol on the following day, motor synchronization in the collective groups extended to the spontaneous, un-cued condition. Breathing was also more synchronized in the collective groups than in the individuals, particularly at rest and in the music-associated condition. Group synchronization occurs without explicit instructions, and involves both movements and respiratory control rhythms.

  6. Movement monitoring device

    International Nuclear Information System (INIS)

    Ichikawa, Takashi; Yoneda, Yasuaki; Hanatsumi, Masaharu.

    1997-01-01

    The present invention provides a device suitable to accurate recognition for the moving state of reactor core fuels as an object to be monitored in a nuclear power plant. Namely, the device of the present invention prepares each of scheduled paths for the movement of the object to be monitored and executed moving paths along with the movement based on the information of the movement obtained from scheduled information for the movement of the reactor core fuels as a object to be monitored and the actual movement of the object to be monitored. The results of the preparation are outputted. As an output mode, (1) the results of preparation for each of the paths for movement and the results of the monitoring obtained by monitoring the state of the object to be monitored are jointed and outputted, (2) images showing each of the paths for the movement are formed, and the formed images are displayed on a screen, and (3) each of the moving paths is prepared as an image, and the image is displayed together with the image of the regions before and after the movement of the object to be monitored. In addition, obtained images of each of the paths for the movement and the monitored images obtained by monitoring the state of the object to be monitored are joined and displayed. (I.S.)

  7. Classification of movement disorders.

    Science.gov (United States)

    Fahn, Stanley

    2011-05-01

    The classification of movement disorders has evolved. Even the terminology has shifted, from an anatomical one of extrapyramidal disorders to a phenomenological one of movement disorders. The history of how this shift came about is described. The history of both the definitions and the classifications of the various neurologic conditions is then reviewed. First is a review of movement disorders as a group; then, the evolving classifications for 3 of them--parkinsonism, dystonia, and tremor--are covered in detail. Copyright © 2011 Movement Disorder Society.

  8. Sensation of Movement

    DEFF Research Database (Denmark)

    Sensation of Movement will discuss the role of sensation in the control of action, bodily self-recognition, and sense of agency. Sensing movement is dependent on a range of information received by the brain, from signalling in the peripheral sensory organs to the establishment of higher order goals....... This volume will question whether one type of information is more relevant for the ability to sense and control movements, and demonstrate the importance of integrating neuroscientific knowledge with philosophical perspectives, in order to arrive at new insights into how sensation of movement can be studied...

  9. Flying cheap : modelling the passive movement of plants and animals

    NARCIS (Netherlands)

    Treep, H.J.

    2018-01-01

    Movement of organisms is a key process in ecology, as it enables colonization and gene flow. The ongoing worldwide decline of biodiversity and the increasing pressures of climate change and habitat fragmentation, stress the importance of movement ecology research. There is rapid progress in

  10. Blood pressure measurement: one arm or both arm?

    Science.gov (United States)

    Kulkarni, Prasad K; Shekhar, Susheela; Reddy, B N; Nirmala, B C

    2011-09-01

    Guidelines for measuring blood pressure includes measurement of blood pressure on both arms but it is often ignored. Our case report aims at highlighting the need follow the guidelines. A 60 year old 59 kg weighing male asymptomatic patient without any comobidities was posted for bilateral inguinal hernia repair. The interarm blood pressure difference was discovered incidentally during his preanaesthetic evalution. On further evaluation patient was found to be having subclavian stenosis on left side which was asymptomatic. Intraoperative and post operative period was uneventful. Blood pressure measurement should be done in accordance with the stipulated guidelines. Inter arm blood pressure difference should be noted in all patients as not only for diagnosis and treatment of hypertension but also as a tool to diagnose asymptomatic peripheral vascular disesase.

  11. Exploring pedestrian movement patterns

    NARCIS (Netherlands)

    Orellana, D.A.

    2012-01-01

    The main objective of this thesis is to develop an approach for exploring, analysing and interpreting movement patterns of pedestrians interacting with the environment. This objective is broken down in sub-objectives related to four research questions. A case study of the movement of visitors in a

  12. [Dance/Movement Therapy.

    Science.gov (United States)

    Fenichel, Emily, Ed.

    1994-01-01

    This newsletter theme issue focuses on dance, play, and movement therapy for infants and toddlers with disabilities. Individual articles are: "Join My Dance: The Unique Movement Style of Each Infant and Toddler Can Invite Communication, Expression and Intervention" (Suzi Tortora); "Dynamic Play Therapy: An Integrated Expressive Arts Approach to…

  13. Dynamics of human movement

    NARCIS (Netherlands)

    Koopman, Hubertus F.J.M.

    2010-01-01

    The part of (bio)mechanics that studies the interaction of forces on the human skeletal system and its effect on the resulting movement is called rigid body dynamics. Some basic concepts are presented: A mathematical formulation to describe human movement and how this relates on the mechanical loads

  14. Controlling robot arm with the mind

    National Science Foundation

    2017-05-31

    Full Text Available Research test subjects at the University of Minnesota who were fitted with a specialized noninvasive brain cap were able to move a robotic arm just by imagining moving their own arms.

  15. Chaotic evolution of arms races

    Science.gov (United States)

    Tomochi, Masaki; Kono, Mitsuo

    1998-12-01

    A new set of model equations is proposed to describe the evolution of the arms race, by extending Richardson's model with special emphases that (1) power dependent defensive reaction or historical enmity could be a motive force to promote armaments, (2) a deterrent would suppress the growth of armaments, and (3) the defense reaction of one nation against the other nation depends nonlinearly on the difference in armaments between two. The set of equations is numerically solved to exhibit stationary, periodic, and chaotic behavior depending on the combinations of parameters involved. The chaotic evolution is realized when the economic situation of each country involved in the arms race is quite different, which is often observed in the real world.

  16. Regenerator cross arm seal assembly

    Science.gov (United States)

    Jackman, Anthony V.

    1988-01-01

    A seal assembly for disposition between a cross arm on a gas turbine engine block and a regenerator disc, the seal assembly including a platform coextensive with the cross arm, a seal and wear layer sealingly and slidingly engaging the regenerator disc, a porous and compliant support layer between the platform and the seal and wear layer porous enough to permit flow of cooling air therethrough and compliant to accommodate relative thermal growth and distortion, a dike between the seal and wear layer and the platform for preventing cross flow through the support layer between engine exhaust and pressurized air passages, and air diversion passages for directing unregenerated pressurized air through the support layer to cool the seal and wear layer and then back into the flow of regenerated pressurized air.

  17. Rapidly Progressive Quadriplegia and Encephalopathy.

    Science.gov (United States)

    Wynn, DonRaphael; McCorquodale, Donald; Peters, Angela; Juster-Switlyk, Kelsey; Smith, Gordon; Ansari, Safdar

    2016-11-01

    A woman aged 77 years was transferred to our neurocritical care unit for evaluation and treatment of rapidly progressive motor weakness and encephalopathy. Examination revealed an ability to follow simple commands only and abnormal movements, including myoclonus, tongue and orofacial dyskinesias, and opsoclonus. Imaging study findings were initially unremarkable, but when repeated, they demonstrated enhancement of the cauda equina nerve roots, trigeminal nerve, and pachymeninges. Cerebrospinal fluid examination revealed mildly elevated white blood cell count and protein levels. Serial electrodiagnostic testing demonstrated a rapidly progressive diffuse sensory motor axonopathy, and electroencephalogram findings progressed from generalized slowing to bilateral periodic lateralized epileptiform discharges. Critical details of her recent history prompted a diagnostic biopsy. Over time, the patient became completely unresponsive with no further abnormal movements and ultimately died. The differential diagnosis, pathological findings, and diagnosis are discussed with a brief review of a well-known yet rare diagnosis.

  18. Dual arm master controller concept

    International Nuclear Information System (INIS)

    Kuban, D.P.; Perkins, G.S.

    1984-01-01

    The Advanced Servomanipulator (ASM) slave was designed with an anthropomorphic stance, gear/torque tube power drives, and modular construction. These features resulted in increased inertia, friction, and backlash relative to tape-driven manipulators. Studies were performed which addressed the human factors design and performance trade-offs associated with the corresponding master controller best suited for the ASM. The results of these studies, as well as the conceptual design of the dual arm master controller, are presented. 6 references, 3 figures

  19. Dual arm master controller development

    Science.gov (United States)

    Kuban, D. P.; Perkins, G. S.

    1985-01-01

    The advanced servomanipulator (ASM) slave was designed with an anthropomorphic stance gear/torque tube power drives, and modular construction. These features resulted in increased inertia, friction, and backlash relative to tape driven manipulators. Studies were performed which addressed to human factor design and performance tradeoffs associated with the corresponding master controller best suited for the ASM. The results of these studies, as well as the conceptual design of the dual arm master controller, are presented.

  20. 21 CFR 890.3640 - Arm sling.

    Science.gov (United States)

    2010-04-01

    ... arm sling is a device intended for medical purposes to immobilize the arm, by means of a fabric band... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Arm sling. 890.3640 Section 890.3640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES...

  1. Limited consensus around ARM information protection practices ...

    African Journals Online (AJOL)

    An existing enterprise IP SoP was adapted to ARM through literature analysis and produced a draft ARM SoP. The draft ARM SoP was applied in a rote fashion to a small sample of government-operated archives to identify likely areas of consensus and lack of consensus surrounding the various elements of the SoP.

  2. The MVACS Robotic Arm Camera

    Science.gov (United States)

    Keller, H. U.; Hartwig, H.; Kramm, R.; Koschny, D.; Markiewicz, W. J.; Thomas, N.; Fernades, M.; Smith, P. H.; Reynolds, R.; Lemmon, M. T.; Weinberg, J.; Marcialis, R.; Tanner, R.; Boss, B. J.; Oquest, C.; Paige, D. A.

    2001-08-01

    The Robotic Arm Camera (RAC) is one of the key instruments newly developed for the Mars Volatiles and Climate Surveyor payload of the Mars Polar Lander. This lightweight instrument employs a front lens with variable focus range and takes images at distances from 11 mm (image scale 1:1) to infinity. Color images with a resolution of better than 50 μm can be obtained to characterize the Martian soil. Spectral information of nearby objects is retrieved through illumination with blue, green, and red lamp sets. The design and performance of the camera are described in relation to the science objectives and operation. The RAC uses the same CCD detector array as the Surface Stereo Imager and shares the readout electronics with this camera. The RAC is mounted at the wrist of the Robotic Arm and can characterize the contents of the scoop, the samples of soil fed to the Thermal Evolved Gas Analyzer, the Martian surface in the vicinity of the lander, and the interior of trenches dug out by the Robotic Arm. It can also be used to take panoramic images and to retrieve stereo information with an effective baseline surpassing that of the Surface Stereo Imager by about a factor of 3.

  3. Observing human movements helps decoding environmental forces.

    Science.gov (United States)

    Zago, Myrka; La Scaleia, Barbara; Miller, William L; Lacquaniti, Francesco

    2011-11-01

    Vision of human actions can affect several features of visual motion processing, as well as the motor responses of the observer. Here, we tested the hypothesis that action observation helps decoding environmental forces during the interception of a decelerating target within a brief time window, a task intrinsically very difficult. We employed a factorial design to evaluate the effects of scene orientation (normal or inverted) and target gravity (normal or inverted). Button-press triggered the motion of a bullet, a piston, or a human arm. We found that the timing errors were smaller for upright scenes irrespective of gravity direction in the Bullet group, while the errors were smaller for the standard condition of normal scene and gravity in the Piston group. In the Arm group, instead, performance was better when the directions of scene and target gravity were concordant, irrespective of whether both were upright or inverted. These results suggest that the default viewer-centered reference frame is used with inanimate scenes, such as those of the Bullet and Piston protocols. Instead, the presence of biological movements in animate scenes (as in the Arm protocol) may help processing target kinematics under the ecological conditions of coherence between scene and target gravity directions.

  4. Performance of arm locking in LISA

    International Nuclear Information System (INIS)

    McKenzie, Kirk; Spero, Robert E.; Shaddock, Daniel A.

    2009-01-01

    For the Laser Interferometer Space Antenna (LISA) to reach its design sensitivity, the coupling of the free-running laser frequency noise to the signal readout must be reduced by more than 14 orders of magnitude. One technique employed to reduce the laser frequency noise will be arm locking, where the laser frequency is locked to the LISA arm length. In this paper we detail an implementation of arm locking. We investigate orbital effects (changing arm lengths and Doppler frequencies), the impact of errors in the Doppler knowledge that can cause pulling of the laser frequency, and the noise limit of arm locking. Laser frequency pulling is examined in two regimes: at lock acquisition and in steady state. The noise performance of arm locking is calculated with the inclusion of the dominant expected noise sources: ultrastable oscillator (clock) noise, spacecraft motion, and shot noise. We find that clock noise and spacecraft motion limit the performance of dual arm locking in the LISA science band. Studying these issues reveals that although dual arm locking [A. Sutton and D. A. Shaddock, Phys. Rev. D 78, 082001 (2008)] has advantages over single (or common) arm locking in terms of allowing high gain, it has disadvantages in both laser frequency pulling and noise performance. We address this by proposing a modification to the dual arm-locking sensor, a hybrid of common and dual arm-locking sensors. This modified dual arm-locking sensor has the laser frequency pulling characteristics and low-frequency noise coupling of common arm locking, but retains the control system advantages of dual arm locking. We present a detailed design of an arm-locking controller and perform an analysis of the expected performance when used with and without laser prestabilization. We observe that the sensor phase changes beneficially near unity-gain frequencies of the arm-locking controller, allowing a factor of 10 more gain than previously believed, without degrading stability. With a time

  5. Kinematics analysis on hinges of robot arm gripper for harmful chemical handling

    Science.gov (United States)

    Razali, Zol Bahri; Kader, Mohamed Mydin M. Abdul; Mustafa, Nurul Fahimah; Daud, Mohd Hisam

    2017-09-01

    The development of manufacturing industry is booming the application of industrial robot, and proportional to the use of robot arm. Some of the purpose of robot arm gripper is to sort things and place to the proper place. And some of the things are harmful to human, such as harmful chemical. By using robot arm to do picking and placing, it is expected to replace human tasks, as well as to reduce human from the harmful job. The problem of the robot arm gripper, most likely the problem of hinge, thus the analysis on the hinges of robot arm gripper to prevent claw is essential. By using robot arm, instead of human, is labored to do the harmful tasks and unexpected accident happen, costs and expenses in handling injured employee due to the harmful chemicals can be minimized. Thus the objective of this project is to make a kinematics analysis on the hinges of the robot arm gripper. Suitable material such as steel structure has also been selected for the construction of this hinges. This material has properties associated with compressive strength, fire resistance, corrosion and has a shape that is easy to move. Solid Works and ANSYS software is used to create animated movement on the design model and to detect deficiencies in the hinges. Detail methodology is described in this paper.

  6. Sex-selective QT prolongation during rapid eye movement sleep

    Czech Academy of Sciences Publication Activity Database

    Lanfranchi, P.; Shamsuzzaman, A. S.; Ackerman, M. J.; Kára, T.; Jurák, Pavel; Wolk, R.; Somers, V.

    2002-01-01

    Roč. 106, č. 12 (2002), s. 1488 - 1492 ISSN 0009-7322 R&D Projects: GA ČR GA102/95/0467; GA ČR GA102/02/1339 Institutional research plan: CEZ:AV0Z2065902 Keywords : sleep * sex * nervous system Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 10.255, year: 2002

  7. Islamic Puritanism Movements in Indonesia as Transnational Movements

    Directory of Open Access Journals (Sweden)

    Benny Baskara

    2017-04-01

    Full Text Available Islamic puritanism movements are the movements compelling to return to the teachings of Quran and Sunnah, as the pure teachings of Islam and abandon even abolish other teachings outside the teachings of Quran and Sunnah. The movements of Islamic puritanism can be considered as transnational movements because they spread their teachings and ideologies, create organizations, networks, and provide financial supports across nations. This paper describes Islamic puritanism movements in Indonesia and their transnational connections. Some Islamic puritanism movements in Indonesia can be considered as part of Islamic transnational movements, in which most of the movements are centered in the Middle East. In Indonesia, Islamic puritanism movements firstly appeared in the beginning of the nineteenth century, called Padri movement in West Sumatra. It was then continued to the emergence of Islamic organizations in the twentieth century. Recently, Islamic puritanism movements in Indonesia mostly take form as Salafism-Wahabism movements.

  8. The Irish Women's Movement

    OpenAIRE

    Cullen, Pauline

    2015-01-01

    Ireland’s long history of patriarchy is matched by the ongoing evolution of its women’s movements. Today’s complex, transnational feminism finds its precursor in the colonial era. The first wave of the Irish women’s movement dates from the mid-19th century, with the franchise secured for women in 1918 while still under British colonial rule. First-wave feminists played a role in the nationalist movement, but their demands were sidelined later, during the construction of a conserva...

  9. Music and movement

    OpenAIRE

    Nasev, Lence

    2012-01-01

    Rhythm is one of the fundamental elements without which music would not exist. In plays with singing, a child learns to synchronize its movements with the rhythm of music from a very early age. The skill of movement plays a major role in the learning of music and thus deserves an important place in the school curriculum. In this paper, an overview is made of the most important music pedagogues who introduced movement, and at the same time perceived its importance in learning musical conte...

  10. High precision detector robot arm system

    Science.gov (United States)

    Shu, Deming; Chu, Yong

    2017-01-31

    A method and high precision robot arm system are provided, for example, for X-ray nanodiffraction with an X-ray nanoprobe. The robot arm system includes duo-vertical-stages and a kinematic linkage system. A two-dimensional (2D) vertical plane ultra-precision robot arm supporting an X-ray detector provides positioning and manipulating of the X-ray detector. A vertical support for the 2D vertical plane robot arm includes spaced apart rails respectively engaging a first bearing structure and a second bearing structure carried by the 2D vertical plane robot arm.

  11. To Arm or Not to Arm: The Case Against Arming Vietnam and the Philippines

    Science.gov (United States)

    2015-04-13

    designed to allay 9 Leaf (accessed Oct 24, 2014). 10 Ankit Panda , “What to Expect if the U.S. Lifts...their animated populations. Despite the rhetoric, no ideology or nation is monolithic, thus opportunities exist to improve the U.S.-Sino...Joint Forces Quarterly 2 (2014): 76-80. Panda , Ankit. “What to Expect if the U.S. Lifts Its Vietnam Arms Embargo.” The Diplomat. September 29

  12. Simple Arm Muscle Model for Oil Palm Harvesting Process

    Directory of Open Access Journals (Sweden)

    Rahman Aliff

    2017-01-01

    Full Text Available Arm are essential in order to perform manual material handling work that normally involves lifting, handling, placing, push and pull, carrying and moving heavy loads. When these work elements are performed over prolonged periods repeatedly, it will expose workers arm to awkward posture and possible ergonomic risk factor. For example, work element that requires repetitions frequently may lead the arm to face physical stress and mental fatigue. The situation can be extremely risky if the worker task requires higher focus or time consumable. These issues are unavoidable in palm oil harvesting process since the workers are still using manual handling when harvesting the fresh fruit bunch (FFB. The worker using a chisel to harvest the young palms and a sickle mounted on a bamboo or aluminum pole to harvest taller palms. When perform this work element combining with heavy physical workload, it may lead to work-related muscle disorders (WSMDs. This study was conducted to identify the force reaction and inverse dynamic analysis during oil palm harvesting process using ergonomics software called Anybody Technology. Inverse dynamic analysis is a technique for figuring strengths and/or moments of power (torques taking into account the kinematics (movement of a body and the body’s inertial properties.

  13. A Bioinspired 10 DOF Wearable Powered Arm Exoskeleton for Rehabilitation

    Directory of Open Access Journals (Sweden)

    Soumya Kanti Manna

    2013-01-01

    Full Text Available The developed exoskeleton device (Exorn has ten degrees of freedom to control joints starting from shoulder griddle to wrist to provide better redundancy, portability, and flexibility to the human arm motion. A 3D conceptual model is being designed to make the system wearable by human arm. All the joints are simple revolute joints with desired motion limit. A Simulink model of the human arm is being developed with proper mass and length to determine proper torque required for actuating those joints. Forward kinematics of the whole system has been formulated for getting desired dexterous workspace. A proper and simple Graphical User Interface (GUI and the required embedded system have been designed for providing physiotherapy lessons to the patients. In the literature review it has been found that researchers have generally ignored the motion of shoulder griddle. Here we have implemented those motions in our design. It has also been found that people have taken elbow pronation and supination motion as a part of shoulder internal and external rotation though both motions are quite different. A predefined resolved motion rate control structure with independent joint control is used so that all movements can be controlled in a predefined way.

  14. Verification of models for ballistic movement time and endpoint variability.

    Science.gov (United States)

    Lin, Ray F; Drury, Colin G

    2013-01-01

    A hand control movement is composed of several ballistic movements. The time required in performing a ballistic movement and its endpoint variability are two important properties in developing movement models. The purpose of this study was to test potential models for predicting these two properties. Twelve participants conducted ballistic movements of specific amplitudes using a drawing tablet. The measured data of movement time and endpoint variability were then used to verify the models. This study was successful with Hoffmann and Gan's movement time model (Hoffmann, 1981; Gan and Hoffmann 1988) predicting more than 90.7% data variance for 84 individual measurements. A new theoretically developed ballistic movement variability model, proved to be better than Howarth, Beggs, and Bowden's (1971) model, predicting on average 84.8% of stopping-variable error and 88.3% of aiming-variable errors. These two validated models will help build solid theoretical movement models and evaluate input devices. This article provides better models for predicting end accuracy and movement time of ballistic movements that are desirable in rapid aiming tasks, such as keying in numbers on a smart phone. The models allow better design of aiming tasks, for example button sizes on mobile phones for different user populations.

  15. The Asteroid Redirect Mission (ARM)

    Science.gov (United States)

    Abell, Paul; Gates, Michele; Johnson, Lindley; Chodas, Paul; Mazanek, Dan; Reeves, David; Ticker, Ronald

    2016-07-01

    To achieve its long-term goal of sending humans to Mars, the National Aeronautics and Space Administration (NASA) plans to proceed in a series of incrementally more complex human spaceflight missions. Today, human flight experience extends only to Low-Earth Orbit (LEO), and should problems arise during a mission, the crew can return to Earth in a matter of minutes to hours. The next logical step for human spaceflight is to gain flight experience in the vicinity of the Moon. These cis-lunar missions provide a "proving ground" for the testing of systems and operations while still accommodating an emergency return path to the Earth that would last only several days. Cis-lunar mission experience will be essential for more ambitious human missions beyond the Earth-Moon system, which will require weeks, months, or even years of transit time. In addition, NASA has been given a Grand Challenge to find all asteroid threats to human populations and know what to do about them. Obtaining knowledge of asteroid physical properties combined with performing technology demonstrations for planetary defense provide much needed information to address the issue of future asteroid impacts on Earth. Hence the combined objectives of human exploration and planetary defense give a rationale for the Asteroid Re-direct Mission (ARM). Mission Description: NASA's ARM consists of two mission segments: 1) the Asteroid Redirect Robotic Mission (ARRM), the first robotic mission to visit a large (greater than ~100 m diameter) near-Earth asteroid (NEA), collect a multi-ton boulder from its surface along with regolith samples, demonstrate a planetary defense technique, and return the asteroidal material to a stable orbit around the Moon; and 2) the Asteroid Redirect Crewed Mission (ARCM), in which astronauts will take the Orion capsule to rendezvous and dock with the robotic vehicle, conduct multiple extravehicular activities to explore the boulder, and return to Earth with samples. NASA's proposed

  16. Biomechanical differences of arm swing countermovement jumps on sand and rigid surface performed by elite beach volleyball players.

    Science.gov (United States)

    Giatsis, George; Panoutsakopoulos, Vassilios; Kollias, Iraklis A

    2018-05-01

    The purpose of this study was to investigate the possible arm swing effect on the biomechanical parameters of vertical counter movement jump due to differences of the compliance of the take-off surface. Fifteen elite male beach-volleyball players (26.2 ± 5.9 years; 1.87 ± 0.05 m; 83.4 ± 6.0 kg; mean ± standard deviation, respectively) performed counter movement jumps on sand and on a rigid surface with and without an arm swing. Results showed significant (p volleyball.

  17. The French ecological movement

    International Nuclear Information System (INIS)

    Sansen, Bernard

    1977-01-01

    The analysis of the ecological Movement in France is presented: its organisation, its topics, its position with respect to the main political trends. The accent is put in particular on the antinuclear contestation [fr

  18. Movement and personality development

    Directory of Open Access Journals (Sweden)

    Aida M. Aylamazyan

    2017-06-01

    Full Text Available The paper discusses the role of the movement in the process of shaping the personality, its importance as a mechanism for personality development is considered. The issue of the movement has always occupied a central place in Russian psychology. However, subsequently the movement began to be considered primarily as an executive action in human life. The role of movement in personality development can vary depending on the level it occupies in the hierarchical structure of activity, and also on the type of movement, its character, and the way it is constructed. Under certain conditions, the movement can express the attitude of the subject to the surrounding world and people. Many foreign and Russian psychologists point to a special place of the postural tonic component of the motor movement, the posture in personal regulation. The posture reflects his/her personal attitudes, the system of relationships, and, above all, the emotional attitude or emotional assessment of the current situation, the interest in the actions performed. Mastering the tonic level of motor management is based on the emotional regulation, so the ability to regulate one’s own pose is an important stage in the personality development. Posture tonic regulation of motor movements in humans reveals a qualitatively different character than in animals, this being due to the person’s facing the task of mastering his’her posture, arbitrary retention of the body in one or another position. Maintaining a vertical posture requires constant activity at an arbitrary and involuntary level of mental regulation. Mastering the posture of an unstable equilibrium presupposes the emergence of the «I» and is the last stage of the development. The way a person solves the motor task of maintaining the vertical position of the body reflects his/her specific personal strategy or attitude.

  19. Rooted in Movement

    DEFF Research Database (Denmark)

    The result of the synergy between four doctoral projects and an advanced MA-level course on Bronze Age Europe, this integrated assemblage of articles represents a variety of different subjects united by a single theme: movement. Ranging from theoretical discussion of the various responses to and ...... period of European prehistory. In so doing, the text not only addresses transmission and reception, but also the conceptualization of mobility within a world which was literally Rooted in Movement....

  20. Model-based sensorimotor integration for multi-joint control: development of a virtual arm model.

    Science.gov (United States)

    Song, D; Lan, N; Loeb, G E; Gordon, J

    2008-06-01

    An integrated, sensorimotor virtual arm (VA) model has been developed and validated for simulation studies of control of human arm movements. Realistic anatomical features of shoulder, elbow and forearm joints were captured with a graphic modeling environment, SIMM. The model included 15 musculotendon elements acting at the shoulder, elbow and forearm. Muscle actions on joints were evaluated by SIMM generated moment arms that were matched to experimentally measured profiles. The Virtual Muscle (VM) model contained appropriate admixture of slow and fast twitch fibers with realistic physiological properties for force production. A realistic spindle model was embedded in each VM with inputs of fascicle length, gamma static (gamma(stat)) and dynamic (gamma(dyn)) controls and outputs of primary (I(a)) and secondary (II) afferents. A piecewise linear model of Golgi Tendon Organ (GTO) represented the ensemble sampling (I(b)) of the total muscle force at the tendon. All model components were integrated into a Simulink block using a special software tool. The complete VA model was validated with open-loop simulation at discrete hand positions within the full range of alpha and gamma drives to extrafusal and intrafusal muscle fibers. The model behaviors were consistent with a wide variety of physiological phenomena. Spindle afferents were effectively modulated by fusimotor drives and hand positions of the arm. These simulations validated the VA model as a computational tool for studying arm movement control. The VA model is available to researchers at website http://pt.usc.edu/cel .

  1. Octopus vulgaris uses visual information to determine the location of its arm.

    Science.gov (United States)

    Gutnick, Tamar; Byrne, Ruth A; Hochner, Binyamin; Kuba, Michael

    2011-03-22

    Octopuses are intelligent, soft-bodied animals with keen senses that perform reliably in a variety of visual and tactile learning tasks. However, researchers have found them disappointing in that they consistently fail in operant tasks that require them to combine central nervous system reward information with visual and peripheral knowledge of the location of their arms. Wells claimed that in order to filter and integrate an abundance of multisensory inputs that might inform the animal of the position of a single arm, octopuses would need an exceptional computing mechanism, and "There is no evidence that such a system exists in Octopus, or in any other soft bodied animal." Recent electrophysiological experiments, which found no clear somatotopic organization in the higher motor centers, support this claim. We developed a three-choice maze that required an octopus to use a single arm to reach a visually marked goal compartment. Using this operant task, we show for the first time that Octopus vulgaris is capable of guiding a single arm in a complex movement to a location. Thus, we claim that octopuses can combine peripheral arm location information with visual input to control goal-directed complex movements. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Post-Umbrella Movement: Localism and Radicalness of the Hong Kong Student Movement

    Directory of Open Access Journals (Sweden)

    Che-po Chan

    2016-08-01

    Full Text Available Hong Kong student movements before the Umbrella Movement showed a political outlook of voicing within norm of the establishment, using “peaceful, rational and non-violent” approaches, acknowledging the authorities of the Hong Kong Special Administrative Region (HKSAR and mainland Chinese governments and recognizing attachment to the motherland China. Today’s new emerging political outlook of the Hong Kong student movement has a profile of anti-establishment, using more assertive means and not excluding radical behaviour, distrust of the HKSAR and mainland authorities and assertion of radical localism. In the last two years, Hong Kong students have undergone a rapid change in their orientation, resulting in today’s outlook. This paper argues that the Umbrella Movement is the key for the turnaround and it testifies to the birth of a new social and political consciousness amongst Hong Kong students.

  3. The Propagation of Movement Variability in Time: A Methodological Approach for Discrete Movements with Multiple Degrees of Freedom

    Science.gov (United States)

    Krüger, Melanie; Straube, Andreas; Eggert, Thomas

    2017-01-01

    In recent years, theory-building in motor neuroscience and our understanding of the synergistic control of the redundant human motor system has significantly profited from the emergence of a range of different mathematical approaches to analyze the structure of movement variability. Approaches such as the Uncontrolled Manifold method or the Noise-Tolerance-Covariance decomposition method allow to detect and interpret changes in movement coordination due to e.g., learning, external task constraints or disease, by analyzing the structure of within-subject, inter-trial movement variability. Whereas, for cyclical movements (e.g., locomotion), mathematical approaches exist to investigate the propagation of movement variability in time (e.g., time series analysis), similar approaches are missing for discrete, goal-directed movements, such as reaching. Here, we propose canonical correlation analysis as a suitable method to analyze the propagation of within-subject variability across different time points during the execution of discrete movements. While similar analyses have already been applied for discrete movements with only one degree of freedom (DoF; e.g., Pearson's product-moment correlation), canonical correlation analysis allows to evaluate the coupling of inter-trial variability across different time points along the movement trajectory for multiple DoF-effector systems, such as the arm. The theoretical analysis is illustrated by empirical data from a study on reaching movements under normal and disturbed proprioception. The results show increased movement duration, decreased movement amplitude, as well as altered movement coordination under ischemia, which results in a reduced complexity of movement control. Movement endpoint variability is not increased under ischemia. This suggests that healthy adults are able to immediately and efficiently adjust the control of complex reaching movements to compensate for the loss of proprioceptive information. Further, it is

  4. Paraneoplastic autoimmune movement disorders.

    Science.gov (United States)

    Lim, Thien Thien

    2017-11-01

    To provide an overview of paraneoplastic autoimmune disorders presenting with various movement disorders. The spectrum of paraneoplastic autoimmune disorders has been expanding with the discovery of new antibodies against cell surface and intracellular antigens. Many of these paraneoplastic autoimmune disorders manifest as a form of movement disorder. With the discovery of new neuronal antibodies, an increasing number of idiopathic or neurodegenerative movement disorders are now being reclassified as immune-mediated movement disorders. These include anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis which may present with orolingual facial dyskinesia and stereotyped movements, CRMP-5 IgG presenting with chorea, anti-Yo paraneoplastic cerebellar degeneration presenting with ataxia, anti-VGKC complex (Caspr2 antibodies) neuromyotonia, opsoclonus-myoclonus-ataxia syndrome, and muscle rigidity and episodic spasms (amphiphysin, glutamic acid decarboxylase, glycine receptor, GABA(A)-receptor associated protein antibodies) in stiff-person syndrome. Movement disorders may be a presentation for paraneoplastic autoimmune disorders. Recognition of these disorders and their common phenomenology is important because it may lead to the discovery of an occult malignancy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Nuclear movement in fungi.

    Science.gov (United States)

    Xiang, Xin

    2017-12-11

    Nuclear movement within a cell occurs in a variety of eukaryotic organisms including yeasts and filamentous fungi. Fungal molecular genetic studies identified the minus-end-directed microtubule motor cytoplasmic dynein as a critical protein for nuclear movement or orientation of the mitotic spindle contained in the nucleus. Studies in the budding yeast first indicated that dynein anchored at the cortex via its anchoring protein Num1 exerts pulling force on an astral microtubule to orient the anaphase spindle across the mother-daughter axis before nuclear division. Prior to anaphase, myosin V interacts with the plus end of an astral microtubule via Kar9-Bim1/EB1 and pulls the plus end along the actin cables to move the nucleus/spindle close to the bud neck. In addition, pushing or pulling forces generated from cortex-linked polymerization or depolymerization of microtubules drive nuclear movements in yeasts and possibly also in filamentous fungi. In filamentous fungi, multiple nuclei within a hyphal segment undergo dynein-dependent back-and-forth movements and their positioning is also influenced by cytoplasmic streaming toward the hyphal tip. In addition, nuclear movement occurs at various stages of fungal development and fungal infection of plant tissues. This review discusses our current understanding on the mechanisms of nuclear movement in fungal organisms, the importance of nuclear positioning and the regulatory strategies that ensure the proper positioning of nucleus/spindle. Published by Elsevier Ltd.

  6. Antiglobalization movements and their critics

    DEFF Research Database (Denmark)

    Corry, Olaf

    2012-01-01

    inequity, organize transnationally, and maintain a critical stance toward significant aspects of the state system. For this reason, many supporters favor other terms such as alterglobalization movement, global justice movement , or simply the movement of movements . Critics accuse the movements...... of ideological incoherence, self-interested protectionism, and illiberal and undemocratic political methods, and point to Western liberal elite dominance within the movements. The debate has ...

  7. Self-directed therapy programmes for arm rehabilitation after stroke: a systematic review.

    Science.gov (United States)

    Da-Silva, Ruth H; Moore, Sarah A; Price, Christopher I

    2018-05-01

    To investigate the effectiveness of self-directed arm interventions in adult stroke survivors. A systematic review of Medline, EMBASE, CINAHL, SCOPUS and IEEE Xplore up to February 2018 was carried out. Studies of stroke arm interventions were included where more than 50% of the time spent in therapy was initiated and carried out by the participant. Quality of the evidence was assessed using the Cochrane risk of bias tool. A total of 40 studies ( n = 1172 participants) were included (19 randomized controlled trials (RCTs) and 21 before-after studies). Studies were grouped according to no technology or the main additional technology used (no technology n = 5; interactive gaming n = 6; electrical stimulation n = 11; constraint-induced movement therapy n = 6; robotic and dynamic orthotic devices n = 8; mirror therapy n = 1; telerehabilitation n = 2; wearable devices n = 1). A beneficial effect on arm function was found for self-directed interventions using constraint-induced movement therapy ( n = 105; standardized mean difference (SMD) 0.39, 95% confidence interval (CI) -0.00 to 0.78) and electrical stimulation ( n = 94; SMD 0.50, 95% CI 0.08-0.91). Constraint-induced movement therapy and therapy programmes without technology improved independence in activities of daily living. Sensitivity analysis demonstrated arm function benefit for patients >12 months poststroke ( n = 145; SMD 0.52, 95% CI 0.21-0.82) but not at 0-3, 3-6 or 6-12 months. Self-directed interventions can enhance arm recovery after stroke but the effect varies according to the approach used and timing. There were benefits identified from self-directed delivery of constraint-induced movement therapy, electrical stimulation and therapy programmes that increase practice without using additional technology.

  8. Generating human-like movements on an anthropomorphic robot using an interior point method

    Science.gov (United States)

    Costa e Silva, E.; Araújo, J. P.; Machado, D.; Costa, M. F.; Erlhagen, W.; Bicho, E.

    2013-10-01

    In previous work we have presented a model for generating human-like arm and hand movements on an anthropomorphic robot involved in human-robot collaboration tasks. This model was inspired by the Posture-Based Motion-Planning Model of human movements. Numerical results and simulations for reach-to-grasp movements with two different grip types have been presented previously. In this paper we extend our model in order to address the generation of more complex movement sequences which are challenged by scenarios cluttered with obstacles. The numerical results were obtained using the IPOPT solver, which was integrated in our MATLAB simulator of an anthropomorphic robot.

  9. Dual arm master controller development

    International Nuclear Information System (INIS)

    Kuban, D.P.; Perkins, G.S.

    1985-01-01

    The advanced servomanipulator (ASM) slave was designed with an anthropomorphic stance, gear/torque tube power drives, and modular construction. These features resulted in increased inertia, friction, and backlash relative to tape-driven manipulators. Studies were performed which addressed the human factors design and performance trade-offs associated with the corresponding master controller best suited for the ASM. The results of these studies, as well as the conceptual design of the dual arm master controller, are presented. This work was performed as part of the Consolidated Fuel Reprocessing Program at the Oak Ridge National Laboratory. 5 refs., 7 figs., 1 tab

  10. A dual visual-local feedback model of the vergence eye movement system

    NARCIS (Netherlands)

    Erkelens, C.J.

    2011-01-01

    Pure vergence movements are the eye movements that we make when we change our binocular fixation between targets differing in distance but not in direction relative to the head. Pure vergence is slow and controlled by visual feedback. Saccades are the rapid eye movements that we make between targets

  11. Arm-in-Arm Response Regulator Dimers Promote Intermolecular Signal Transduction

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Anna W.; Satyshur, Kenneth A.; Morales, Neydis Moreno; Forest, Katrina T. (UW)

    2016-02-01

    ABSTRACT

    Bacteriophytochrome photoreceptors (BphPs) and their cognate response regulators make up two-component signal transduction systems which direct bacteria to mount phenotypic responses to changes in environmental light quality. Most of these systems utilize single-domain response regulators to transduce signals through unknown pathways and mechanisms. Here we describe the photocycle and autophosphorylation kinetics of RtBphP1, a red light-regulated histidine kinase from the desert bacteriumRamlibacter tataouinensis. RtBphP1 undergoes red to far-red photoconversion with rapid thermal reversion to the dark state. RtBphP1 is autophosphorylated in the dark; this activity is inhibited under red light. The RtBphP1 cognate response regulator, theR. tataouinensisbacteriophytochrome response regulator (RtBRR), and a homolog, AtBRR fromAgrobacterium tumefaciens, crystallize unexpectedly as arm-in-arm dimers, reliant on a conserved hydrophobic motif, hFWAhL (where h is a hydrophobic M, V, L, or I residue). RtBRR and AtBRR dimerize distinctly from four structurally characterized phytochrome response regulators found in photosynthetic organisms and from all other receiver domain homodimers in the Protein Data Bank. A unique cacodylate-zinc-histidine tag metal organic framework yielded single-wavelength anomalous diffraction phases and may be of general interest. Examination of the effect of the BRR stoichiometry on signal transduction showed that phosphorylated RtBRR is accumulated more efficiently than the engineered monomeric RtBRR (RtBRRmon) in phosphotransfer reactions. Thus, we conclude that arm-in-arm dimers are a relevant signaling intermediate in this class of two-component regulatory systems.

  12. Three-dimensional neural net for learning visuomotor coordination of a robot arm.

    Science.gov (United States)

    Martinetz, T M; Ritter, H J; Schulten, K J

    1990-01-01

    An extension of T. Kohonen's (1982) self-organizing mapping algorithm together with an error-correction scheme based on the Widrow-Hoff learning rule is applied to develop a learning algorithm for the visuomotor coordination of a simulated robot arm. Learning occurs by a sequence of trial movements without the need for an external teacher. Using input signals from a pair of cameras, the closed robot arm system is able to reduce its positioning error to about 0.3% of the linear dimensions of its work space. This is achieved by choosing the connectivity of a three-dimensional lattice consisting of the units of the neural net.

  13. Jiu-jitsu in the Context of Armed Conflict: The Power of Nonviolent Resistance

    Directory of Open Access Journals (Sweden)

    María Belén Garrido

    2016-12-01

    Full Text Available This article explains how, through civil resistance, the community of Samaniego made the abuses of the armed actors in their territory backfire, a phenomenon described as “jiu-jitsu”. We examine the strategies used to generate this phenomenon during three main periods of civil resistance, focusing on two aspects: the organized structure of the civil resistance movement and the access to means that allow disseminating information about the situation. Based on interviews and on-site observation, we show how achieving a jiu-jitsu helped the community of Samaniego to be more autonomous from the armed actors.

  14. The application of accelerometers to measure movements of upper limbs: Pilot study

    Directory of Open Access Journals (Sweden)

    Patrik Kutilek

    2017-03-01

    Full Text Available Background: Even though inertial measurement units (IMU are already being used experimentally for evaluating movements of segment of the axial skeleton, no studies have been found which have used IMUs to measure the behavior of the segments of upper limbs during quiet stance. Objective: The objective is to design a suitable application of IMUs to measure movements of the upper extremities in Romberg's test and analyze spontaneous arm movements. Second aim is to identify possible discrepancies between the dominant and non-dominant arm movements. Methods: The dominant and non-dominant upper limb of each participant was identified. Then, the movements of both upper limbs were measured by the Xsens system equipped with MTx motion trackers during the quiet stance on a firm surface with eyes open (EO and eyes closed (EC. The measured data was used to calculate the medians and maximums of the superior-inferior, medio-lateral and anterior-posterior acceleration. Also, tremor intensity was calculated to quantitatively evaluate the measured data. Results: The comparison of values of maximal accelerations of the dominant and non-dominant arms showed significant difference between the arms during EC conditions. The comparison of values of median accelerations of the dominant and non-dominant arms showed significant differences between the acceleration of arms in medio-lateral direction during EO and EC conditions. In all cases, values of maximal and median accelerations and values of tremor intensity of the dominant limb strongly correlated with values on the non-dominant limb. Conclusions: Findings suggest possible usefulness of the designed application of IMUs and evaluation methods for their use in Romberg's test in clinical practice for evaluation of upper limb movements.

  15. Endoscopic endonasal transsphenoidal surgery using the iArmS operation support robot: initial experience in 43 patients.

    Science.gov (United States)

    Ogiwara, Toshihiro; Goto, Tetsuya; Nagm, Alhusain; Hongo, Kazuhiro

    2017-05-01

    Objective The intelligent arm-support system, iArmS, which follows the surgeon's arm and automatically fixes it at an adequate position, was developed as an operation support robot. iArmS was designed to support the surgeon's forearm to prevent hand trembling and to alleviate fatigue during surgery with a microscope. In this study, the authors report on application of this robotic device to endoscopic endonasal transsphenoidal surgery (ETSS) and evaluate their initial experiences. Methods The study population consisted of 43 patients: 29 with pituitary adenoma, 3 with meningioma, 3 with Rathke's cleft cyst, 2 with craniopharyngioma, 2 with chordoma, and 4 with other conditions. All patients underwent surgery via the endonasal transsphenoidal approach using a rigid endoscope. During the nasal and sphenoid phases, iArmS was used to support the surgeon's nondominant arm, which held the endoscope. The details of the iArmS and clinical results were collected. Results iArmS followed the surgeon's arm movement automatically. It reduced the surgeon's fatigue and stabilized the surgeon's hand during ETSS. Shaking of the video image decreased due to the steadying of the surgeon's scope-holding hand with iArmS. There were no complications related to use of the device. Conclusions The intelligent armrest, iArmS, seems to be safe and effective during ETSS. iArmS is helpful for improving the precision and safety not only for microscopic neurosurgery, but also for ETSS. Ongoing advances in robotics ensure the continued evolution of neurosurgery.

  16. Exact positioning of the robotic arm end effector

    Science.gov (United States)

    Korepanov, Valery; Dudkin, Fedir

    2016-07-01

    Orbital service becomes a new challenge of space exploration. The necessity to introduce it is connected first of all with an attractive opportunity to prolong the exploitation terms of expensive commercial satellites by, e.g., refilling of fuel or changing batteries. Other application area is a fight with permanently increasing amount of space litter - defunct satellites, burnt-out rocket stages, discarded trash and other debris. Now more than few tens of thousands orbiting objects larger than 5-10 cm (or about 1 million junks larger than 1 cm) are a huge problem for crucial and costly satellites and manned vehicles. For example, in 2014 the International Space Station had to change three times its orbit to avoid collision with space debris. So the development of the concepts and actions related to removal of space debris or non-operational satellites with use of robotic arm of a servicing satellite is very actual. Such a technology is also applicable for unmanned exploratory missions in solar system, for example for collecting a variety of samples from a celestial body surface. Naturally, the robotic arm movements should be controlled with great accuracy at influence of its non-rigidity, thermal and other factors. In these circumstances often the position of the arm end effector has to be controlled with high accuracy. The possibility of coordinate determination for the robotic arm end effector with use of a low frequency active electromagnetic system has been considered in the presented report. The proposed design of such a system consists of a small magnetic dipole source, which is mounted inside of the arm end effector and two or three 3-component magnetic field sensors mounted on a servicing satellite body. The data from this set of 3-component magnetic field sensors, which are fixed relatively to the satellite body, allows use of the mathematical approach for determination of position and orientation of the magnetic dipole source. The theoretical

  17. [Scenes in movement. Movement disorders on film].

    Science.gov (United States)

    Olivares Romero, J

    2010-03-01

    There are publications in which various neurological diseases are analysed on film. However, no references have been found on movement disorders in this medium. A total of 104 documents were collected and reviewed using the internet movie data base (IMDb). The majority were associated with dystonia, Parkinson's and tics, were American commercial productions, and the most common genre was drama. The cinema usually depicts old men with developed Parkinson's disease. However, motor complications only appear in 19% and non-motor symptoms in 14%. The image of dystonia is generally that of a young man, with disabling dystonia secondary to childhood cerebral palsy. Tics appear associated with Tourette's syndrome, with the excessive use of obscene expressions and with very few references to other important aspects of this syndrome, such as mood and behavioural changes. The majority of tremors portrayed on film are associated with Parkinsonism and are not pathological. Myoclonus appears anecdotically and is normally symptomatic. Parkinson's disease is the type of movement disorder that the cinema portrays with greater neurological honesty and in a more dignified manner.

  18. An online brain-machine interface using decoding of movement direction from the human electrocorticogram

    Science.gov (United States)

    Milekovic, Tomislav; Fischer, Jörg; Pistohl, Tobias; Ruescher, Johanna; Schulze-Bonhage, Andreas; Aertsen, Ad; Rickert, Jörn; Ball, Tonio; Mehring, Carsten

    2012-08-01

    A brain-machine interface (BMI) can be used to control movements of an artificial effector, e.g. movements of an arm prosthesis, by motor cortical signals that control the equivalent movements of the corresponding body part, e.g. arm movements. This approach has been successfully applied in monkeys and humans by accurately extracting parameters of movements from the spiking activity of multiple single neurons. We show that the same approach can be realized using brain activity measured directly from the surface of the human cortex using electrocorticography (ECoG). Five subjects, implanted with ECoG implants for the purpose of epilepsy assessment, took part in our study. Subjects used directionally dependent ECoG signals, recorded during active movements of a single arm, to control a computer cursor in one out of two directions. Significant BMI control was achieved in four out of five subjects with correct directional decoding in 69%-86% of the trials (75% on average). Our results demonstrate the feasibility of an online BMI using decoding of movement direction from human ECoG signals. Thus, to achieve such BMIs, ECoG signals might be used in conjunction with or as an alternative to intracortical neural signals.

  19. Admittance Control of a Multi-Finger Arm Based on Manipulability of Fingers

    Directory of Open Access Journals (Sweden)

    Takayuki Hori

    2011-09-01

    Full Text Available In the previous studies, admittance control and impedance control for a finger‐arm robot using the manipulability of the finger were studied and methods of realizing the controls have been proposed. In this study, two 3‐DOF fingers are attached to the end‐effector of a 6‐DOF arm to configure a multi‐finger arm robot. Based on the previous methods, the authors have proposed an admittance control for a multi‐finger arm robot using the manipulability of the fingers in this study. Algorithms of the averaging method and the mini‐max method were introduced to establish a manipulability criterion of the two fingers in order to generate a cooperative movement of the arm. Comparison of the admittance controls combined with the top search method and local optimization method for the multi‐finger arm robot was made and features of the control methods were also discussed. The stiffness control and damping control were experimentally evaluated to demonstrate the effectiveness of the proposed methods.

  20. Admittance Control of a Multi-Finger Arm Based on Manipulability of Fingers

    Directory of Open Access Journals (Sweden)

    Jian Huang

    2011-09-01

    Full Text Available In the previous studies, admittance control and impedance control for a finger-arm robot using the manipulability of the finger were studied and methods of realizing the controls have been proposed. In this study, two 3-DOF fingers are attached to the end-effector of a 6-DOF arm to configure a multi-finger arm robot. Based on the previous methods, the authors have proposed an admittance control for a multi-finger arm robot using the manipulability of the fingers in this study. Algorithms of the averaging method and the mini-max method were introduced to establish a manipulability criterion of the two fingers in order to generate a cooperative movement of the arm. Comparison of the admittance controls combined with the top search method and local optimization method for the multi-finger arm robot was made and features of the control methods were also discussed. The stiffness control and damping control were experimentally evaluated to demonstrate the effectiveness of the proposed methods.

  1. Soft robotic arm inspired by the octopus: I. From biological functions to artificial requirements

    International Nuclear Information System (INIS)

    Margheri, L; Laschi, C; Mazzolai, B

    2012-01-01

    Octopuses are molluscs that belong to the group Cephalopoda. They lack joints and rigid links, and as a result, their arms possess virtually limitless freedom of movement. These flexible appendages exhibit peculiar biomechanical features such as stiffness control, compliance, and high flexibility and dexterity. Studying the capabilities of the octopus arm is a complex task that presents a challenge for both biologists and roboticists, the latter of whom draw inspiration from the octopus in designing novel technologies within soft robotics. With this idea in mind, in this study, we used new, purposively developed methods of analysing the octopus arm in vivo to create new biologically inspired design concepts. Our measurements showed that the octopus arm can elongate by 70% in tandem with a 23% diameter reduction and exhibits an average pulling force of 40 N. The arm also exhibited a 20% mean shortening at a rate of 17.1 mm s −1 and a longitudinal stiffening rate as high as 2 N (mm s) −1 . Using histology and ultrasounds, we investigated the functional morphology of the internal tissues, including the sinusoidal arrangement of the nerve cord and the local insertion points of the longitudinal and transverse muscle fibres. The resulting information was used to create novel design principles and specifications that can in turn be used in developing a new soft robotic arm. (paper)

  2. Soft robotic arm inspired by the octopus: I. From biological functions to artificial requirements.

    Science.gov (United States)

    Margheri, L; Laschi, C; Mazzolai, B

    2012-06-01

    Octopuses are molluscs that belong to the group Cephalopoda. They lack joints and rigid links, and as a result, their arms possess virtually limitless freedom of movement. These flexible appendages exhibit peculiar biomechanical features such as stiffness control, compliance, and high flexibility and dexterity. Studying the capabilities of the octopus arm is a complex task that presents a challenge for both biologists and roboticists, the latter of whom draw inspiration from the octopus in designing novel technologies within soft robotics. With this idea in mind, in this study, we used new, purposively developed methods of analysing the octopus arm in vivo to create new biologically inspired design concepts. Our measurements showed that the octopus arm can elongate by 70% in tandem with a 23% diameter reduction and exhibits an average pulling force of 40 N. The arm also exhibited a 20% mean shortening at a rate of 17.1 mm s(-1) and a longitudinal stiffening rate as high as 2 N (mm s)(-1). Using histology and ultrasounds, we investigated the functional morphology of the internal tissues, including the sinusoidal arrangement of the nerve cord and the local insertion points of the longitudinal and transverse muscle fibres. The resulting information was used to create novel design principles and specifications that can in turn be used in developing a new soft robotic arm.

  3. Increasing cognitive load attenuates right arm swing in healthy human walking

    Science.gov (United States)

    Killeen, Tim; Easthope, Christopher S.; Filli, Linard; Lőrincz, Lilla; Schrafl-Altermatt, Miriam; Brugger, Peter; Linnebank, Michael; Curt, Armin; Zörner, Björn; Bolliger, Marc

    2017-01-01

    Human arm swing looks and feels highly automated, yet it is increasingly apparent that higher centres, including the cortex, are involved in many aspects of locomotor control. The addition of a cognitive task increases arm swing asymmetry during walking, but the characteristics and mechanism of this asymmetry are unclear. We hypothesized that this effect is lateralized and a Stroop word-colour naming task-primarily involving left hemisphere structures-would reduce right arm swing only. We recorded gait in 83 healthy subjects aged 18-80 walking normally on a treadmill and while performing a congruent and incongruent Stroop task. The primary measure of arm swing asymmetry-an index based on both three-dimensional wrist trajectories in which positive values indicate proportionally smaller movements on the right-increased significantly under dual-task conditions in those aged 40-59 and further still in the over-60s, driven by reduced right arm flexion. Right arm swing attenuation appears to be the norm in humans performing a locomotor-cognitive dual-task, confirming a prominent role of the brain in locomotor behaviour. Women under 60 are surprisingly resistant to this effect, revealing unexpected gender differences atop the hierarchical chain of locomotor control.

  4. Position Control Method For Pick And Place Robot Arm For Object Sorting System

    Directory of Open Access Journals (Sweden)

    Khin Moe Myint

    2015-08-01

    Full Text Available The more increase the number of industries in developing countries the more require labourers or workers in that. To reduce the cost of labour force and to increase the manufacturing capacity of industries the advanced robot arms are more needed. The aim of this journal is to eliminate the manual control for object sorting system.Robot arm design in this research uses two joints three links and servo motors to drive. Microcontroller is used to generate required PWM signal for servo motors. In this research the position control of robot arm was designed by using kinematic control methods. There are two types of kinematic control methods which are forward and reverse kinematic methods. In forward kinematic method the input parameters are the joint angles and link length of robot arm and then the output is the position at XYZ coordinate of tool or gripper. In inverse kinematic the input parameters are position at XYZ coordinate of gripper and the link length of robot arm and then the output parameters are the joint angles. So kinematic methods can explain the analytical description of the geometry motion of the manipulator with reference to a robot coordinate system fixed to a frame without consideration of the forces or the moments causing the movements. For sorting system Metal detector is used to detect the metal or non-metal. This position control of pick and place robot arm is fully tested and the result is obtained more precisely.

  5. Arming shoes of the fifteenth century

    OpenAIRE

    Volken Marquita

    2017-01-01

    Military footwear for the fifteenth century includes arming shoes worn under sabatons. Written sources suggest arming shoes and footwear used for fighting were ordinary shoes adapted for the purpose. Archaeological footwear was examined for signs of such modifications. Medieval shoe technology is presented, showing the range of footwear and its uses and gait biomechanics. Based on experiences from re-enactors wearing armours, medieval shoe styles are discussed for appropriateness as arming sh...

  6. Star distribution in the Orion spiral arm

    International Nuclear Information System (INIS)

    Basharina, T.S.; Pavlovskaya, E.D.; Filippova, A.A.

    1985-01-01

    The structure of the Orion spiral arm is studied by numerical experiments, assuming that in each direction considered the star distribution along the line of sight is a combination of two Gaussian laws. The corresponding parameters are evaluated for four Milky Way fields; the bimodal laws now fit the observations by the chi 2 criterion. In the Orion arm the line-of-sight star densities follow asymmetric curves, steeper at the outer edge of the arm

  7. Arms races between and within species.

    Science.gov (United States)

    Dawkins, R; Krebs, J R

    1979-09-21

    An adaptation in one lineage (e.g. predators) may change the selection pressure on another lineage (e.g. prey), giving rise to a counter-adaptation. If this occurs reciprocally, an unstable runaway escalation or 'arms race' may result. We discuss various factors which might give one side an advantage in an arms race. For example, a lineage under strong selection may out-evolve a weakly selected one (' the life-dinner principle'). We then classify arms races in two independent ways. They may be symmetric or asymmetric, and they may be interspecific or intraspecific. Our example of an asymmetric interspecific arms race is that between brood parasites and their hosts. The arms race concept may help to reduce the mystery of why cuckoo hosts are so good at detecting cuckoo eggs, but so bad at detecting cuckoo nestlings. The evolutionary contest between queen and worker ants over relative parental investment is a good example of an intraspecific asymmetric arms race. Such cases raise special problems because the participants share the same gene pool. Interspecific symmetric arms races are unlikely to be important, because competitors tend to diverge rather than escalate competitive adaptations. Intraspecific symmetric arms races, exemplified by adaptations for male-male competition, may underlie Cope's Rule and even the extinction of lineages. Finally we consider ways in which arms races can end. One lineage may drive the other to extinction; one may reach an optimum, thereby preventing the other from doing so; a particularly interesting possibility, exemplified by flower-bee coevolution, is that both sides may reach a mutual local optimum; lastly, arms races may have no stable and but may cycle continuously. We do not wish necessarily to suggest that all, or even most, evolutionary change results from arms races, but we do suggest that the arms race concept may help to resolve three long-standing questions in evolutionary theory.

  8. Preventing Interstate Armed Conflict : whose responsibility?

    OpenAIRE

    Otunba, Ganiyu

    2010-01-01

    This is a study of interstate armed conflict prevention. The concept of conflict, armed conflict and conflict prevention is defined and explained in order to be able to investigate if there is any single institution saddled with the responsibility of preventing interstate armed conflict and also to verify if adequate efforts are been put in this area which is of importance to mankind. The relationship between conflict prevention, conflict management and conflict resolution is also discussed s...

  9. Studying Social Movements

    DEFF Research Database (Denmark)

    Uldam, Julie; McCurdy, Patrick

    2013-01-01

    The research method of participant observation has long been used by scholars interested in the motivations, dynamics, tactics and strategies of social movements from a movement perspective. Despite participant observation being a common research method, there have been very few efforts to bring...... together this literature, which has often been spread across disciplines. This makes it difficult to identify the various challenges (and their interrelation) facing participant observers. Consequently, this article first reviews how participant observation roles have been conceptualised in general...... and then draws specific links to how the method has been used in the study of activism and social movements. In doing so, this article brings together key academic debates on participant observation, which have been considered separately, such as insider/outsider and overt/covert, but not previously been brought...

  10. Movement as utopia.

    Science.gov (United States)

    Couton, Philippe; López, José Julián

    2009-10-01

    Opposition to utopianism on ontological and political grounds has seemingly relegated it to a potentially dangerous form of antiquated idealism. This conclusion is based on a restrictive view of utopia as excessively ordered panoptic discursive constructions. This overlooks the fact that, from its inception, movement has been central to the utopian tradition. The power of utopianism indeed resides in its ability to instantiate the tension between movement and place that has marked social transformations in the modern era. This tension continues in contemporary discussions of movement-based social processes, particularly international migration and related identity formations, such as open borders transnationalism and cosmopolitanism. Understood as such, utopia remains an ongoing and powerful, albeit problematic instrument of social and political imagination.

  11. Atmospheric Radiation Measurement Climate Research (ARM)

    Data.gov (United States)

    Federal Laboratory Consortium — With heavily instrumented field sites around the globe, the ARM Climate Research Facility provides the world's most comprehensive outdoor laboratory and data archive...

  12. Current Migration Movements in Europe

    Directory of Open Access Journals (Sweden)

    Jelena Zlatković Winter

    2004-09-01

    Full Text Available After a brief historical review of migrations in Europe, the paper focuses on current migration trends and their consequences. At the end of the 1950s, Western Europe began to recruit labour from several Mediterranean countries – Italy, Spain, Portugal and former Yugoslavia, and later from Morocco, Algeria, Tunisia and Turkey. Some countries, such as France, Great Britain and the Netherlands, recruited also workers from their former colonies. In 1970 Germany had the highest absolute number of foreigners, followed by France, and then Switzerland and Belgium. The total number of immigrants in Western Europe was twelve million. During the 1970s mass recruitment of foreign workers was abandoned, and only the arrival of their family members was permitted, which led to family reunification in the countries of employment. Europe closed its borders, with the result that clandestine migration increased. The year 1989 was a turning point in the history of international migrations. The political changes in Central and Eastern Europe brought about mass migration to the West, which culminated in the so-called “mass movement of 1989–1990”. The arrival of ethnic Germans in Germany, migration inside and outside of the territory of the former Soviet Union, an increase in the number of asylum seekers and displaced persons, due to armed conflicts, are – according to the author – the main traits of current migration. The main part of the paper discusses the causes and effects of this mass wave, as well as trends in labour migration, which is still present. The second part of the paper, after presenting a typology of migrations, deals with the complex processes that brought about the formation of new communities and led to the phenomenon of new ethnic minorities and to corresponding migration policies in Western European countries that had to address these issues.

  13. Movement Without Boundaries

    Directory of Open Access Journals (Sweden)

    Jennifer Fortuna

    2017-10-01

    Full Text Available Johnson Simon, an artist based in West Palm Beach, FL, provided the cover art for the Fall 2017 edition of The Open Journal of Occupational Therapy (OJOT. “Dancing in Motion” is a 36” x 60” painting made from acrylic on canvas. Johnson always wanted to become a dancer. He was born with cerebral palsy, and therefore physical limitations make it difficult for Johnson to coordinate his body movements. Through use of vibrant colors and bold strokes, Johnson’s expressionist paintings evoke movement and motion. Occupational therapy helped Johnson discover his artistic abilities. Painting empowered him to move without limitations

  14. ICRESH-ARMS 2015 Conference

    CERN Document Server

    Ahmadi, Alireza; Verma, Ajit; Varde, Prabhakar

    2016-01-01

    Containing selected papers from the ICRESH-ARMS 2015 conference in Lulea, Sweden, collected by editors with years of experiences in Reliability and maintenance modeling, risk assessment, and asset management, this work maximizes reader insights into the current trends in Reliability, Availability, Maintainability and Safety (RAMS) and Risk Management. Featuring a comprehensive analysis of the significance of the role of RAMS and Risk Management in the decision making process during the various phases of design, operation, maintenance, asset management and productivity in Industrial domains, these proceedings discuss key issues and challenges in the operation, maintenance and risk management of complex engineering systems and will serve as a valuable resource for those in the field.

  15. Evolution of Gas Across Spiral Arms in the Whirlpool Galaxy

    Science.gov (United States)

    Louie, Melissa Nicole

    To investigate the dynamic evolution of gas across spiral arms, we conducted a detailed study of the gas and star formation along the spiral arms in the Whirlpool Galaxy, M51. This nearby, face-on spiral galaxy provides a unique laboratory to study the relationship between gas dynamics and star formation. The textbook picture of interstellar medium (ISM) evolution is rapidly changing. Molecular gas was once believed to form along spiral arms from the diffuse atomic gas in the inter-arm regions. Star formation occurs within giant molecular clouds during spiral arm passage. Lastly, the molecular gas is photo-dissociated back into atomic gas by massive stars on the downstream side of the spiral arm. Recent evidence, however, is revealing a new picture of the interstellar medium and the process of star formation. We seek development of a new picture by studying the development and evolution of molecular gas and the role of large scale galactic dynamics in organizing the interstellar medium. This thesis begins by presenting work measuring the geometrical offsets between interstellar gas and recent star formation. Interstellar gas is traced by atomic hydrogen and carbon monoxide (CO). Star formation is traced by ionized hydrogen recombination lines and infrared emission from dust warmed by young bright stars. Measuring these offsets can help determine the underlying large scale galactic dynamics. Along the spiral arms in M51, offsets between CO and the star formation tracers suggest that gas is flowing through the spiral arms, but the offsets do not show the expected signature of a single pattern speed and imply a more complicated pattern. This thesis also examines the intermediate stages of gas evolution, by studying a denser component of the ISM closer to which stars will form. Only a small percent of the bulk molecular gas will become dense enough to form stars. HCN and HCO+ probe densities ˜104 cm-3, where as the bulk gas is 500 cm-3. This thesis looks at HCN and

  16. Physiological modules for generating discrete and rhythmic movements: action identification by a dynamic recurrent neural network.

    Science.gov (United States)

    Bengoetxea, Ana; Leurs, Françoise; Hoellinger, Thomas; Cebolla, Ana M; Dan, Bernard; McIntyre, Joseph; Cheron, Guy

    2014-01-01

    In this study we employed a dynamic recurrent neural network (DRNN) in a novel fashion to reveal characteristics of control modules underlying the generation of muscle activations when drawing figures with the outstretched arm. We asked healthy human subjects to perform four different figure-eight movements in each of two workspaces (frontal plane and sagittal plane). We then trained a DRNN to predict the movement of the wrist from information in the EMG signals from seven different muscles. We trained different instances of the same network on a single movement direction, on all four movement directions in a single movement plane, or on all eight possible movement patterns and looked at the ability of the DRNN to generalize and predict movements for trials that were not included in the training set. Within a single movement plane, a DRNN trained on one movement direction was not able to predict movements of the hand for trials in the other three directions, but a DRNN trained simultaneously on all four movement directions could generalize across movement directions within the same plane. Similarly, the DRNN was able to reproduce the kinematics of the hand for both movement planes, but only if it was trained on examples performed in each one. As we will discuss, these results indicate that there are important dynamical constraints on the mapping of EMG to hand movement that depend on both the time sequence of the movement and on the anatomical constraints of the musculoskeletal system. In a second step, we injected EMG signals constructed from different synergies derived by the PCA in order to identify the mechanical significance of each of these components. From these results, one can surmise that discrete-rhythmic movements may be constructed from three different fundamental modules, one regulating the co-activation of all muscles over the time span of the movement and two others elliciting patterns of reciprocal activation operating in orthogonal directions.

  17. Rapid resolution of chronic shoulder pain classified as derangement using the McKenzie method: a case series

    Science.gov (United States)

    Aytona, Maria Corazon; Dudley, Karlene

    2013-01-01

    The McKenzie method, also known as Mechanical Diagnosis and Therapy (MDT), is primarily recognized as an evaluation and treatment method for the spine. However, McKenzie suggested that this method could also be applied to the extremities. Derangement is an MDT classification defined as an anatomical disturbance in the normal resting position of the joint, and McKenzie proposed that repeated movements could be applied to reduce internal joint displacement and rapidly reduce derangement symptoms. However, the current literature on MDT application to shoulder disorders is limited. Here, we present a case series involving four patients with chronic shoulder pain from a duration of 2–18 months classified as derangement and treated using MDT principles. Each patient underwent mechanical assessment and was treated with repeated movements based on their directional preference. All patients demonstrated rapid and clinically significant improvement in baseline measures and the disabilities of the arm, shoulder, and hand (QuickDASH) scores from an average of 38% at initial evaluation to 5% at discharge within 3–5 visits. Our findings suggest that MDT may be an effective treatment approach for shoulder pain. PMID:24421633

  18. A movement ecology paradigm for unifying organismal movement research.

    Science.gov (United States)

    Nathan, Ran; Getz, Wayne M; Revilla, Eloy; Holyoak, Marcel; Kadmon, Ronen; Saltz, David; Smouse, Peter E

    2008-12-09

    Movement of individual organisms is fundamental to life, quilting our planet in a rich tapestry of phenomena with diverse implications for ecosystems and humans. Movement research is both plentiful and insightful, and recent methodological advances facilitate obtaining a detailed view of individual movement. Yet, we lack a general unifying paradigm, derived from first principles, which can place movement studies within a common context and advance the development of a mature scientific discipline. This introductory article to the Movement Ecology Special Feature proposes a paradigm that integrates conceptual, theoretical, methodological, and empirical frameworks for studying movement of all organisms, from microbes to trees to elephants. We introduce a conceptual framework depicting the interplay among four basic mechanistic components of organismal movement: the internal state (why move?), motion (how to move?), and navigation (when and where to move?) capacities of the individual and the external factors affecting movement. We demonstrate how the proposed framework aids the study of various taxa and movement types; promotes the formulation of hypotheses about movement; and complements existing biomechanical, cognitive, random, and optimality paradigms of movement. The proposed framework integrates eclectic research on movement into a structured paradigm and aims at providing a basis for hypothesis generation and a vehicle facilitating the understanding of the causes, mechanisms, and spatiotemporal patterns of movement and their role in various ecological and evolutionary processes. "Now we must consider in general the common reason for moving with any movement whatever." (Aristotle, De Motu Animalium, 4th century B.C.).

  19. Rationality in Human Movement.

    Science.gov (United States)

    O'Brien, Megan K; Ahmed, Alaa A

    2016-01-01

    It long has been appreciated that humans behave irrationally in economic decisions under risk: they fail to objectively consider uncertainty, costs, and rewards and instead exhibit risk-seeking or risk-averse behavior. We hypothesize that poor estimates of motor variability (influenced by motor task) and distorted probability weighting (influenced by relevant emotional processes) contribute to characteristic irrationality in human movement decisions.

  20. The Matter of Movement

    DEFF Research Database (Denmark)

    Ayres, Phil

    2015-01-01

    This contribution concerns itself with the design and realisation of architectures that operate with material dynamics. It presents this concern as a counter to the consideration of movement in architecture as something conceptualised from the position of the observer. The contribution draws upon...

  1. Knowledge through movement

    DEFF Research Database (Denmark)

    Jensen, Søren Kjær; Moser, T.

    2003-01-01

    In: Children and adolescents in movement - perspectives and ideas. The Danish Ministry of Culture, pages 150 - 162. 2003 Short description: the article debunks a lot of the myths surrounding body and learning, and replace them with a vision about another kind of learning. The aim is to reintroduce...

  2. Mungiki as Youth Movement

    DEFF Research Database (Denmark)

    Rasmussen, Jacob

    2010-01-01

    Like many other African countries, Kenya has a large and growing youth population. Some of the youths are mobilized into militant and political networks; one of these is the Mungiki movement. The article explores Mungiki’s combination of politics, religion and Kikuyu traditions. Using the examples...

  3. The Evidence Movement

    DEFF Research Database (Denmark)

    Hansen, Hanne Foss; Rieper, Olaf

    2009-01-01

    The evidence movement and the idea of systematic reviews, defined as summaries of the results of already existing evaluation and research projects, have gained considerable support in recent years as many international as well as national evidence-producing organizations have been established...

  4. Managing Movement as Partnership

    Science.gov (United States)

    Kimbrell, Sinead

    2011-01-01

    The associate director of education at Hubbard Street Dance Chicago recounts her learning and teaching through managing the Movement as Partnership program. Included are detailed descriptions of encounters with teachers and students as they create choreography reflective of their inquiry into integrating dance and literacy arts curriculum in the…

  5. Music, Movement, and Poetry.

    Science.gov (United States)

    Carmichael, Karla D.

    This paper's premise is that music, movement, and poetry are unique and creative methods to be used by the counselor in working with both children and adults. Through these media, the counselor generates material for the counseling session that may not be available through more traditional "talk therapies." The choice of music as a counseling…

  6. Editorial: Body Movements

    Directory of Open Access Journals (Sweden)

    Carina Assuncao

    2018-01-01

    Full Text Available Today, the juxtaposition between physical bodies and the gameworld is ever more fluid. Virtual Reality headsets are available at game stores with more AAA games being created for the format. The release of the Nintendo Switch and its dynamic JoyCon controllers reintroduce haptic movement based controls.  Pokémon GO’s augmented reality took gamers outdoors and has encouraged the Harry Potter franchise to follow in its mobile footsteps. Each development encourages a step further into the digital world. At the same time, the movement of bodies always has political dimensions. We live in a world where walls seem like solutions to the movement of bodies, while the mere meeting of bodies elsewhere – for sex, marriage and other reasons – is still forbidden by many states’ rules. Games and game-like interfaces have shown the ability to bend those rules, and to sometimes project other worlds and rule systems over our world in order to make bodies move and meet. For this special issue on ‘Body Movements’, Press Start invited authors to focus on embodiment, body movements, political bodies, community bodies, virtual bodies, physical bodies, feminine, masculine, trans- bodies, agency or its lack, and anything else in between. The response to this invitation was variegated, and provocative, as outlined here.

  7. Morocco's February 20 Movement

    African Journals Online (AJOL)

    2018-02-20

    Feb 20, 2018 ... Council for the Development of Social Science Research in Africa, 2017 ... revolted several times, namely in big cities like Casablanca, Marrakech or .... region in order to take advantage of their experience and acquire a regional ..... Undoubtedly, with social networking, the dynamics of protest movements.

  8. [Architecture and movement].

    Science.gov (United States)

    Rivallan, Armel

    2012-01-01

    Leading an architectural project means accompanying the movement which it induces within the teams. Between questioning, uncertainty and fear, the organisational changes inherent to the new facility must be subject to constructive and ongoing exchanges. Ethics, safety and training are revised and the unit projects are sometimes modified.

  9. Effect of slow, small movement on the vibration-evoked kinesthetic illusion.

    Science.gov (United States)

    Cordo, P J; Gurfinkel, V S; Brumagne, S; Flores-Vieira, C

    2005-12-01

    The study reported in this paper investigated how vibration-evoked illusions of joint rotation are influenced by slow (0.3 degrees /s), small (2-4 degrees ) passive rotation of the joint. Normal human adults (n=15) matched the perceived position of the left ("reference") arm with the right ("matching") arm while vibration (50 pps, 0.5 mm) was applied for 30 s to the relaxed triceps brachii of the reference arm. Both arms were constrained to rotate horizontally at the elbow. Three experimental conditions were investigated: (1) vibration of the stationary reference arm, (2) slow, small passive extension or flexion of the reference arm during vibration, and (3) slow, small passive extension or flexion of the reference arm without vibration. Triceps brachii vibration at 50 pps induced an illusion of elbow flexion. The movement illusion began after several seconds, relatively fast to begin with and gradually slowing down to a stop. On average, triceps vibration produced illusory motion at an average latency of 6.3 s, amplitude of 9.7 degrees , velocity of 0.6 degrees /s, and duration of 16.4 s. During vibration, slow, small ( approximately 0.3 degrees /s, 1.3 degrees ) passive rotations of the joint dramatically enhanced, stopped, or reversed the direction of illusory movement, depending on the direction of the passive joint rotation. However, the subjects' perceptions of these passive elbow rotations were exaggerated: 2-3 times the size of the actual movement. In the absence of vibration, the subjects accurately reproduced these passive joint rotations. We discuss whether the exaggerated perception of slow, small movement during vibration is better explained by contributions of non muscle spindle Ia afferents or by changes in the mechanical transmission of vibration to the receptor.

  10. Automated processing of data on the use of motor vehicles in the Serbian Armed Forces

    Directory of Open Access Journals (Sweden)

    Nikola S. Osmokrović

    2012-10-01

    Full Text Available The main aim of introducing information technology into the armed forces is the automation of the management process. The management in movement and transport (M&T in our armed forces has been included in the process of automation from the beginning. For that reason, today we can speak about the automated processing of data on road traffic safety and on the use of motor vehicles. With regard to the overall development of the information system of the movement and transport service, the paper presents an information system of the M&T service for the processing of data on the use of motor vehicles. The main features, components and functions of the 'Vozila' application, which was specially developed for the automated processing of data on motor vehicle use, are explained in particular.

  11. Sensory-Feedback Exoskeletal Arm Controller

    Science.gov (United States)

    An, Bin; Massie, Thomas H.; Vayner, Vladimir

    2004-01-01

    An electromechanical exoskeletal arm apparatus has been designed for use in controlling a remote robotic manipulator arm. The apparatus, called a force-feedback exoskeleton arm master (F-EAM) is comfortable to wear and easy to don and doff. It provides control signals from the wearer s arm to a robot arm or a computer simulator (e.g., a virtual-reality system); it also provides force and torque feedback from sensors on the robot arm or from the computer simulator to the wearer s arm. The F-EAM enables the wearer to make the robot arm gently touch objects and finely manipulate them without exerting excessive forces. The F-EAM features a lightweight design in which the motors and gear heads that generate force and torque feedback are made smaller than they ordinarily would be: this is achieved by driving the motors to power levels greater than would ordinarily be used in order to obtain higher torques, and by providing active liquid cooling of the motors to prevent overheating at the high drive levels. The F-EAM (see figure) includes an assembly that resembles a backpack and is worn like a backpack, plus an exoskeletal arm mechanism. The FEAM has five degrees of freedom (DOFs) that correspond to those of the human arm: 1. The first DOF is that of the side-to-side rotation of the upper arm about the shoulder (rotation about axis 1). The reflected torque for this DOF is provided by motor 1 via drum 1 and a planar four-bar linkage. 2. The second DOF is that of the up-and-down rotation of the arm about the shoulder. The reflected torque for this DOF is provided by motor 2 via drum 2. 3. The third DOF is that of twisting of the upper arm about its longitudinal axis. This DOF is implemented in a cable remote-center mechanism (CRCM). The reflected torque for this DOF is provided by motor 3, which drives the upper-arm cuff and the mechanism below it. A bladder inflatable by gas or liquid is placed between the cuff and the wearer s upper arm to compensate for misalignment

  12. Whole arm manipulation planning based on feedback velocity fields and sampling-based techniques.

    Science.gov (United States)

    Talaei, B; Abdollahi, F; Talebi, H A; Omidi Karkani, E

    2013-09-01

    Changing the configuration of a cooperative whole arm manipulator is not easy while enclosing an object. This difficulty is mainly because of risk of jamming caused by kinematic constraints. To reduce this risk, this paper proposes a feedback manipulation planning algorithm that takes grasp kinematics into account. The idea is based on a vector field that imposes perturbation in object motion inducing directions when the movement is considerably along manipulator redundant directions. Obstacle avoidance problem is then considered by combining the algorithm with sampling-based techniques. As experimental results confirm, the proposed algorithm is effective in avoiding jamming as well as obstacles for a 6-DOF dual arm whole arm manipulator. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  13. Kinematics study and workspace analysis of an articulated robotic arm of a rpar

    International Nuclear Information System (INIS)

    Zeb, J.; Rashid, F.; Iqbal, N.

    2007-01-01

    An itinerant RPAR (Radiation Protection Assistant Robot) has been constructed to assist radiation workers in radiation area which are radiologically hazardous and beyond tile safe approach of radiation workers. The RPAR comprises of a cubicle tri- wheeled platform and a 4-DOF (Four Degree of Freedom) serial type articulated robotic arm. The movement of the platform is controlled by two differential wheeled driving systems. The Kinematics and Manipulator Jacobian of the end-effector (gripper) of the articulated robotic arm mounted on the RPAR were evaluated. The work space analyses of the articulated robotic arm have been carried out. The RPAR is helpful for surveillance of radiation zones, to pick and carry dropdown radioactive samples and sources, in routine radiological operations as well as during an emergency response to a radiological accident. The performance of the RPAR was found satisfactory. (author)

  14. A possible explanation for the origin of the magnetic fields in the galactic spiral arm

    International Nuclear Information System (INIS)

    Bagge, E.

    1975-04-01

    A theory for the movement of the interstellar gas under the influence of the gravitational field in the neighbourhood of the galactic arms is developped. If this gas bears electric charges of one sign (ωsub(e) approximately 3,000 electrons/gramm) a system of electric currents is produced by the relative velocity of the galactic gas and the spiral arms for which the streamlines are concentrated a little more to the galactic plane than above and below of it. By this way a large spaced magnetic field along the galactic arms is generated with opposite directions of the magnetic field vectors on the two sides of the galactic plane. (orig.) [de

  15. CCDC151 Mutations Cause Primary Ciliary Dyskinesia by Disruption of the Outer Dynein Arm Docking Complex Formation

    NARCIS (Netherlands)

    Hjeij, R.; Onoufriadis, A.; Watson, C.M.; Slagle, C.E.; Klena, N.T.; Dougherty, G.W.; Kurkowiak, M.; Loges, N.T.; Diggle, C.P.; Morante, N.F.; Gabriel, G.C.; Lemke, K.L.; Li, Y.; Pennekamp, P.; Menchen, T.; Konert, F.; Marthin, J.K.; Mans, D.A.; Letteboer, S.J.F.; Werner, C.; Burgoyne, T.; Westermann, C.; Rutman, A.; Carr, I.M.; O'Callaghan, C.; Moya, E.; Chung, E.M.; Consortium, U.K.; Sheridan, E.; Nielsen, K.G.; Roepman, R.; Bartscherer, K.; Burdine, R.D.; Lo, C.W.; Omran, H.; Mitchison, H.M.

    2014-01-01

    A diverse family of cytoskeletal dynein motors powers various cellular transport systems, including axonemal dyneins generating the force for ciliary and flagellar beating essential to movement of extracellular fluids and of cells through fluid. Multisubunit outer dynein arm (ODA) motor complexes,

  16. Multimodal movement prediction - towards an individual assistance of patients.

    Directory of Open Access Journals (Sweden)

    Elsa Andrea Kirchner

    Full Text Available Assistive devices, like exoskeletons or orthoses, often make use of physiological data that allow the detection or prediction of movement onset. Movement onset can be detected at the executing site, the skeletal muscles, as by means of electromyography. Movement intention can be detected by the analysis of brain activity, recorded by, e.g., electroencephalography, or in the behavior of the subject by, e.g., eye movement analysis. These different approaches can be used depending on the kind of neuromuscular disorder, state of therapy or assistive device. In this work we conducted experiments with healthy subjects while performing self-initiated and self-paced arm movements. While other studies showed that multimodal signal analysis can improve the performance of predictions, we show that a sensible combination of electroencephalographic and electromyographic data can potentially improve the adaptability of assistive technical devices with respect to the individual demands of, e.g., early and late stages in rehabilitation therapy. In earlier stages for patients with weak muscle or motor related brain activity it is important to achieve high positive detection rates to support self-initiated movements. To detect most movement intentions from electroencephalographic or electromyographic data motivates a patient and can enhance her/his progress in rehabilitation. In a later stage for patients with stronger muscle or brain activity, reliable movement prediction is more important to encourage patients to behave more accurately and to invest more effort in the task. Further, the false detection rate needs to be reduced. We propose that both types of physiological data can be used in an and combination, where both signals must be detected to drive a movement. By this approach the behavior of the patient during later therapy can be controlled better and false positive detections, which can be very annoying for patients who are further advanced in

  17. Stress analysis for robot arm version 2

    International Nuclear Information System (INIS)

    Anwar Abdul Rahman; Fikri, A.; Salleh, M. S.; Mohd Arif Hamzah; Azraf Azman; Rosli Darmawan; Mohd Rizal Mamat

    2010-01-01

    The design of a robot needs to be analyzed to ensure the specification and requirement by the user is full filled. Therefore, stress analysis has been performed on the robot arm version 2 after its complete fabrication. This paper discusses the result of the analysis and proposed measures to improve the future design of robot arm. (author)

  18. Homosexuality in the Dutch Armed Forces 2006

    NARCIS (Netherlands)

    Anna Adolfsen; Saskia Keuzenkamp; m.m.v. Linda Mans

    2006-01-01

    Original title: Uniform uit de kast. This study looks at the attitudes of defence personnel to homosexuality. How do members of the military view homosexual colleagues? Can gays and lesbians working in the armed forces be open about their sexual preferences? Do they regard the armed forces as

  19. Design of a biomimetic robotic octopus arm.

    Science.gov (United States)

    Laschi, C; Mazzolai, B; Mattoli, V; Cianchetti, M; Dario, P

    2009-03-01

    This paper reports the rationale and design of a robotic arm, as inspired by an octopus arm. The octopus arm shows peculiar features, such as the ability to bend in all directions, to produce fast elongations, and to vary its stiffness. The octopus achieves these unique motor skills, thanks to its peculiar muscular structure, named muscular hydrostat. Different muscles arranged on orthogonal planes generate an antagonistic action on each other in the muscular hydrostat, which does not change its volume during muscle contractions, and allow bending and elongation of the arm and stiffness variation. By drawing inspiration from natural skills of octopus, and by analysing the geometry and mechanics of the muscular structure of its arm, we propose the design of a robot arm consisting of an artificial muscular hydrostat structure, which is completely soft and compliant, but also able to stiffen. In this paper, we discuss the design criteria of the robotic arm and how this design and the special arrangement of its muscular structure may bring the building of a robotic arm into being, by showing the results obtained by mathematical models and prototypical mock-ups.

  20. TOWARDS UNIFORM RULES FOR ARMED CONFLICTS Pieter ...

    African Journals Online (AJOL)

    the two Additional Protocols that followed in 1977, divide armed conflict into two legal categories: ... Wounded, Sick and Shipwrecked Members of Armed Forces at Sea. Third Convention ... Nationalist China; ibid 116. ... 17 Pictet op cit 43; Junod, S 'Additional Protocol II: History and Scope' (1983) 33 The. American ...