Drawing from Memory: Hand-Eye Coordination at Multiple Scales

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Spivey, Michael J.

2013-01-01

Eyes move to gather visual information for the purpose of guiding behavior. This guidance takes the form of perceptual-motor interactions on short timescales for behaviors like locomotion and hand-eye coordination. More complex behaviors require perceptual-motor interactions on longer timescales mediated by memory, such as navigation, or designing and building artifacts. In the present study, the task of sketching images of natural scenes from memory was used to examine and compare perceptual-motor interactions on shorter and longer timescales. Eye and pen trajectories were found to be coordinated in time on shorter timescales during drawing, and also on longer timescales spanning study and drawing periods. The latter type of coordination was found by developing a purely spatial analysis that yielded measures of similarity between images, eye trajectories, and pen trajectories. These results challenge the notion that coordination only unfolds on short timescales. Rather, the task of drawing from memory evokes perceptual-motor encodings of visual images that preserve coarse-grained spatial information over relatively long timescales as well. PMID:23554894

The influence of speed and grade on wheelchair propulsion hand pattern.

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Slowik, Jonathan S; Requejo, Philip S; Mulroy, Sara J; Neptune, Richard R

2015-11-01

The hand pattern used during manual wheelchair propulsion (i.e., full-cycle hand path) can provide insight into an individual's propulsion technique. However, previous analyses of hand patterns have been limited by their focus on a single propulsion condition and reliance on subjective qualitative characterization methods. The purpose of this study was to develop a set of objective quantitative parameters to characterize hand patterns and determine the influence of propulsion speed and grade of incline on the patterns preferred by manual wheelchair users. Kinematic and kinetic data were collected from 170 experienced manual wheelchair users on an ergometer during three conditions: level propulsion at their self-selected speed, level propulsion at their fastest comfortable speed and graded propulsion (8%) at their level self-selected speed. Hand patterns were quantified using a set of objective parameters, and differences across conditions were identified. Increased propulsion speed resulted in a shift away from under-rim hand patterns. Increased grade of incline resulted in the hand remaining near the handrim throughout the cycle. Manual wheelchair users change their hand pattern based on task-specific constraints and goals. Further work is needed to investigate how differences between hand patterns influence upper extremity demand and potentially lead to the development of overuse injuries and pain. Copyright © 2015 Elsevier Ltd. All rights reserved.

Coordination in fast repetitive violin-bowing patterns.

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Schoonderwaldt, Erwin; Altenmüller, Eckart

2014-01-01

We present a study of coordination behavior in complex violin-bowing patterns involving simultaneous bow changes (reversal of bowing direction) and string crossings (changing from one string to another). Twenty-two violinists (8 advanced amateurs, 8 students with violin as major subject, and 6 elite professionals) participated in the experiment. We investigated the influence of a variety of performance conditions (specific bowing patterns, dynamic level, tempo, and transposition) and level of expertise on coordination behavior (a.o., relative phase and amplitude) and stability. It was found that the general coordination behavior was highly consistent, characterized by a systematic phase lead of bow inclination over bow velocity of about 15° (i.e., string crossings were consistently timed earlier than bow changes). Within similar conditions, a high individual consistency was found, whereas the inter-individual agreement was considerably less. Furthermore, systematic influences of performance conditions on coordination behavior and stability were found, which could be partly explained in terms of particular performance constraints. Concerning level of expertise, only subtle differences were found, the student and professional groups (higher level of expertise) showing a slightly higher stability than the amateur group (lower level of expertise). The general coordination behavior as observed in the current study showed a high agreement with perceptual preferences reported in an earlier study to similar bowing patterns, implying that complex bowing trajectories for an important part emerge from auditory-motor interaction.

Coordination in fast repetitive violin-bowing patterns.

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Erwin Schoonderwaldt

Full Text Available We present a study of coordination behavior in complex violin-bowing patterns involving simultaneous bow changes (reversal of bowing direction and string crossings (changing from one string to another. Twenty-two violinists (8 advanced amateurs, 8 students with violin as major subject, and 6 elite professionals participated in the experiment. We investigated the influence of a variety of performance conditions (specific bowing patterns, dynamic level, tempo, and transposition and level of expertise on coordination behavior (a.o., relative phase and amplitude and stability. It was found that the general coordination behavior was highly consistent, characterized by a systematic phase lead of bow inclination over bow velocity of about 15° (i.e., string crossings were consistently timed earlier than bow changes. Within similar conditions, a high individual consistency was found, whereas the inter-individual agreement was considerably less. Furthermore, systematic influences of performance conditions on coordination behavior and stability were found, which could be partly explained in terms of particular performance constraints. Concerning level of expertise, only subtle differences were found, the student and professional groups (higher level of expertise showing a slightly higher stability than the amateur group (lower level of expertise. The general coordination behavior as observed in the current study showed a high agreement with perceptual preferences reported in an earlier study to similar bowing patterns, implying that complex bowing trajectories for an important part emerge from auditory-motor interaction.

Learning robotic eye-arm-hand coordination from human demonstration: a coupled dynamical systems approach.

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Lukic, Luka; Santos-Victor, José; Billard, Aude

2014-04-01

We investigate the role of obstacle avoidance in visually guided reaching and grasping movements. We report on a human study in which subjects performed prehensile motion with obstacle avoidance where the position of the obstacle was systematically varied across trials. These experiments suggest that reaching with obstacle avoidance is organized in a sequential manner, where the obstacle acts as an intermediary target. Furthermore, we demonstrate that the notion of workspace travelled by the hand is embedded explicitly in a forward planning scheme, which is actively involved in detecting obstacles on the way when performing reaching. We find that the gaze proactively coordinates the pattern of eye-arm motion during obstacle avoidance. This study provides also a quantitative assessment of the coupling between the eye-arm-hand motion. We show that the coupling follows regular phase dependencies and is unaltered during obstacle avoidance. These observations provide a basis for the design of a computational model. Our controller extends the coupled dynamical systems framework and provides fast and synchronous control of the eyes, the arm and the hand within a single and compact framework, mimicking similar control system found in humans. We validate our model for visuomotor control of a humanoid robot.

Neural basis for hand muscle synergies in the primate spinal cord.

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Takei, Tomohiko; Confais, Joachim; Tomatsu, Saeka; Oya, Tomomichi; Seki, Kazuhiko

2017-08-08

Grasping is a highly complex movement that requires the coordination of multiple hand joints and muscles. Muscle synergies have been proposed to be the functional building blocks that coordinate such complex motor behaviors, but little is known about how they are implemented in the central nervous system. Here we demonstrate that premotor interneurons (PreM-INs) in the primate cervical spinal cord underlie the spatiotemporal patterns of hand muscle synergies during a voluntary grasping task. Using spike-triggered averaging of hand muscle activity, we found that the muscle fields of PreM-INs were not uniformly distributed across hand muscles but rather distributed as clusters corresponding to muscle synergies. Moreover, although individual PreM-INs have divergent activation patterns, the population activity of PreM-INs reflects the temporal activation of muscle synergies. These findings demonstrate that spinal PreM-INs underlie the muscle coordination required for voluntary hand movements in primates. Given the evolution of neural control of primate hand functions, we suggest that spinal premotor circuits provide the fundamental coordination of multiple joints and muscles upon which more fractionated control is achieved by superimposed, phylogenetically newer, pathways.

Optimizing pattern recognition-based control for partial-hand prosthesis application.

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Earley, Eric J; Adewuyi, Adenike A; Hargrove, Levi J

2014-01-01

Partial-hand amputees often retain good residual wrist motion, which is essential for functional activities involving use of the hand. Thus, a crucial design criterion for a myoelectric, partial-hand prosthesis control scheme is that it allows the user to retain residual wrist motion. Pattern recognition (PR) of electromyographic (EMG) signals is a well-studied method of controlling myoelectric prostheses. However, wrist motion degrades a PR system's ability to correctly predict hand-grasp patterns. We studied the effects of (1) window length and number of hand-grasps, (2) static and dynamic wrist motion, and (3) EMG muscle source on the ability of a PR-based control scheme to classify functional hand-grasp patterns. Our results show that training PR classifiers with both extrinsic and intrinsic muscle EMG yields a lower error rate than training with either group by itself (pgrasps available to the classifier significantly decrease classification error (pgrasp.

Improving operating room coordination: communication pattern assessment.

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Moss, Jacqueline; Xiao, Yan

2004-02-01

To capture communication patterns in operating room (OR) management to characterize the information needs of OR coordination. Technological applications can be used to change system processes to improve communication and information access, thereby decreasing errors and adverse events. The successful design of such applications relies on an understanding of communication patterns among healthcare professionals. Charge nurse communication was observed and documented at four OR suites at three tertiary hospitals. The data collection tool allowed rapid coding of communication patterns in terms of duration, mode, target person, and the purpose of each communication episode. Most (69.24%) of the 2074 communication episodes observed occurred face to face. Coordinating equipment was the most frequently occurring purpose of communication (38.7%) in all suites. The frequency of other purposes in decreasing order were coordinating patient preparedness (25.7%), staffing (18.8%), room assignment (10.7%), and scheduling and rescheduling surgery (6.2%). The results of this study suggest that automating aspects of preparing patients for surgery and surgical equipment management has the potential to reduce information exchange, decreasing interruptions to clinicians and diminishing the possibility of adverse events in the clinical setting.

Movement patterns of limb coordination in infant rolling.

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Kobayashi, Yoshio; Watanabe, Hama; Taga, Gentaro

2016-12-01

Infants must perform dynamic whole-body movements to initiate rolling, a key motor skill. However, little is known regarding limb coordination and postural control in infant rolling. To address this lack of knowledge, we examined movement patterns and limb coordination during rolling in younger infants (aged 5-7 months) that had just begun to roll and in older infants (aged 8-10 months) with greater rolling experience. Due to anticipated difficulty in obtaining measurements over the second half of the rolling sequence, we limited our analysis to the first half. Ipsilateral and contralateral limbs were identified on the basis of rolling direction and were classified as either a stationary limb used for postural stability or a moving limb used for controlled movement. We classified the observed movement patterns by identifying the number of stationary limbs and the serial order of combinational limb movement patterns. Notably, older infants performed more movement patterns that involved a lower number of stationary limbs than younger infants. Despite the wide range of possible movement patterns, a small group of basic patterns dominated in both age groups. Our results suggest that the fundamental structure of limb coordination during rolling in the early acquisition stages remains unchanged until at least 8-10 months of age. However, compared to younger infants, older infants exhibited a greater ability to select an effective rotational movement by positioning themselves with fewer stationary limbs and performing faster limb movements.

Review and Evaluation of Hand–Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces

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Ren G. Dong

2015-09-01

Full Text Available The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC system and an anatomically based biodynamic (BD system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study.

Review and Evaluation of Hand–Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces

Science.gov (United States)

Dong, Ren G.; Sinsel, Erik W.; Welcome, Daniel E.; Warren, Christopher; Xu, Xueyan S.; McDowell, Thomas W.; Wu, John Z.

2015-01-01

The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC) system and an anatomically based biodynamic (BD) system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study. PMID:26929824

Dynamical Coordination of Hand Intrinsic Muscles for Precision Grip in Diabetes Mellitus.

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Li, Ke; Wei, Na; Cheng, Mei; Hou, Xingguo; Song, Jun

2018-03-12

This study investigated the effects of diabetes mellitus (DM) on dynamical coordination of hand intrinsic muscles during precision grip. Precision grip was tested using a custom designed apparatus with stable and unstable loads, during which the surface electromyographic (sEMG) signals of the abductor pollicis brevis (APB) and first dorsal interosseous (FDI) were recorded simultaneously. Recurrence quantification analysis (RQA) was applied to quantify the dynamical structure of sEMG signals of the APB and FDI; and cross recurrence quantification analysis (CRQA) was used to assess the intermuscular coupling between the two intrinsic muscles. This study revealed that the DM altered the dynamical structure of muscle activation for the FDI and the dynamical intermuscular coordination between the APB and FDI during precision grip. A reinforced feedforward mechanism that compensates the loss of sensory feedbacks in DM may be responsible for the stronger intermuscular coupling between the APB and FDI muscles. Sensory deficits in DM remarkably decreased the capacity of online motor adjustment based on sensory feedback, rendering a lower adaptability to the uncertainty of environment. This study shed light on inherent dynamical properties underlying the intrinsic muscle activation and intermuscular coordination for precision grip and the effects of DM on hand sensorimotor function.

Movement constraints on interpersonal coordination and communication.

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Tolston, Michael T; Shockley, Kevin; Riley, Michael A; Richardson, Michael J

2014-10-01

The present study investigated how constraining movement affects interpersonal coordination and joint cognitive performance. Pairs of participants worked cooperatively to solve picture-puzzle tasks in which they conversed to identify differences between pictures in 3 degree-of-constraint conditions: both participants were free to move their hands (free-free; FF); both participants' hands were restrained (restrained-restrained; RR); and the hands of 1 participant were free while the hands of the other participant were restrained (free-restrained; FR). Eye tracking data were collected, and movement was measured at the waist, hand, and head. Data were analyzed using Cross-Recurrence Quantification Analysis (CRQ). Postural sway coordination, gaze coordination, and task performance were predicted to be highest in FF, followed by RR, and then by FR. Results showed the asymmetric FR condition generally exhibited lesser degrees of coordination than the symmetric Conditions FF and RR, and that the patterning of coordination in the symmetric conditions varied across the measured body segments. These results demonstrate that movement restraints affect not only interpersonal postural coordination, but also joint attention. Additionally, significant positive relationships were found between task performance and total amount of anterior-posterior movement measured at the head, hand and waist; number of utterances; and number of differences pairs found in the puzzles. These findings indicate a relationship between movement and task performance consistent with the hypotheses that both interpersonal coordination and cognitive performance are sensitive to local action constraints.

The relationship between temperamental traits and the level of performance of an eye-hand co-ordination task in jet pilots.

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Biernacki, Marcin; Tarnowski, Adam

2008-01-01

When assessing the psychological suitability for the profession of a pilot, it is important to consider personality traits and psychomotor abilities. Our study aimed at estimating the role of temperamental traits as components of pilots' personality in eye-hand co-ordination. The assumption was that differences in the escalation of the level of temperamental traits, as measured with the Formal Characteristic of Behaviour-Temperament Inventory (FCB-TI), will significantly influence eye-hand co-ordination. At the level of general scores, enhanced briskness proved to be the most important trait for eye-hand co-ordination. An analysis of partial scores additionally underlined the importance of sensory sensitivity, endurance and activity. The application of eye-hand co-ordination tasks, which involve energetic and temporal dimensions of performance, helped to disclose the role of biologically-based personality traits in psychomotor performance. The implication of these findings for selecting pilots is discussed.

Testing multiple coordination constraints with a novel bimanual visuomotor task.

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Helene M Sisti

Full Text Available The acquisition of a new bimanual skill depends on several motor coordination constraints. To date, coordination constraints have often been tested relatively independently of one another, particularly with respect to isofrequency and multifrequency rhythms. Here, we used a new paradigm to test the interaction of multiple coordination constraints. Coordination constraints that were tested included temporal complexity, directionality, muscle grouping, and hand dominance. Twenty-two healthy young adults performed a bimanual dial rotation task that required left and right hand coordination to track a moving target on a computer monitor. Two groups were compared, either with or without four days of practice with augmented visual feedback. Four directional patterns were tested such that both hands moved either rightward (clockwise, leftward (counterclockwise, inward or outward relative to each other. Seven frequency ratios (3∶1, 2∶1, 3∶2, 1∶1, 2∶3. 1∶2, 1∶3 between the left and right hand were introduced. As expected, isofrequency patterns (1∶1 were performed more successfully than multifrequency patterns (non 1∶1. In addition, performance was more accurate when participants were required to move faster with the dominant right hand (1∶3, 1∶2 and 2∶3 than with the non-dominant left hand (3∶1, 2∶1, 3∶2. Interestingly, performance deteriorated as the relative angular velocity between the two hands increased, regardless of whether the required frequency ratio was an integer or non-integer. This contrasted with previous finger tapping research where the integer ratios generally led to less error than the non-integer ratios. We suggest that this is due to the different movement topologies that are required of each paradigm. Overall, we found that this visuomotor task was useful for testing the interaction of multiple coordination constraints as well as the release from these constraints with practice in the presence of

Anchoring in a novel bimanual coordination pattern.

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Maslovat, Dana; Lam, Melanie Y; Brunke, Kirstin M; Chua, Romeo; Franks, Ian M

2009-02-01

Anchoring in cyclical movements has been defined as regions of reduced spatial or temporal variability [Beek, P. J. (1989). Juggling dynamics. PhD thesis. Amsterdam: Free University Press] that are typically found at movement reversal points. For in-phase and anti-phase movements, synchronizing reversal points with a metronome pulse has resulted in decreased anchor point variability and increased pattern stability [Byblow, W. D., Carson, R. G., & Goodman, D. (1994). Expressions of asymmetries and anchoring in bimanual coordination. Human Movement Science, 13, 3-28; Fink, P. W., Foo, P., Jirsa, V. K., & Kelso, J. A. S. (2000). Local and global stabilization of coordination by sensory information. Experimental Brain Research, 134, 9-20]. The present experiment examined anchoring during acquisition, retention, and transfer of a 90 degrees phase-offset continuous bimanual coordination pattern (whereby the right limb lags the left limb by one quarter cycle), involving horizontal flexion about the elbow. Three metronome synchronization strategies were imposed: participants either synchronized maximal flexion of the right arm (i.e., single metronome), both flexion and extension of the right arm (i.e., double metronome within-limb), or flexion of each arm (i.e., double metronome between-limb) to an auditory metronome. In contrast to simpler in-phase and anti-phase movements, synchronization of additional reversal points to the metronome did not reduce reversal point variability or increase pattern stability. Furthermore, practicing under different metronome synchronization strategies did not appear to have a significant effect on the rate of acquisition of the pattern.

Force-independent distribution of correlated neural inputs to hand muscles during three-digit grasping.

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Poston, Brach; Danna-Dos Santos, Alessander; Jesunathadas, Mark; Hamm, Thomas M; Santello, Marco

2010-08-01

The ability to modulate digit forces during grasping relies on the coordination of multiple hand muscles. Because many muscles innervate each digit, the CNS can potentially choose from a large number of muscle coordination patterns to generate a given digit force. Studies of single-digit force production tasks have revealed that the electromyographic (EMG) activity scales uniformly across all muscles as a function of digit force. However, the extent to which this finding applies to the coordination of forces across multiple digits is unknown. We addressed this question by asking subjects (n = 8) to exert isometric forces using a three-digit grip (thumb, index, and middle fingers) that allowed for the quantification of hand muscle coordination within and across digits as a function of grasp force (5, 20, 40, 60, and 80% maximal voluntary force). We recorded EMG from 12 muscles (6 extrinsic and 6 intrinsic) of the three digits. Hand muscle coordination patterns were quantified in the amplitude and frequency domains (EMG-EMG coherence). EMG amplitude scaled uniformly across all hand muscles as a function of grasp force (muscle x force interaction: P = 0.997; cosines of angle between muscle activation pattern vector pairs: 0.897-0.997). Similarly, EMG-EMG coherence was not significantly affected by force (P = 0.324). However, coherence was stronger across extrinsic than that across intrinsic muscle pairs (P = 0.0039). These findings indicate that the distribution of neural drive to multiple hand muscles is force independent and may reflect the anatomical properties or functional roles of hand muscle groups.

Development of an evaluation function for eye-hand coordination robotic therapy.

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Pernalete, N; Tang, F; Chang, S M; Cheng, F Y; Vetter, P; Stegemann, M; Grantner, J

2011-01-01

This paper is the continuation of a work presented at ICORR 07, in which we discussed the possibility of improving eye-hand coordination in children diagnosed with this problem, using a robotic mapping from a haptic user interface to a virtual environment. Our goal is to develop, implement and refine a system that will assess and improve the eye-hand coordination and grip strength in children diagnosed with poor graphomotor skills. A detailed analysis of patters (e.g., labyrinths, letters and angles) was conducted in order to select three very distinguishable levels of difficulty that could be included in the system, and which would yield the greatest benefit in terms of assessment of coordination and strength issues as well as in training. Support algorithms (position, force, velocity, inertia and viscosity) were also developed and incorporated into the tasks in order to introduce general computer assistance to the mapping of the user's movements to the computer screen without overriding the user's commands to the robotic device. In order to evaluate performance (given by %accuracy and time) of the executed tasks, a sophisticated evaluation function was designed based on image analysis and edge detection algorithms. This paper presents the development of the haptic tasks, the various assistance algorithms, the description of the evaluation function and the results of a study implemented at the Motor Development Clinic at Cal Poly Pomona. The results (Accuracy and Time) of this function are currently being used as inputs to an Intelligent Decision Support System (described in), which in turn, suggests the next task to be executed by the subject based on his/her performance. © 2011 IEEE

Causes And Pattern Of Unilateral Hand Injuries | Kaisha | East ...

African Journals Online (AJOL)

Objective: To assess the causes and pattern of hand injuries in patients with isolated unilateral acute hand injuries managed at the Kenyatta National Hospital (KNH). Design: A prospective cross-sectional descriptive study. Setting: Kenyatta National Hospital, Nairobi, Kenya, between May and August 2006. Subjects: All ...

Spatial pattern of Amazonian timber species using cartesian and spatial coordinates method

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Tiago Monteiro Condé

2016-06-01

Full Text Available Geographic information system (GIS applied to forest analysis permit the recognition and analysis of spatial patterns of species in two and three dimensional. The aim of this study to demonstrate the efficiency of cartesian and spatial coordinates method (MCCE, method of correcting UTM coordinates of trees location in accordance with the location of field or Cartesian (X ,Y, combined with natural neighbor index (ANND in recognition and analysis of spatial distribution patterns of four commercial timber species in forest management in Caracaraí, Roraima State, Brazil. Simulations were performed on 9 ha, divided into 100 plots of 100 m2 each. Collected data were DBH > 10 cm, commercial and total heights, cartesian coordinates (X,Y and spatial coordinates (UTM. Random spatial patterns were observed in Eschweilera bracteosa and Manilkara huberi. The dispersed and rare spatial patterns were observed in Dinizia excelsa and Cedrelinga cateniformis. MCCE proved to be an efficient method in the recognition and analysis of spatial patterns of native species from Amazon rain forest, as forest planning becomes easier by 2D and 3D simulations.

Shape-based hand recognition approach using the morphological pattern spectrum

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Ramirez-Cortes, Juan Manuel; Gomez-Gil, Pilar; Sanchez-Perez, Gabriel; Prieto-Castro, Cesar

2009-01-01

We propose the use of the morphological pattern spectrum, or pecstrum, as the base of a biometric shape-based hand recognition system. The system receives an image of the right hand of a subject in an unconstrained pose, which is captured with a commercial flatbed scanner. According to pecstrum property of invariance to translation and rotation, the system does not require the use of pegs for a fixed hand position, which simplifies the image acquisition process. This novel feature-extraction method is tested using a Euclidean distance classifier for identification and verification cases, obtaining 97% correct identification, and an equal error rate (EER) of 0.0285 (2.85%) for the verification mode. The obtained results indicate that the pattern spectrum represents a good feature-extraction alternative for low- and medium-level hand-shape-based biometric applications.

Patterns of shoulder muscle coordination vary between wheelchair propulsion techniques.

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Qi, Liping; Wakeling, James; Grange, Simon; Ferguson-Pell, Martin

2014-05-01

This study investigated changes in the coordination patterns of shoulder muscles and wheelchair kinetics with different propulsion techniques by comparing wheelchair users' self-selected propulsion patterns with a semicircular pattern adopted after instruction. Wheelchair kinetics data were recorded by Smart(Wheel) on an ergometer, while EMG activity of seven muscles was recorded with surface electrodes on 15 able-bodied inexperienced participants. The performance data in two sessions, first using a self-selected and then the learned semicircular pattern, were compared with a paired t-test. Muscle coordination patterns across seven muscles were analyzed by principal component analysis. The semicircular pattern was characterized by significantly lower push frequency, significantly longer push length, push duration and push distance (p propulsion technique, synergistic muscles were recruited in distinct phases and displayed a clearer separation between activities in the push phase and recovery phase muscles. An instruction session in semicircular propulsion technique is recommended for the initial use of a wheelchair after an injury.

Personal authentication through dorsal hand vein patterns

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Hsu, Chih-Bin; Hao, Shu-Sheng; Lee, Jen-Chun

2011-08-01

Biometric identification is an emerging technology that can solve security problems in our networked society. A reliable and robust personal verification approach using dorsal hand vein patterns is proposed in this paper. The characteristic of the approach needs less computational and memory requirements and has a higher recognition accuracy. In our work, the near-infrared charge-coupled device (CCD) camera is adopted as an input device for capturing dorsal hand vein images, it has the advantages of the low-cost and noncontact imaging. In the proposed approach, two finger-peaks are automatically selected as the datum points to define the region of interest (ROI) in the dorsal hand vein images. The modified two-directional two-dimensional principal component analysis, which performs an alternate two-dimensional PCA (2DPCA) in the column direction of images in the 2DPCA subspace, is proposed to exploit the correlation of vein features inside the ROI between images. The major advantage of the proposed method is that it requires fewer coefficients for efficient dorsal hand vein image representation and recognition. The experimental results on our large dorsal hand vein database show that the presented schema achieves promising performance (false reject rate: 0.97% and false acceptance rate: 0.05%) and is feasible for dorsal hand vein recognition.

An Approach for Pattern Recognition of EEG Applied in Prosthetic Hand Drive

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Xiao-Dong Zhang

2011-12-01

Full Text Available For controlling the prosthetic hand by only electroencephalogram (EEG, it has become the hot spot in robotics research to set up a direct communication and control channel between human brain and prosthetic hand. In this paper, the EEG signal is analyzed based on multi-complicated hand activities. And then, two methods of EEG pattern recognition are investigated, a neural prosthesis hand system driven by BCI is set up, which can complete four kinds of actions (arm’s free state, arm movement, hand crawl, hand open. Through several times of off-line and on-line experiments, the result shows that the neural prosthesis hand system driven by BCI is reasonable and feasible, the C-support vector classifiers-based method is better than BP neural network on the EEG pattern recognition for multi-complicated hand activities.

Design and characterization of the OpenWrist: A robotic wrist exoskeleton for coordinated hand-wrist rehabilitation.

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Pezent, Evan; Rose, Chad G; Deshpande, Ashish D; O'Malley, Marcia K

2017-07-01

Robotic devices have been clinically verified for use in long duration and high intensity rehabilitation needed for motor recovery after neurological injury. Targeted and coordinated hand and wrist therapy, often overlooked in rehabilitation robotics, is required to regain the ability to perform activities of daily living. To this end, a new coupled hand-wrist exoskeleton has been designed. This paper details the design of the wrist module and several human-related considerations made to maximize its potential as a coordinated hand-wrist device. The serial wrist mechanism has been engineered to facilitate donning and doffing for impaired subjects and to insure compatibility with the hand module in virtual and assisted grasping tasks. Several other practical requirements have also been addressed, including device ergonomics, clinician-friendliness, and ambidextrous reconfigurability. The wrist module's capabilities as a rehabilitation device are quantified experimentally in terms of functional workspace and dynamic properties. Specifically, the device possesses favorable performance in terms of range of motion, torque output, friction, and closed-loop position bandwidth when compared with existing devices. The presented wrist module's performance and operational considerations support its use in a wide range of future clinical investigations.

Effects of hand configuration on muscle force coordination, co-contraction and concomitant intermuscular coupling during maximal isometric flexion of the fingers.

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Charissou, Camille; Amarantini, David; Baurès, Robin; Berton, Eric; Vigouroux, Laurent

2017-11-01

The mechanisms governing the control of musculoskeletal redundancy remain to be fully understood. The hand is highly redundant, and shows different functional role of extensors according to its configuration for a same functional task of finger flexion. Through intermuscular coherence analysis combined with hand musculoskeletal modelling during maximal isometric hand contractions, our aim was to better understand the neural mechanisms underlying the control of muscle force coordination and agonist-antagonist co-contraction. Thirteen participants performed maximal isometric flexions of the fingers in two configurations: power grip (Power) and finger-pressing on a surface (Press). Hand kinematics and force/moment measurements were used as inputs in a musculoskeletal model of the hand to determine muscular tensions and co-contraction. EMG-EMG coherence analysis was performed between wrist and finger flexors and extensor muscle pairs in alpha, beta and gamma frequency bands. Concomitantly with tailored muscle force coordination and increased co-contraction between Press and Power (mean difference: 48.08%; p force coordination during hand contractions. Our results highlight the functional importance of intermuscular coupling as a mechanism contributing to the control of muscle force synergies and agonist-antagonist co-contraction.

Gambler's fallacy, hot hand belief, and the time of patterns

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Hongbin Wang

2010-04-01

Full Text Available The gambler's fallacy and the hot hand belief have been classified as two exemplars of human misperceptions of random sequential events. This article examines the times of pattern occurrences where a fair or biased coin is tossed repeatedly. We demonstrate that, due to different pattern composition, two different statistics (mean time and waiting time can arise from the same independent Bernoulli trials. When the coin is fair, the mean time is equal for all patterns of the same length but the waiting time is the longest for streak patterns. When the coin is biased, both mean time and waiting time change more rapidly with the probability of heads for a streak pattern than for a non-streak pattern. These facts might provide a new insight for understanding why people view streak patterns as rare and remarkable. The statistics of waiting time may not justify the prediction by the gambler's fallacy, but paying attention to streaks in the hot hand belief appears to be meaningful in detecting the changes in the underlying process.

Sequence for the Training of Eye-Hand Coordination Needed for the Organization of Handwriting Tasks

Science.gov (United States)

Trester, Mary Fran

1971-01-01

Suggested is a sequence of 11 class activities, progressing from gross to fine motor skills, to assist the development of skills required to perform handwriting tasks successfully, for use particularly with children who lack fine motor control and eye-hand coordination. (KW)

A process pattern language for coordinated software development

NARCIS (Netherlands)

Amrit, Chintan; ter Haar, René; Aydin, Mehmet N.; Hillegersberg, Jos Van

2007-01-01

In distributed and collocated teams we often find problems in the organizational process structures. Though process patterns have been around for many years, there has been little research in categorizing the different solutions to various problems dealing with coordination, for easy access by

Coordination patterns of shoulder muscles during level-ground and incline wheelchair propulsion.

Science.gov (United States)

Qi, Liping; Wakeling, James; Grange, Simon; Ferguson-Pell, Martin

2013-01-01

The aim of this study was to investigate how the coordination patterns of shoulder muscles change with level-ground and incline wheelchair propulsion. Wheelchair kinetics and electromyography (EMG) activity of seven muscles were recorded with surface electrodes for 15 nondisabled subjects during wheelchair propulsion on a stationary ergometer and wooden ramp (4 degree slope). Kinetic data were measured by a SmartWheel. The kinetics variables and the onset, cessation, and duration of EMG activity from seven muscles were compared with paired t-tests for two sessions. Muscle coordination patterns across seven muscles were analyzed by principal component analysis. Push forces on the push rim and the percentage of push phase in the cycle increased significantly during incline propulsion. Propulsion condition and posture affected muscle coordination patterns. During incline propulsion, there was more intense and longer EMG activity of push muscles in the push phase and less EMG activity of the recovery muscles, which corresponded with the increased kinetic data total force output and longer push phase in the incline condition. This work establishes a framework for developing a performance feedback system for wheelchair users to better coordinate their muscle patterning activity.

Virtual Control of Prosthetic Hand Based on Grasping Patterns and Estimated Force from Semg

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Zhu Gao-Ke

2016-01-01

Full Text Available Myoelectric prosthetic hands aim to serve upper limb amputees. The myoelectric control of the hand grasp action is a kind of real-time or online method. Thus it is of great necessity to carry on a study of online prosthetic hand electrical control. In this paper, the strategy of simultaneous EMG decoding of grasping patterns and grasping force was realized by controlling a virtual multi-degree-freedom prosthetic hand and a real one-degree-freedom prosthetic hand simultaneously. The former realized the grasping patterns from the recognition of the sEMG pattern. The other implemented the grasping force from sEMG force decoding. The results show that the control method is effective and feasible.

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

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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.

An Analysis of Intrinsic and Extrinsic Hand Muscle EMG for Improved Pattern Recognition Control.

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Adewuyi, Adenike A; Hargrove, Levi J; Kuiken, Todd A

2016-04-01

Pattern recognition control combined with surface electromyography (EMG) from the extrinsic hand muscles has shown great promise for control of multiple prosthetic functions for transradial amputees. There is, however, a need to adapt this control method when implemented for partial-hand amputees, who possess both a functional wrist and information-rich residual intrinsic hand muscles. We demonstrate that combining EMG data from both intrinsic and extrinsic hand muscles to classify hand grasps and finger motions allows up to 19 classes of hand grasps and individual finger motions to be decoded, with an accuracy of 96% for non-amputees and 85% for partial-hand amputees. We evaluated real-time pattern recognition control of three hand motions in seven different wrist positions. We found that a system trained with both intrinsic and extrinsic muscle EMG data, collected while statically and dynamically varying wrist position increased completion rates from 73% to 96% for partial-hand amputees and from 88% to 100% for non-amputees when compared to a system trained with only extrinsic muscle EMG data collected in a neutral wrist position. Our study shows that incorporating intrinsic muscle EMG data and wrist motion can significantly improve the robustness of pattern recognition control for application to partial-hand prosthetic control.

Using visual feedback distortion to alter coordinated pinching patterns for robotic rehabilitation

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Brewer Bambi R

2007-05-01

Full Text Available Abstract Background It is common for individuals with chronic disabilities to continue using the compensatory movement coordination due to entrenched habits, increased perception of task difficulty, or personality variables such as low self-efficacy or a fear of failure. Following our previous work using feedback distortion in a virtual rehabilitation environment to increase strength and range of motion, we address the use of visual feedback distortion environment to alter movement coordination patterns. Methods Fifty-one able-bodied subjects participated in the study. During the experiment, each subject learned to move their index finger and thumb in a particular target pattern while receiving visual feedback. Visual distortion was implemented as a magnification of the error between the thumb and/or index finger position and the desired position. The error reduction profile and the effect of distortion were analyzed by comparing the mean total absolute error and a normalized error that measured performance improvement for each subject as a proportion of the baseline error. Results The results of the study showed that (1 different coordination pattern could be trained with visual feedback and have the new pattern transferred to trials without visual feedback, (2 distorting individual finger at a time allowed different error reduction profile from the controls, and (3 overall learning was not sped up by distorting individual fingers. Conclusion It is important that robotic rehabilitation incorporates multi-limb or finger coordination tasks that are important for activities of daily life in the near future. This study marks the first investigation on multi-finger coordination tasks under visual feedback manipulation.

Effects of conventional neurological treatment and a virtual reality training program on eye-hand coordination in children with cerebral palsy.

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Shin, Ji-Won; Song, Gui-Bin; Hwangbo, Gak

2015-07-01

[Purpose] The purpose of the study was to evaluate the effects of conventional neurological treatment and a virtual reality training program on eye-hand coordination in children with cerebral palsy. [Subjects] Sixteen children (9 males, 7 females) with spastic diplegic cerebral palsy were recruited and randomly assigned to the conventional neurological physical therapy group (CG) and virtual reality training group (VRG). [Methods] Eight children in the control group performed 45 minutes of therapeutic exercise twice a week for eight weeks. In the experimental group, the other eight children performed 30 minutes of therapeutic exercise and 15 minutes of a training program using virtual reality twice a week during the experimental period. [Results] After eight weeks of the training program, there were significant differences in eye-hand coordination and visual motor speed in the comparison of the virtual reality training group with the conventional neurological physical therapy group. [Conclusion] We conclude that a well-designed training program using virtual reality can improve eye-hand coordination in children with cerebral palsy.

Hand eczema: Correlation of morphologic patterns, atopy, contact sensitization and disease severity

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Sanjeev Handa

2012-01-01

Full Text Available Background: Hand eczema is a common distressing condition aggravated by a number of endogenous and exogenous factors. Various morphological forms of hand eczema have been described, but categorization into one of them is not always possible. Aims: To study the morphological patterns of hand eczema, relationship of atopy with hand eczema, and the implications of contact sensitization with respect to severity and diagnosis of hand eczema. Methods: Hundred consecutive patients of hand eczema attending the contact dermatitis clinic of the institute were recruited over a two year period from 2004-05. Objective assessment was done using hand eczema severity index (HECSI and all the patients were patch tested using Indian standard series. Results: Unspecified type of hand eczema with no definite morphologic picture was seen in 62% followed by pompholyx in 14%. Hand eczema severity was not found to be statistically associated with age, sex, and atopic status of the patient. Positive patch test to one or more allergen was present in 65% of patients. The most common allergens were potassium dichromate (25%, fragrance mix (16%, nickel sulphate (14%, and PPD (13%. There was no significant correlation between patch test positivity and hand eczema severity or atopic status of the patient. Among the morphological patterns pompholyx was strongly associated with an atopic status (P=0.004. Conclusions: Hand eczema was seen twice more commonly in men. Atopic and non-atopic patients of hand eczema had no difference in the severity of disease. Contact sensitivity to different allergens did not correlate with increased eczema severity.

Real-Time Control of an Exoskeleton Hand Robot with Myoelectric Pattern Recognition.

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Lu, Zhiyuan; Chen, Xiang; Zhang, Xu; Tong, Kay-Yu; Zhou, Ping

2017-08-01

Robot-assisted training provides an effective approach to neurological injury rehabilitation. To meet the challenge of hand rehabilitation after neurological injuries, this study presents an advanced myoelectric pattern recognition scheme for real-time intention-driven control of a hand exoskeleton. The developed scheme detects and recognizes user's intention of six different hand motions using four channels of surface electromyography (EMG) signals acquired from the forearm and hand muscles, and then drives the exoskeleton to assist the user accomplish the intended motion. The system was tested with eight neurologically intact subjects and two individuals with spinal cord injury (SCI). The overall control accuracy was [Formula: see text] for the neurologically intact subjects and [Formula: see text] for the SCI subjects. The total lag of the system was approximately 250[Formula: see text]ms including data acquisition, transmission and processing. One SCI subject also participated in training sessions in his second and third visits. Both the control accuracy and efficiency tended to improve. These results show great potential for applying the advanced myoelectric pattern recognition control of the wearable robotic hand system toward improving hand function after neurological injuries.

Linear and nonlinear subspace analysis of hand movements during grasping.

Science.gov (United States)

Cui, Phil Hengjun; Visell, Yon

2014-01-01

This study investigated nonlinear patterns of coordination, or synergies, underlying whole-hand grasping kinematics. Prior research has shed considerable light on roles played by such coordinated degrees-of-freedom (DOF), illuminating how motor control is facilitated by structural and functional specializations in the brain, peripheral nervous system, and musculoskeletal system. However, existing analyses suppose that the patterns of coordination can be captured by means of linear analyses, as linear combinations of nominally independent DOF. In contrast, hand kinematics is itself highly nonlinear in nature. To address this discrepancy, we sought to to determine whether nonlinear synergies might serve to more accurately and efficiently explain human grasping kinematics than is possible with linear analyses. We analyzed motion capture data acquired from the hands of individuals as they grasped an array of common objects, using four of the most widely used linear and nonlinear dimensionality reduction algorithms. We compared the results using a recently developed algorithm-agnostic quality measure, which enabled us to assess the quality of the dimensional reductions that resulted by assessing the extent to which local neighborhood information in the data was preserved. Although qualitative inspection of this data suggested that nonlinear correlations between kinematic variables were present, we found that linear modeling, in the form of Principle Components Analysis, could perform better than any of the nonlinear techniques we applied.

An analysis of whorl patterns for determination of hand.

Science.gov (United States)

Kapoor, Neeti; Badiye, Ashish

2015-05-01

On crime scenes, whole set of the ten digit fingerprints are rarely found and usually chance prints in the form of single digit fingerprint are encountered. Determination of hand (Right or left) can be of vital importance to reduce the burden on the investigator and may thereby aid in fixation of absolute identity of the donor. In the present investigation, 500 randomly selected and bilateral rolled fingerprints of 250 healthy, consenting adult subjects of a central Indian (Marathi) population with whorl patterns were examined to determine the hand. It was found that by studying various parameters like; slope of apex ridges (towards right, left or absent), rotation of innermost ridges (either clockwise, anti-clockwise or absent), angle formed at both sides of core, position of the perpendicular bisector on the delta line (with respect to core), ridge tracing (outer, inner or meeting), higher ridge count, angle between deltas and core (at deltas), direction of the pattern (tilting/inclination) and distance between the deltas & the core; it is possible to successfully determine the hand of the print. Applying chi-square test, the results were found to be statistically significant at p < 0.01 levels. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Architecture for novel energy infrastructures. Multi-agent based coordination patterns

International Nuclear Information System (INIS)

Kamphuis, I.G.; Kok, J.K.; Warmer, C.J.; Hommelberg, M.P.F.

2009-01-01

Due to the increased proportion of small renewable energy sources in a distributed setting (DG-RES), active control of small distributed energy producing and consuming systems will play an important role in future electricity grids. These distributed energy resources have production patterns, which are either partially stochastic (e.g. wind, solar cells) or are coupled to the primary user process (e.g. co-generation of heat and electricity). Furthermore, on the demand-side, and increasingly on the electricity storage side, opportunities exist for actively serving stability applications in the grid by real-time supply/demand coordination. In the future, an information and communication layer for grid coordination could serve a portfolio of ICT-applications on timescales running from seconds to hours. To get a grip on these (r)evolutionary developments, possibly toppling the electricity grid, in this paper, architecture requirements for future high proportion DG-RES electricity grids are collected from a Power Electronics System point of view as well as from an ICT point of view using an inventory of business models in the power grid that focus on coordination of multiple small-scale DG-RES resources. Modeled from an ICT point-of-view, these give rise to architectures for applications that can successively be implemented in hardware and software as active components in the distribution grid. A number of possible grid control strategy coordination patterns (GCPs), which are defined in a generic, reusable manner, can be seen to emerge. GCPs, connected and intertwined to one another on several layers (physical, commercial) of the grid, together, can provide the framework for coordination in the overall intelligent grid. Bottom-up approaches of implementing coordination in future active grids appear to be the method of choice to use in implementing the GCPs. Software agents coordinating primary processes using market algorithms, as implemented in the Power

Contribution of Leg Muscle Explosive Power and Eye-Hand Coordination to The Accuracy Smash of Athletes in Volleyball Club of Universitas Islam Riau

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Mimi Yulianti

2017-11-01

Full Text Available The purpose of this study was to determine the contribution of leg muscle explosive power and eye-hand coordination. The type of research was correlational. The population in this study was all athletes who actively follow the training as many as 20 people and using total sampling technique. Thus the sample in this study amounted to 20 men athletes. The data were collected using the measurement test on the three variables: the leg muscle explosive power data was using vertical jump test, eyehand coordination was using ballwerfen und fangen test and smash accuracy was using smash accuracy test. The data were analyzed by product moment correlation and double correlation and then continued with contribution of the determinant formula. Based on data analysis found that there was contribution of leg muscle explosive power equal to 35,52%, eye-hand coordination equal to 20,79%, and both equal to 40,70% regarding to the accuracy smash of volleyball atletes of Universitas Islam Riau. It was concluded that there was contribution of leg muscle explosive power and eye-hand coordination to the smash accuracy of volleyball athlete of Universitas Islam Riau.

Digital fringe projection for hand surface coordinate variation analysis caused by osteoarthritis

Science.gov (United States)

Nor Haimi, Wan Mokhdzani Wan; Hau Tan, Cheek; Retnasamy, Vithyacharan; Vairavan, Rajendaran; Sauli, Zaliman; Roshidah Yusof, Nor; Hambali, Nor Azura Malini Ahmad; Aziz, Muhammad Hafiz Ab; Bakhit, Ahmad Syahir Ahmad

2017-11-01

Hand osteoarthritis is one of the most common forms of arthritis which impact millions of people worldwide. The disabling problem occurs when the protective cartilage on the boundaries of bones wear off over time. Currently, in order to identify hand osteoarthritis, special instruments namely X-ray scanning and MRI are used for the detection but it also has its limitations such as radiation exposure and can be quite costly. In this work, an optical metrology system based on digital fringe projection which comprises of an LCD projector, CCD camera and a personal computer has been developed to anticipate abnormal growth or deformation on the joints of the hand which are common symptoms of osteoarthritis. The main concept of this optical metrology system is to apply structured light as imaging source for surface change detection. The imaging source utilizes fringe patterns generated by C++ programming and is shifted by 3 phase shifts based on the 3 steps 2 shifts method. Phase wrapping technique and analysis were applied in order to detect the deformation of live subjects. The result has demonstrated a successful method of hand deformation detection based on the pixel tracking differences of a normal and deformed state.

Switching among graphic patterns is governed by oscillatory coordination dynamics: Implications for understanding handwriting.

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Pier-Giorgio eZanone

2013-09-01

Full Text Available Revisiting an original idea by Hollerbach (1981, previous work has established that the production of graphic shapes, assumed to be the blueprint for handwriting, is governed by the dynamics of orthogonal non-linear coupled oscillators. Such dynamics determines few stable coordination patterns, giving rise to a limited set of preferred graphic shapes, namely, four lines and four ellipsoids independent of orientation. The present study investigates the rules of switching among such graphic coordination patterns. Seven participants were required to voluntarily switch within twelve pairs of shapes presented on a graphic tablet. In line with previous theoretical and experimental work on bimanual coordination, results corroborated our hypothesis that the relative stability of the produced coordination patterns determines the time needed for switching: the transition to a more stable pattern was shorter, and inversely. Moreover, switching between patterns with the same orientation but different eccentricities was faster than with a change in orientation. Nonetheless, the switching time covaried strictly with the change in relative phase effected by the transition between two shapes, whether this implied a change in eccentricity or in orientation. These findings suggest a new operational definition of what the (motor units or strokes of handwriting are and shed a novel light on how co-articulation and recruitment of degrees of freedom may occur in graphic skills. They also yield some leads for understanding the acquisition and the neural underpinnings of handwriting.

The Virtual Teacher (VT) Paradigm: Learning New Patterns of Interpersonal Coordination Using the Human Dynamic Clamp.

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Kostrubiec, Viviane; Dumas, Guillaume; Zanone, Pier-Giorgio; Kelso, J A Scott

2015-01-01

The Virtual Teacher paradigm, a version of the Human Dynamic Clamp (HDC), is introduced into studies of learning patterns of inter-personal coordination. Combining mathematical modeling and experimentation, we investigate how the HDC may be used as a Virtual Teacher (VT) to help humans co-produce and internalize new inter-personal coordination pattern(s). Human learners produced rhythmic finger movements whilst observing a computer-driven avatar, animated by dynamic equations stemming from the well-established Haken-Kelso-Bunz (1985) and Schöner-Kelso (1988) models of coordination. We demonstrate that the VT is successful in shifting the pattern co-produced by the VT-human system toward any value (Experiment 1) and that the VT can help humans learn unstable relative phasing patterns (Experiment 2). Using transfer entropy, we find that information flow from one partner to the other increases when VT-human coordination loses stability. This suggests that variable joint performance may actually facilitate interaction, and in the long run learning. VT appears to be a promising tool for exploring basic learning processes involved in social interaction, unraveling the dynamics of information flow between interacting partners, and providing possible rehabilitation opportunities.

Use of a machine learning algorithm to classify expertise: analysis of hand motion patterns during a simulated surgical task.

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Watson, Robert A

2014-08-01

To test the hypothesis that machine learning algorithms increase the predictive power to classify surgical expertise using surgeons' hand motion patterns. In 2012 at the University of North Carolina at Chapel Hill, 14 surgical attendings and 10 first- and second-year surgical residents each performed two bench model venous anastomoses. During the simulated tasks, the participants wore an inertial measurement unit on the dorsum of their dominant (right) hand to capture their hand motion patterns. The pattern from each bench model task performed was preprocessed into a symbolic time series and labeled as expert (attending) or novice (resident). The labeled hand motion patterns were processed and used to train a Support Vector Machine (SVM) classification algorithm. The trained algorithm was then tested for discriminative/predictive power against unlabeled (blinded) hand motion patterns from tasks not used in the training. The Lempel-Ziv (LZ) complexity metric was also measured from each hand motion pattern, with an optimal threshold calculated to separately classify the patterns. The LZ metric classified unlabeled (blinded) hand motion patterns into expert and novice groups with an accuracy of 70% (sensitivity 64%, specificity 80%). The SVM algorithm had an accuracy of 83% (sensitivity 86%, specificity 80%). The results confirmed the hypothesis. The SVM algorithm increased the predictive power to classify blinded surgical hand motion patterns into expert versus novice groups. With further development, the system used in this study could become a viable tool for low-cost, objective assessment of procedural proficiency in a competency-based curriculum.

Use of Design Patterns According to Hand Dominance in a Mobile User Interface

Science.gov (United States)

Al-Samarraie, Hosam; Ahmad, Yusof

2016-01-01

User interface (UI) design patterns for mobile applications provide a solution to design problems and can improve the usage experience for users. However, there is a lack of research categorizing the uses of design patterns according to users' hand dominance in a learning-based mobile UI. We classified the main design patterns for mobile…

Patterns of horse-rider coordination during endurance race: a dynamical system approach.

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Sylvain Viry

Full Text Available In riding, most biomechanical studies have focused on the description of the horse locomotion in unridden condition. In this study, we draw the prospect of how the basic principles established in inter-personal coordination by the theory of Coordination Dynamics may provide a conceptual and methodological framework for understanding the horse-rider coupling. The recent development of mobile technologies allows combined horse and rider recordings during long lasting natural events such as endurance races. Six international horse-rider dyads were thus recorded during a 120 km race by using two tri-axial accelerometers placed on the horses and riders, respectively. The analysis concentrated on their combined vertical displacements. The obtained shapes and angles of Lissajous plots together with values of relative phase between horse and rider displacements at lower reversal point allowed us to characterize four coordination patterns, reflecting the use of two riding techniques per horse's gait (trot and canter. The present study shows that the concepts, methods and tools of self-organizing dynamic system approach offer new directions for understanding horse-rider coordination. The identification of the horse-rider coupling patterns constitutes a firm basis to further study the coalition of multiple constraints that determine their emergence and their dynamics in endurance race.

Left Hand Thumb Imprint Patterns Among Medical Students.

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Khan, Omair; Haroon, Muhammad Zeeshan; Rashid, Muhammad Adnan; Khan, Muhammad Naseem; Khan, Delawar

2017-01-01

Finger printing is an absolute method of identification. Recovery of finger prints from a crime scene is an important method of Forensic identification. Human finger prints are detailed, unique, difficult to alter, easily classifiable and durable over life making them stable and long-term tool of human identification. This cross-sectional study was conducted on 95,3rd year MBBS students of Ayub Medical College Abbottabad from December 2014 to August 2015 to establish the frequency of left hand thumb imprints by rolling and plain method. Study shows Loops among most common finger print pattern in 55 (58%) students out of 95, followed by whorls 33 (35%), arches 5 (5%) and composite 2 (2%). It is thus concluded that most common finger print pattern is loops followed by whorls, arches and composite.

Motor coordination uses external spatial coordinates independent of developmental vision.

Science.gov (United States)

Heed, Tobias; Röder, Brigitte

2014-07-01

The constraints that guide bimanual movement coordination are informative about the processing principles underlying movement planning in humans. For example, symmetry relative to the body midline benefits finger and hand movements independent of hand posture. This symmetry constraint has been interpreted to indicate that movement coordination is guided by a perceptual code. Although it has been assumed implicitly that the perceptual system at the heart of this constraint is vision, this relationship has not been tested. Here, congenitally blind and sighted participants made symmetrical and non-symmetrical (that is, parallel) bimanual tapping and finger oscillation movements. For both groups, symmetrical movements were executed more correctly than parallel movements, independent of anatomical constraints like finger homology and hand posture. For the blind, the reliance on external spatial factors in movement coordination stands in stark contrast to their use of an anatomical reference frame in perceptual processing. Thus, the externally coded symmetry constraint evident in bimanual coordination can develop in the absence of the visual system, suggesting that the visual system is not critical for the establishment of an external-spatial reference frame in movement coordination. Copyright © 2014 Elsevier B.V. All rights reserved.

Exploration of Hand Grasp Patterns Elicitable Through Non-Invasive Proximal Nerve Stimulation

OpenAIRE

Shin, Henry; Watkins, Zach; Hu, Xiaogang

2017-01-01

Various neurological conditions, such as stroke or spinal cord injury, result in an impaired control of the hand. One method of restoring this impairment is through functional electrical stimulation (FES). However, traditional FES techniques often lead to quick fatigue and unnatural ballistic movements. In this study, we sought to explore the capabilities of a non-invasive proximal nerve stimulation technique in eliciting various hand grasp patterns. The ulnar and median nerves proximal to th...

Prevalence and pattern of radiographic hand osteoarthritis and association with pain and disability (the Rotterdam study)

NARCIS (Netherlands)

S. Dahaghin; S.M. Bierma-Zeinstra (Sita); A.Z. Ginai (Abida); H.A.P. Pols (Huib); J.M.W. Hazes (Mieke); B.W. Koes (Bart)

2005-01-01

textabstractOBJECTIVE: To investigate the prevalence and pattern of radiographic osteoarthritis (ROA) of the hand joints and its association with self reported hand pain and disability. METHODS: Baseline data on a population based study (age >/=55 years) were used (n = 3906). Hand

In a demanding task, three-handed manipulation is preferred to two-handed manipulation.

Science.gov (United States)

Abdi, Elahe; Burdet, Etienne; Bouri, Mohamed; Himidan, Sharifa; Bleuler, Hannes

2016-02-25

Equipped with a third hand under their direct control, surgeons may be able to perform certain surgical interventions alone; this would reduce the need for a human assistant and related coordination difficulties. However, does human performance improve with three hands compared to two hands? To evaluate this possibility, we carried out a behavioural study on the performance of naive adults catching objects with three virtual hands controlled by their two hands and right foot. The subjects could successfully control the virtual hands in a few trials. With this control strategy, the workspace of the hands was inversely correlated with the task velocity. The comparison of performance between the three and two hands control revealed no significant difference of success in catching falling objects and in average effort during the tasks. Subjects preferred the three handed control strategy, found it easier, with less physical and mental burden. Although the coordination of the foot with the natural hands increased trial after trial, about two minutes of practice was not sufficient to develop a sense of ownership towards the third arm.

Patterns of radiographic changes in hands and feet of rheumatoid arthritis in Saudi Arabia

International Nuclear Information System (INIS)

Al-Arfaj, Abdurhman S.; Al-Boukai, Ahmad A.

2005-01-01

The aim of the study was to characterize the pattern of radiographic changes in the hands and feet of rheumatoid arthritis in Saudi patients. The radiographs of hands and feet of rheumatoid arthritis patients attending rheumatology outpatient clinics of King Khalid University Hospital in Riyadh, Kingdom of Saudi Arabia, over the period extending from March to June 2001, were examined and reported for the presence of osteopenia, joint space narrowing, and erosions. Fifty-six rheumatoid arthritis patients were studied. Their mean age was 50 + 1.9 years, and mean disease duration was 9.07 + 0.84 years. Generalized osteopenia was seen in 16/56 (29%) and periarticular osteopenia in 38/56 (68%). Joint space narrowing was present in 9/56 (16%) of feet and 35/56 (63%) of hand x-rays. Erosions were seen in 3/56 (6%) of feet and in 22/56 (39%) of hand x-rays. Significant correlation was seen between joints space narrowing, joint erosions, and disease duration. Radiographic changes in hands and feet of Saudi rheumatoid arthritis patients are less severe than those reported from the West, and the pattern is also different with less affection of the feet. (author)

Does an eye-hand coordination test have added value as part of talent identification in table tennis? A validity and reproducibility study.

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Faber, Irene R; Oosterveld, Frits G J; Nijhuis-Van der Sanden, Maria W G

2014-01-01

This study investigated the added value, i.e. discriminative and concurrent validity and reproducibility, of an eye-hand coordination test relevant to table tennis as part of talent identification. Forty-three table tennis players (7-12 years) from national (n = 13), regional (n = 11) and local training centres (n = 19) participated. During the eye-hand coordination test, children needed to throw a ball against a vertical positioned table tennis table with one hand and to catch the ball correctly with the other hand as frequently as possible in 30 seconds. Four different test versions were assessed varying the distance to the table (1 or 2 meter) and using a tennis or table tennis ball. 'Within session' reproducibility was estimated for the two attempts of the initial tests and ten youngsters were retested after 4 weeks to estimate 'between sessions' reproducibility. Validity analyses using age as covariate showed that players from the national and regional centres scored significantly higher than players from the local centre in all test versions (ptalent identification appears to be the version with a table tennis ball at 1 meter regarding the psychometric characteristics evaluated. Longitudinal studies are necessary to evaluate the predictive value of this test.

Modulation of hand aperture during reaching in persons with incomplete cervical spinal cord injury.

Science.gov (United States)

Stahl, Victoria A; Hayes, Heather B; Buetefisch, Cathrin M; Wolf, Steven L; Trumbower, Randy D

2015-03-01

The intact neuromotor system prepares for object grasp by first opening the hand to an aperture that is scaled according to object size and then closing the hand around the object. After cervical spinal cord injury (SCI), hand function is significantly impaired, but the degree to which object-specific hand aperture scaling is affected remains unknown. Here, we hypothesized that persons with incomplete cervical SCI have a reduced maximum hand opening capacity but exhibit novel neuromuscular coordination strategies that permit object-specific hand aperture scaling during reaching. To test this hypothesis, we measured hand kinematics and surface electromyography from seven muscles of the hand and wrist during attempts at maximum hand opening as well as reaching for four balls of different diameters. Our results showed that persons with SCI exhibited significantly reduced maximum hand aperture compared to able-bodied (AB) controls. However, persons with SCI preserved the ability to scale peak hand aperture with ball size during reaching. Persons with SCI also used distinct muscle coordination patterns that included increased co-activity of flexors and extensors at the wrist and hand compared to AB controls. These results suggest that motor planning for aperture modulation is preserved even though execution is limited by constraints on hand opening capacity and altered muscle co-activity. Thus, persons with incomplete cervical SCI may benefit from rehabilitation aimed at increasing hand opening capacity and reducing flexor-extensor co-activity at the wrist and hand.

Two thumbs and one index: A comparison of manual coordination in touch-typing and mobile-typing.

Science.gov (United States)

Cerni, Tania; Longcamp, Marieke; Job, Remo

2016-06-01

It has been extensively demonstrated that in touch-typing, manual alternation is performed faster than manual repetition (see i.e. Rumelhart & Norman, 1982), due to parallel activation of successive keystrokes. In this experiment, we tested whether the manual coordination patterns typical of touch-typing can be observed in mobile-typing. We recruited skilled touch-typists and divided them into two groups depending on their typing habits on the mobile device. The "one-hand" group typed with one index finger on the mobile, and therefore produced words exclusively through manual repetition. The "two-hands" group used two thumbs, and therefore produced words through a combination of mobile-typing repetitions and alternations. The two groups were tested in a typing to dictation task with both a standard keyboard and a mobile keyboard. Results showed that manual alternation and manual repetition patterns are similar in touch-typing and in mobile-typing. For the "two-hands" group, the mean interkeystroke intervals (IKIs) for touch-typing decreased as manual alterations in words increased in both touch- and mobile-typing. The "one-hand" group showed an opposite pattern in mobile-typing. Bigram frequency was correlated with IKIs per bigrams in both tasks and groups, but the correlation for the "one-hand" group in mobile-typing was different. Our results suggest that manual coordination processes are the same in touch-typing and in mobile-typing despite different effectors, provided that both hands are used to type. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of Ving Tsun Chinese Martial Art Training on Upper Extremity Muscle Strength and Eye-Hand Coordination in Community-Dwelling Middle-Aged and Older Adults: A Pilot Study

Science.gov (United States)

Ng, Shamay S. M.; Cheng, Yoyo T. Y.; Yu, Esther Y. T.; Chow, Gary C. C.; Chak, Yvonne T. C.; Chan, Ivy K. Y.; Zhang, Joni; Macfarlane, Duncan

2016-01-01

Objectives. To evaluate the effects of Ving Tsun (VT) martial art training on the upper extremity muscle strength and eye-hand coordination of middle-aged and older adults. Methods. This study used a nonequivalent pretest-posttest control group design. Forty-two community-dwelling healthy adults participated in the study; 24 (mean age ± SD = 68.5 ± 6.7 years) underwent VT training for 4 weeks (a supervised VT session twice a week, plus daily home practice), and 18 (mean age ± SD = 72.0 ± 6.7 years) received no VT training and acted as controls. Shoulder and elbow isometric muscle strength and eye-hand coordination were evaluated using the Lafayette Manual Muscle Test System and a computerized finger-pointing test, respectively. Results. Elbow extensor peak force increased by 13.9% (P = 0.007) in the VT group and the time to reach peak force decreased (9.9%) differentially in the VT group compared to the control group (P = 0.033). For the eye-hand coordination assessment outcomes, reaction time increased by 2.9% in the VT group and decreased by 5.3% in the control group (P = 0.002). Conclusions. Four weeks of VT training could improve elbow extensor isometric peak force and the time to reach peak force but not eye-hand coordination in community-dwelling middle-aged and older adults. PMID:27525020

Effects of Ving Tsun Chinese Martial Art Training on Upper Extremity Muscle Strength and Eye-Hand Coordination in Community-Dwelling Middle-Aged and Older Adults: A Pilot Study.

Science.gov (United States)

Fong, Shirley S M; Ng, Shamay S M; Cheng, Yoyo T Y; Wong, Janet Y H; Yu, Esther Y T; Chow, Gary C C; Chak, Yvonne T C; Chan, Ivy K Y; Zhang, Joni; Macfarlane, Duncan; Chung, Louisa M Y

2016-01-01

Objectives. To evaluate the effects of Ving Tsun (VT) martial art training on the upper extremity muscle strength and eye-hand coordination of middle-aged and older adults. Methods. This study used a nonequivalent pretest-posttest control group design. Forty-two community-dwelling healthy adults participated in the study; 24 (mean age ± SD = 68.5 ± 6.7 years) underwent VT training for 4 weeks (a supervised VT session twice a week, plus daily home practice), and 18 (mean age ± SD = 72.0 ± 6.7 years) received no VT training and acted as controls. Shoulder and elbow isometric muscle strength and eye-hand coordination were evaluated using the Lafayette Manual Muscle Test System and a computerized finger-pointing test, respectively. Results. Elbow extensor peak force increased by 13.9% (P = 0.007) in the VT group and the time to reach peak force decreased (9.9%) differentially in the VT group compared to the control group (P = 0.033). For the eye-hand coordination assessment outcomes, reaction time increased by 2.9% in the VT group and decreased by 5.3% in the control group (P = 0.002). Conclusions. Four weeks of VT training could improve elbow extensor isometric peak force and the time to reach peak force but not eye-hand coordination in community-dwelling middle-aged and older adults.

Effects of Ving Tsun Chinese Martial Art Training on Upper Extremity Muscle Strength and Eye-Hand Coordination in Community-Dwelling Middle-Aged and Older Adults: A Pilot Study

Directory of Open Access Journals (Sweden)

Shirley S. M. Fong

2016-01-01

Full Text Available Objectives. To evaluate the effects of Ving Tsun (VT martial art training on the upper extremity muscle strength and eye-hand coordination of middle-aged and older adults. Methods. This study used a nonequivalent pretest-posttest control group design. Forty-two community-dwelling healthy adults participated in the study; 24 (mean age ± SD = 68.5±6.7 years underwent VT training for 4 weeks (a supervised VT session twice a week, plus daily home practice, and 18 (mean age ± SD = 72.0±6.7 years received no VT training and acted as controls. Shoulder and elbow isometric muscle strength and eye-hand coordination were evaluated using the Lafayette Manual Muscle Test System and a computerized finger-pointing test, respectively. Results. Elbow extensor peak force increased by 13.9% (P=0.007 in the VT group and the time to reach peak force decreased (9.9% differentially in the VT group compared to the control group (P=0.033. For the eye-hand coordination assessment outcomes, reaction time increased by 2.9% in the VT group and decreased by 5.3% in the control group (P=0.002. Conclusions. Four weeks of VT training could improve elbow extensor isometric peak force and the time to reach peak force but not eye-hand coordination in community-dwelling middle-aged and older adults.

Intersegmental coordination of cockroach locomotion: adaptive control of centrally coupled pattern generator circuits

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Einat eFuchs

2011-01-01

Full Text Available Animals’ ability to demonstrate both stereotyped and adaptive locomotor behavior is largely dependent on the interplay between centrally-generated motor patterns and the sensory inputs that shape them. We utilized a combined experimental and theoretical approach to investigate the relative importance of CPG interconnections vs. intersegmental afferents in the cockroach: an animal that is renowned for rapid and stable locomotion. We simultaneously recorded coxal levator and depressor motor neurons (MN in the thoracic ganglia of Periplaneta americana, while sensory feedback was completely blocked or allowed only from one intact stepping leg. In the absence of sensory feedback, we observed a coordination pattern with consistent phase relationship that shares similarities with a double tripod gait, suggesting central, feedforward control. This intersegmental coordination pattern was then reinforced in the presence of sensory feedback from a single stepping leg. Specifically, we report on transient stabilization of phase differences between activity recorded in the middle and hind thoracic MN following individual front-leg steps, suggesting a role for afferent phasic information in the coordination of motor circuits at the different hemiganglia. Data were further analyzed using stochastic models of coupled oscillators and maximum likelihood techniques to estimate underlying physiological parameters, such as uncoupled endogenous frequencies of hemisegmental oscillators and coupling strengths and directions. We found that descending ipsilateral coupling is stronger than ascending coupling, while left-right coupling in both the meso- and meta-thoracic ganglia appear to be symmetrical. We discuss our results in comparison with recent findings in stick insects that share similar neural and body architectures, and argue that the two species may exemplify opposite extremes of a fast-slow locomotion continuum, mediated through different intersegmental

Cerebral lateralization for the processing of spatial coordinates and categories in left-and right-handers.

Science.gov (United States)

LAENG, B; PETERS, M

1995-04-01

Subjects judged whether a tachistoscopially lateralized drawing was identical or different to a drawing seen immediately before in free vision. The drawings depicted natural objects (e.g. animals). On half of the trials the tachistoscopic drawing presented the same objects but either the categorical or the coordinate spatial relations (according to Kosslyn's definitions [23]) between the objects were transformed. In the first experiment 38 right-handed subjects (half males and half females) were tested. Categorical judgements were faster when the match drawing appeared in the right visual field, whereas coordinate judgements were faster when the match drawing appeared in the left visual field. In the second experiment 26 right-handed and 40 left-handed subjects participated. Almost all the subjects were female. Right-handed subjects replicated the findings of the subjects in the first experiment. However, the LHs did not show any difference in response times between spatial conditions and visual fields. These findings support Kosslyn's hypothesis that the left and right hemispheres are specialized respectively for processing categorical and coordinate spatial relations. Moreover, they also suggest that this lateralization pattern is not typical of left-handers.

Hand-eye coordination of a robot for the automatic inspection of steam-generator tubes in nuclear power plants

International Nuclear Information System (INIS)

Choi, D.H.; Song, Y.C.; Kim, J.H.; Kim, J.G.

2004-01-01

The inspection of steam-generator tubes in nuclear power plants needs to collect test signals in a highly radiated region that is not accessible by humans. In general, a robot equipped with a camera and a test probe is used to handle such a dangerous environment. The robot moves the probe to right below a tube to be inspected and then the probe is inserted into the tube. The inspection signals are acquired while the probe is pulling back. Currently, an operator in a control room controls all the process remotely. To make a fully automatic inspection system, first of all, a control mechanism is needed to position the probe to the proper location. This is so called a hand-eye coordination problem. In this paper, a hand-eye coordination method for a robot has been presented. The proposed method consists of the two consecutive control modes: rough positioning and fine-tuning. The rough positioning controller tries to position its probe near a target place using kinematics information and the known environments, and then the fine-tuning controller tries to adjust the probe to the target using the image acquired by the camera attached to the robot. The usefulness of the proposed method has been tested and verified through experiments. (orig.)

Frequency of β-lactamase enzyme and antibiogram pattern in bacterial flora isolated from staffs hands

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Shilla Jalalpoor

2011-12-01

Full Text Available Background: β-lactamase is an enzyme that can inactivate β–Lactam family antibiotics. High prevalence of β-lactamase producer bacteria on the staff hands, due to antibiotic resistance and nosocomial infection in hospitalized patients. The objective of this study was to assess the frequency of β-lactamase positive bacteria and antibiogram pattern in bacterial flora isolated from staff hands of the Al-Zahra hospital in Isfahan.Materials and Method: This laboratory research was performed during of 2005-2007 in Al-Zahra hospital in Isfahan. According to statistical formula, we randomly selected 80 samples from staff hands. Staff hand samples collected with finger print method. Bacterial identification was performed with microbiological methods and β–lactamase production was performed with Acidometric method and antibiogram pattern was performed with Kirby Bauer method.Results: According to the acidometric test results of 80 isolated staff hands, 61.85% of strains produce β–lactamase. Staphylococcus spp., Bacillus spp. and Enterobacteriaceae were the most important producers respectively (70.83%, 64.72% and 50%. According to antibiogram test results, penicillin and vancomycin had the highest and lowest resistance. Conclusion: High frequency of β–lactamase in bacterial survey represents colonization of bacteria in staff hands; may be due to facility transmission β–lactamase plasmid genes in bacteria. We suggest better hand washing in hospitals and prescription of β–lactame antibiotics was based only on antibiogram results

The cortical activation pattern by a rehabilitation robotic hand: a functional NIRS study.

Science.gov (United States)

Chang, Pyung-Hun; Lee, Seung-Hee; Gu, Gwang Min; Lee, Seung-Hyun; Jin, Sang-Hyun; Yeo, Sang Seok; Seo, Jeong Pyo; Jang, Sung Ho

2014-01-01

Clarification of the relationship between external stimuli and brain response has been an important topic in neuroscience and brain rehabilitation. In the current study, using functional near infrared spectroscopy (fNIRS), we attempted to investigate cortical activation patterns generated during execution of a rehabilitation robotic hand. Ten normal subjects were recruited for this study. Passive movements of the right fingers were performed using a rehabilitation robotic hand at a frequency of 0.5 Hz. We measured values of oxy-hemoglobin (HbO), deoxy-hemoglobin (HbR) and total-hemoglobin (HbT) in five regions of interest: the primary sensory-motor cortex (SM1), hand somatotopy of the contralateral SM1, supplementary motor area (SMA), premotor cortex (PMC), and prefrontal cortex (PFC). HbO and HbT values indicated significant activation in the left SM1, left SMA, left PMC, and left PFC during execution of the rehabilitation robotic hand (uncorrected, p < 0.01). By contrast, HbR value indicated significant activation only in the hand somatotopic area of the left SM1 (uncorrected, p < 0.01). Our results appear to indicate that execution of the rehabilitation robotic hand could induce cortical activation.

The cortical activation pattern by a rehabilitation robotic hand : A functional NIRS study

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Pyung Hun eChang

2014-02-01

Full Text Available Introduction: Clarification of the relationship between external stimuli and brain response has been an important topic in neuroscience and brain rehabilitation. In the current study, using functional near infrared spectroscopy (fNIRS, we attempted to investigate cortical activation patterns generated during execution of a rehabilitation robotic hand. Methods: Ten normal subjects were recruited for this study. Passive movements of the right fingers were performed using a rehabilitation robotic hand at a frequency of 0.5 Hz. We measured values of oxy-hemoglobin(HbO, deoxy-hemoglobin(HbR and total-hemoglobin(HbT in five regions of interest: the primary sensory-motor cortex (SM1, hand somatotopy of the contralateral SM1, supplementary motor area (SMA, premotor cortex (PMC, and prefrontal cortex (PFC. Results: HbO and HbT values indicated significant activation in the left SM1, left SMA, left PMC, and left PFC during execution of the rehabilitation robotic hand(uncorrected, pConclusions: Our results appear to indicate that execution of the rehabilitation robotic hand could induce cortical activation.

Research on direct calibration method of eye-to-hand system of robot

Science.gov (United States)

Hu, Xiaoping; Xie, Ke; Peng, Tao

2013-10-01

In the position-based visual servoing control for robot, the hand-eye calibration is very important because it can affect the control precision of the system. According to the robot with eye-to-hand stereovision system, this paper proposes a direct method of hand-eye calibration. The method utilizes the triangle measuring principle to solve the coordinates in the camera coordinate system of scene point. It calculates the estimated coordinates by the hand-eye calibration equation set which indicates the transformational relation from the robot to the camera coordinate system, and then uses the error of actual and estimated coordinates to establish the objective function. Finally the method substitutes the parameters into the function repeatedly until it converged to optimize the result. The related experiment compared the measured coordinates with the actual coordinates, shows the efficiency and the precision of it.

Patterns of hand preference for pairs of actions and the classification of handedness.

Science.gov (United States)

Annett, Marian

2009-08-01

Pairs of actions such as write x throw and throw x racquet were examined for items of the Annett hand preference questionnaire (AHPQ). Right (R) and left (L) responses were described for frequencies of RR, RL, LR, and LL pairings (write x throw etc.) in a large representative combined sample with the aim of discovering the distribution over the population as a whole. The frequencies of RL pairings varied significantly over the different item pairs but the frequencies of LR pairings were fairly constant. An important difference was found between primary actions (originally write, throw, racquet, match, toothbrush, hammer with the later addition of scissors for right-handers) and non-primary actions (needle and thread, broom, spade, dealing playing cards, and unscrewing the lid of a jar). For primary actions, there were similar numbers of right and left writers using the 'other' hand. For non-primary actions more right-handers used the left hand than for primary actions but more left-handers did not use the right hand. That is, different frequencies of response to primary versus non-primary actions were found for right-handers but not for left-handers. The pattern of findings was repeated for a corresponding analysis of left-handed throwing x AHPQ actions. The findings have implications for the classification of hand preferences and for analyses of the nature of hand skill.

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.

Robotic Hand-Assisted Training for Spinal Cord Injury Driven by Myoelectric Pattern Recognition: A Case Report.

Science.gov (United States)

Lu, Zhiyuan; Tong, Kai-Yu; Shin, Henry; Stampas, Argyrios; Zhou, Ping

2017-10-01

A 51-year-old man with an incomplete C6 spinal cord injury sustained 26 yrs ago attended twenty 2-hr visits over 10 wks for robot-assisted hand training driven by myoelectric pattern recognition. In each visit, his right hand was assisted to perform motions by an exoskeleton robot, while the robot was triggered by his own motion intentions. The hand robot was designed for this study, which can perform six kinds of motions, including hand closing/opening; thumb, index finger, and middle finger closing/opening; and middle, ring, and little fingers closing/opening. After the training, his grip force increased from 13.5 to 19.6 kg, his pinch force remained the same (5.0 kg), his score of Box and Block test increased from 32 to 39, and his score from the Graded Redefined Assessment of Strength, Sensibility, and Prehension test Part 4.B increased from 22 to 24. He accomplished the tasks in the Graded Redefined Assessment of Strength, Sensibility, and Prehension test Part 4.B 28.8% faster on average. The results demonstrate the feasibility and effectiveness of robot-assisted training driven by myoelectric pattern recognition after spinal cord injury.

Effects of conventional neurological treatment and a virtual reality training program on eye-hand coordination in children with cerebral palsy

OpenAIRE

Shin, Ji-won; Song, Gui-bin; Hwangbo, Gak

2015-01-01

[Purpose] The purpose of the study was to evaluate the effects of conventional neurological treatment and a virtual reality training program on eye-hand coordination in children with cerebral palsy. [Subjects] Sixteen children (9 males, 7 females) with spastic diplegic cerebral palsy were recruited and randomly assigned to the conventional neurological physical therapy group (CG) and virtual reality training group (VRG). [Methods] Eight children in the control group performed 45 minutes of th...

Hand/Eye Coordination For Fine Robotic Motion

Science.gov (United States)

Lokshin, Anatole M.

1992-01-01

Fine motions of robotic manipulator controlled with help of visual feedback by new method reducing position errors by order of magnitude. Robotic vision subsystem includes five cameras: three stationary ones providing wide-angle views of workspace and two mounted on wrist of auxiliary robot arm. Stereoscopic cameras on arm give close-up views of object and end effector. Cameras measure errors between commanded and actual positions and/or provide data for mapping between visual and manipulator-joint-angle coordinates.

Perception and action in swimming: Effects of aquatic environment on upper limb inter-segmental coordination.

Science.gov (United States)

Guignard, Brice; Rouard, Annie; Chollet, Didier; Ayad, Omar; Bonifazi, Marco; Dalla Vedova, Dario; Seifert, Ludovic

2017-10-01

This study assessed perception-action coupling in expert swimmers by focusing on their upper limb inter-segmental coordination in front crawl. To characterize this coupling, we manipulated the fluid flow and compared trials performed in a swimming pool and a swimming flume, both at a speed of 1.35ms -1 . The temporal structure of the stroke cycle and the spatial coordination and its variability for both hand/lower arm and lower arm/upper arm couplings of the right body side were analyzed as a function of fluid flow using inertial sensors positioned on the corresponding segments. Swimmers' perceptions in both environments were assessed using the Borg rating of perceived exertion scale. Results showed that manipulating the swimming environment impacts low-order (e.g., temporal, position, velocity or acceleration parameters) and high-order (i.e., spatial-temporal coordination) variables. The average stroke cycle duration and the relative duration of the catch and glide phases were reduced in the flume trial, which was perceived as very intense, whereas the pull and push phases were longer. Of the four coordination patterns (in-phase, anti-phase, proximal and distal: when the appropriate segment is leading the coordination of the other), flume swimming demonstrated more in-phase coordination for the catch and glide (between hand and lower arm) and recovery (hand/lower arm and lower arm/upper arm couplings). Conversely, the variability of the spatial coordination was not significantly different between the two environments, implying that expert swimmers maintain consistent and stable coordination despite constraints and whatever the swimming resistances. Investigations over a wider range of velocities are needed to better understand coordination dynamics when the aquatic environment is modified by a swimming flume. Since the design of flumes impacts significantly the hydrodynamics and turbulences of the fluid flow, previous results are mainly related to the

Coordination Processes in International Organisations

DEFF Research Database (Denmark)

Nedergaard, Peter

2008-01-01

The EU is not a member of the International Labour Organisation (ILO), but relatively elaborate EU coordination takes place anyway. This paper addresses two research questions: 1) How is it possible to evaluate the coordination of the EU in its specific observable configuration in the ILO?, and 2......-à-vis their principals, the Member States. The Commission is the leading agent in the phase leading up to the Conference; the Presidency then takes over. On the one hand, due to the Treaty obligations and their interpretations by the Court of Justice, both the Presidency and the Commission are kept within tight limits...... by the principals. On the other hand, both before and during the Conference, the Member States accept the so-called discursive coordination of the Commission, which seems to be of great (but often neglected) importance. Owing to the organisational set-up in which coordination takes place, the EU is able...

Computational intelligence in multi-feature visual pattern recognition hand posture and face recognition using biologically inspired approaches

CERN Document Server

Pisharady, Pramod Kumar; Poh, Loh Ai

2014-01-01

This book presents a collection of computational intelligence algorithms that addresses issues in visual pattern recognition such as high computational complexity, abundance of pattern features, sensitivity to size and shape variations and poor performance against complex backgrounds. The book has 3 parts. Part 1 describes various research issues in the field with a survey of the related literature. Part 2 presents computational intelligence based algorithms for feature selection and classification. The algorithms are discriminative and fast. The main application area considered is hand posture recognition. The book also discusses utility of these algorithms in other visual as well as non-visual pattern recognition tasks including face recognition, general object recognition and cancer / tumor classification. Part 3 presents biologically inspired algorithms for feature extraction. The visual cortex model based features discussed have invariance with respect to appearance and size of the hand, and provide good...

Behavioral Impact of Unisensory and Multisensory Audio-Tactile Events: Pros and Cons for Interlimb Coordination in Juggling

Science.gov (United States)

Zelic, Gregory; Mottet, Denis; Lagarde, Julien

2012-01-01

Recent behavioral neuroscience research revealed that elementary reactive behavior can be improved in the case of cross-modal sensory interactions thanks to underlying multisensory integration mechanisms. Can this benefit be generalized to an ongoing coordination of movements under severe physical constraints? We choose a juggling task to examine this question. A central issue well-known in juggling lies in establishing and maintaining a specific temporal coordination among balls, hands, eyes and posture. Here, we tested whether providing additional timing information about the balls and hands motions by using external sound and tactile periodic stimulations, the later presented at the wrists, improved the behavior of jugglers. One specific combination of auditory and tactile metronome led to a decrease of the spatiotemporal variability of the juggler's performance: a simple sound associated to left and right tactile cues presented antiphase to each other, which corresponded to the temporal pattern of hands movement in the juggling task. A contrario, no improvements were obtained in the case of other auditory and tactile combinations. We even found a degraded performance when tactile events were presented alone. The nervous system thus appears able to integrate in efficient way environmental information brought by different sensory modalities, but only if the information specified matches specific features of the coordination pattern. We discuss the possible implications of these results for the understanding of the neuronal integration process implied in audio-tactile interaction in the context of complex voluntary movement, and considering the well-known gating effect of movement on vibrotactile perception. PMID:22384211

Behavioral impact of unisensory and multisensory audio-tactile events: pros and cons for interlimb coordination in juggling.

Directory of Open Access Journals (Sweden)

Gregory Zelic

Full Text Available Recent behavioral neuroscience research revealed that elementary reactive behavior can be improved in the case of cross-modal sensory interactions thanks to underlying multisensory integration mechanisms. Can this benefit be generalized to an ongoing coordination of movements under severe physical constraints? We choose a juggling task to examine this question. A central issue well-known in juggling lies in establishing and maintaining a specific temporal coordination among balls, hands, eyes and posture. Here, we tested whether providing additional timing information about the balls and hands motions by using external sound and tactile periodic stimulations, the later presented at the wrists, improved the behavior of jugglers. One specific combination of auditory and tactile metronome led to a decrease of the spatiotemporal variability of the juggler's performance: a simple sound associated to left and right tactile cues presented antiphase to each other, which corresponded to the temporal pattern of hands movement in the juggling task. A contrario, no improvements were obtained in the case of other auditory and tactile combinations. We even found a degraded performance when tactile events were presented alone. The nervous system thus appears able to integrate in efficient way environmental information brought by different sensory modalities, but only if the information specified matches specific features of the coordination pattern. We discuss the possible implications of these results for the understanding of the neuronal integration process implied in audio-tactile interaction in the context of complex voluntary movement, and considering the well-known gating effect of movement on vibrotactile perception.

A Study of Hand Back Skin Texture Patterns for Personal Identification and Gender Classification

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Jin Xie

2012-06-01

Full Text Available Human hand back skin texture (HBST is often consistent for a person and distinctive from person to person. In this paper, we study the HBST pattern recognition problem with applications to personal identification and gender classification. A specially designed system is developed to capture HBST images, and an HBST image database was established, which consists of 1,920 images from 80 persons (160 hands. An efficient texton learning based method is then presented to classify the HBST patterns. First, textons are learned in the space of filter bank responses from a set of training images using the -minimization based sparse representation (SR technique. Then, under the SR framework, we represent the feature vector at each pixel over the learned dictionary to construct a representation coefficient histogram. Finally, the coefficient histogram is used as skin texture feature for classification. Experiments on personal identification and gender classification are performed by using the established HBST database. The results show that HBST can be used to assist human identification and gender classification.

Coordinate Representations for Interference Reduction in Motor Learning.

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Sang-Hoon Yeo

Full Text Available When opposing force fields are presented alternately or randomly across trials for identical reaching movements, subjects learn neither force field, a behavior termed 'interference'. Studies have shown that a small difference in the endpoint posture of the limb reduces this interference. However, any difference in the limb's endpoint location typically changes the hand position, joint angles and the hand orientation making it ambiguous as to which of these changes underlies the ability to learn dynamics that normally interfere. Here we examine the extent to which each of these three possible coordinate systems--Cartesian hand position, shoulder and elbow joint angles, or hand orientation--underlies the reduction in interference. Subjects performed goal-directed reaching movements in five different limb configurations designed so that different pairs of these configurations involved a change in only one coordinate system. By specifically assigning clockwise and counter-clockwise force fields to the configurations we could create three different conditions in which the direction of the force field could only be uniquely distinguished in one of the three coordinate systems. We examined the ability to learn the two fields based on each of the coordinate systems. The largest reduction of interference was observed when the field direction was linked to the hand orientation with smaller reductions in the other two conditions. This result demonstrates that the strongest reduction in interference occurred with changes in the hand orientation, suggesting that hand orientation may have a privileged role in reducing motor interference for changes in the endpoint posture of the limb.

Coordinating towards a Common Good

Science.gov (United States)

Santos, Francisco C.; Pacheco, Jorge M.

2010-09-01

Throughout their life, humans often engage in collective endeavors ranging from family related issues to global warming. In all cases, the tragedy of the commons threatens the possibility of reaching the optimal solution associated with global cooperation, a scenario predicted by theory and demonstrated by many experiments. Using the toolbox of evolutionary game theory, I will address two important aspects of evolutionary dynamics that have been neglected so far in the context of public goods games and evolution of cooperation. On one hand, the fact that often there is a threshold above which a public good is reached [1, 2]. On the other hand, the fact that individuals often participate in several games, related to the their social context and pattern of social ties, defined by a social network [3, 4, 5]. In the first case, the existence of a threshold above which collective action is materialized dictates a rich pattern of evolutionary dynamics where the direction of natural selection can be inverted compared to standard expectations. Scenarios of defector dominance, pure coordination or coexistence may arise simultaneously. Both finite and infinite population models are analyzed. In networked games, cooperation blooms whenever the act of contributing is more important than the effort contributed. In particular, the heterogeneous nature of social networks naturally induces a symmetry breaking of the dilemmas of cooperation, as contributions made by cooperators may become contingent on the social context in which the individual is embedded. This diversity in context provides an advantage to cooperators, which is particularly strong when both wealth and social ties follow a power-law distribution, providing clues on the self-organization of social communities. Finally, in both situations, it can be shown that individuals no longer play a defection dominance dilemma, but effectively engage in a general N-person coordination game. Even if locally defection may seem

Hand assessment with the E-Cone in rheumatoid arthritis and hand osteoarthritis

NARCIS (Netherlands)

van Merendonk, N.; van Alebeek, V.; Spreeuwers, Lieuwe Jan; Spreeuwers, D.; Kroon, P.J.; Roorda, L.; Dekker, J.; Hoeksma, A.F.

2013-01-01

Background: Rheumatoid arthritis (RA) is a systemic inflammatory, progressive disease resulting in deformities of the hand. Besides synovitis, tenosynovitis of the extrinsic flexor tendons is one of the initial features of RA, leading to friction and consequently to an imbalanced coordination of the

Coordination models Orc and Reo compared

NARCIS (Netherlands)

J.M.P. Proença (Jose); D.G. Clarke (David)

2008-01-01

htmlabstractOrc and Reo are two complementary approaches to the problem of coordinating components or services. On one hand, Orc is highly asynchronous, dynamic, and based on ephemeral connections to services. On the other hand, Reo is based on the interplay between synchronization and mutual

Hybrid Architecture for Coordination of AGVs in FMS

Directory of Open Access Journals (Sweden)

Eduardo G. Hernandez-Martinez

2014-03-01

Full Text Available This paper presents a hybrid control architecture that coordinates the motion of groups of automated guided vehicles in flexible manufacturing systems. The high-level control is based on a Petri net model, using the industrial standard ISA-95, obtaining a task-based coordination of equipment and storage considering process restrictions, logical precedences, shared resources and the assignment of robots to move workpieces individually or in subgroups. On the other hand, in the low-level control, three basic control laws are designed for unicycle-type robots in order to achieve desired formation patterns and marching behaviours, avoiding inter-robot collisions. The control scheme combines the task assignment for the robots obtained from the discrete-event model and the implementation of formation and marching continuous control laws applied to the motion of the mobile robots. The hybrid architecture is implemented and validated for the case of a flexible manufacturing system and four mobile robots using a virtual reality platform.

Does an eye-hand coordination test have added value as part of talent identification in table tennis? A validity and reproducibility study.

Directory of Open Access Journals (Sweden)

Irene R Faber

Full Text Available This study investigated the added value, i.e. discriminative and concurrent validity and reproducibility, of an eye-hand coordination test relevant to table tennis as part of talent identification. Forty-three table tennis players (7-12 years from national (n = 13, regional (n = 11 and local training centres (n = 19 participated. During the eye-hand coordination test, children needed to throw a ball against a vertical positioned table tennis table with one hand and to catch the ball correctly with the other hand as frequently as possible in 30 seconds. Four different test versions were assessed varying the distance to the table (1 or 2 meter and using a tennis or table tennis ball. 'Within session' reproducibility was estimated for the two attempts of the initial tests and ten youngsters were retested after 4 weeks to estimate 'between sessions' reproducibility. Validity analyses using age as covariate showed that players from the national and regional centres scored significantly higher than players from the local centre in all test versions (p<0.05. The tests at 1 meter demonstrated better discriminative ability than those at 2 meter. While all tests but one had a positive significant association with competition outcome, which were corrected for age influences, the version with a table tennis ball at 1 meter showed the highest association (r = 0.54; p = 0.001. Differences between the first and second attempts were comparable for all test versions (between -8 and +7 repetitions with ICC's ranging from 0.72 to 0.87. The smallest differences were found for the test with a table tennis ball at 1 meter (between -3 and +3 repetitions. Best test version as part of talent identification appears to be the version with a table tennis ball at 1 meter regarding the psychometric characteristics evaluated. Longitudinal studies are necessary to evaluate the predictive value of this test.

Pattern Differences of Small Hand Muscle Atrophy in Amyotrophic Lateral Sclerosis and Mimic Disorders.

Science.gov (United States)

Fang, Jia; Liu, Ming-Sheng; Guan, Yu-Zhou; Du, Hua; Li, Ben-Hong; Cui, Bo; Ding, Qing-Yun; Cui, Li-Ying

2016-04-05

Amyotrophic lateral sclerosis (ALS) and some mimic disorders, such as distal-type cervical spondylotic amyotrophy (CSA), Hirayama disease (HD), and spinobulbar muscular atrophy (SBMA) may present with intrinsic hand muscle atrophy. This study aimed to investigate different patterns of small hand muscle involvement in ALS and some mimic disorders. We compared the abductor digiti minimi/abductor pollicis brevis (ADM/APB) compound muscle action potential (CMAP) ratios between 200 ALS patients, 95 patients with distal-type CSA, 88 HD patients, 43 SBMA patients, and 150 normal controls. The ADM/APB CMAP amplitude ratio was significantly higher in the ALS patients (P mimic disorders presumably reflect distinct pathophysiological mechanisms underlying different disorders, and may aid in distinguishing between ALS and mimic disorders.

Retrospectives: Ethics and the Invisible Hand

OpenAIRE

Jerry Evensky

1993-01-01

As modern economists, we use Adam Smith's "invisible hand" metaphor confident that we all know what it means in our discourse: it reflects our admiration for the elegant and smooth functioning of the market system as a coordinator of autonomous individual choices in an interdependent world. But in Adam Smith's moral philosophy, the invisible hand has a much broader responsibility: if individuals are to enjoy the fruits of a classical liberal society, the invisible hand must not only coordinat...

SPASTICITY PATTERNS OF HAND MUSCLES AND BOTULINUM TOXIN THERAPY APPLICATION IN PATIENTS WITH CEREBRAL PALSY WITH UPPER LIMB INVOLVEMENT

Directory of Open Access Journals (Sweden)

O. A. Klochkova

2013-01-01

Full Text Available Botulinum toxin therapy is an effective and safe method of treatment of local spasticity in patients with cerebral palsy (CP. Calculation of botulinum toxin A (BTA dosage based on the spasticity patterns and functional capabilities of the patient proved effective for the hypertonic lower limb muscle spasm treatment and is being applied to BTA injections in hand muscles more often. The article presents contemporary scientific data and results of the original study of BTA injections efficacy for pathologic tension reduction in hand muscles of 52 patients with CP. The authors give detailed description of the upper limb spasticity patterns, their frequency and role in the pathological movement pattern formation. The authors propose BTA dosage calculation for the functional segments of upper limbs, which allows minimizing the total amount of the administered drug and avoiding excessive weakness. The authors have also conducted a follow-up analysis of changes in hand muscle tone for the period of 6 months after the first BTA injection, compared results of botulinum toxin therapy at various clinical forms of CP and given recommendations on the optimum duration of the follow-up period.

Occupational hand injury patterns at Avicenna University Hospital

Directory of Open Access Journals (Sweden)

Abdelmoughit Echchaoui

2017-08-01

Conclusion: Hand injuries are common in the workplace and affect mostly active and working-age people. Preventive measures are required and should receive appropriate attention and resources. [Hand Microsurg 2017; 6(2.000: 75-80

Hand aperture patterns in prehension

NARCIS (Netherlands)

Bongers, Raoul M.; Zaal, Frank T. J. M.; Jeannerod, Marc

Although variations in the standard prehensile pattern can be found in the literature, these alternative patterns have never been studied systematically. This was the goal of the current paper. Ten participants picked up objects with a pincer grip. Objects (3, 5, or 7 cm in diameter) were placed at

THE VISIBLE HAND? THE ECONOMICS OF ALFRED CHANDLER

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Don Matthews

2000-01-01

Full Text Available In his great work The Visible Hand: The Managerial Revolution in American Business, Alfred Chandler argues that the modern managerial enterprise replaced the invisible hand of the market in coordinating the activities and allocating the resources of the U.S. economy. But Chandler’s view of the invisible hand of the market is much too narrow. The modern managerial enterprise is not a substitute for the invisible hand of the market but an integral part of it. The Visible Hand is actually a history of the invisible hand of the market.

Development of a model of machine hand eye coordination and program specifications for a topological machine vision system

Science.gov (United States)

1972-01-01

A unified approach to computer vision and manipulation is developed which is called choreographic vision. In the model, objects to be viewed by a projected robot in the Viking missions to Mars are seen as objects to be manipulated within choreographic contexts controlled by a multimoded remote, supervisory control system on Earth. A new theory of context relations is introduced as a basis for choreographic programming languages. A topological vision model is developed for recognizing objects by shape and contour. This model is integrated with a projected vision system consisting of a multiaperture image dissector TV camera and a ranging laser system. System program specifications integrate eye-hand coordination and topological vision functions and an aerospace multiprocessor implementation is described.

Atypical speech lateralization in adults with developmental coordination disorder demonstrated using functional transcranial Doppler ultrasound.

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Hodgson, Jessica C; Hudson, John M

2017-03-01

Research using clinical populations to explore the relationship between hemispheric speech lateralization and handedness has focused on individuals with speech and language disorders, such as dyslexia or specific language impairment (SLI). Such work reveals atypical patterns of cerebral lateralization and handedness in these groups compared to controls. There are few studies that examine this relationship in people with motor coordination impairments but without speech or reading deficits, which is a surprising omission given the prevalence of theories suggesting a common neural network underlying both functions. We use an emerging imaging technique in cognitive neuroscience; functional transcranial Doppler (fTCD) ultrasound, to assess whether individuals with developmental coordination disorder (DCD) display reduced left-hemisphere lateralization for speech production compared to control participants. Twelve adult control participants and 12 adults with DCD, but no other developmental/cognitive impairments, performed a word-generation task whilst undergoing fTCD imaging to establish a hemispheric lateralization index for speech production. All participants also completed an electronic peg-moving task to determine hand skill. As predicted, the DCD group showed a significantly reduced left lateralization pattern for the speech production task compared to controls. Performance on the motor skill task showed a clear preference for the dominant hand across both groups; however, the DCD group mean movement times were significantly higher for the non-dominant hand. This is the first study of its kind to assess hand skill and speech lateralization in DCD. The results reveal a reduced leftwards asymmetry for speech and a slower motor performance. This fits alongside previous work showing atypical cerebral lateralization in DCD for other cognitive processes (e.g., executive function and short-term memory) and thus speaks to debates on theories of the links between motor

Patterns of coordinated cortical remodeling during adolescence and their associations with functional specialization and evolutionary expansion.

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Sotiras, Aristeidis; Toledo, Jon B; Gur, Raquel E; Gur, Ruben C; Satterthwaite, Theodore D; Davatzikos, Christos

2017-03-28

During adolescence, the human cortex undergoes substantial remodeling to support a rapid expansion of behavioral repertoire. Accurately quantifying these changes is a prerequisite for understanding normal brain development, as well as the neuropsychiatric disorders that emerge in this vulnerable period. Past accounts have demonstrated substantial regional heterogeneity in patterns of brain development, but frequently have been limited by small samples and analytics that do not evaluate complex multivariate imaging patterns. Capitalizing on recent advances in multivariate analysis methods, we used nonnegative matrix factorization (NMF) to uncover coordinated patterns of cortical development in a sample of 934 youths ages 8-20, who completed structural neuroimaging as part of the Philadelphia Neurodevelopmental Cohort. Patterns of structural covariance (PSCs) derived by NMF were highly reproducible over a range of resolutions, and differed markedly from common gyral-based structural atlases. Moreover, PSCs were largely symmetric and showed correspondence to specific large-scale functional networks. The level of correspondence was ordered according to their functional role and position in the evolutionary hierarchy, being high in lower-order visual and somatomotor networks and diminishing in higher-order association cortex. Furthermore, PSCs showed divergent developmental associations, with PSCs in higher-order association cortex networks showing greater changes with age than primary somatomotor and visual networks. Critically, such developmental changes within PSCs were significantly associated with the degree of evolutionary cortical expansion. Together, our findings delineate a set of structural brain networks that undergo coordinated cortical thinning during adolescence, which is in part governed by evolutionary novelty and functional specialization.

The effect of hand position on perceived finger orientation in left- and right-handers.

Science.gov (United States)

Fraser, Lindsey E; Harris, Laurence R

2017-12-01

In the absence of visual feedback, the perceived orientation of the fingers is systematically biased. In right-handers these biases are asymmetrical between the left and right hands in the horizontal plane and may reflect common functional postures for the two hands. Here we compared finger orientation perception in right- and left-handed participants for both hands, across various hand positions in the horizontal plane. Participants rotated a white line on a screen optically superimposed over their hand to indicate the perceived position of the finger that was rotated to one of seven orientations with the hand either aligned with the body midline, aligned with the shoulder, or displaced by twice the shoulder-to-midline distance from the midline. We replicated the asymmetric pattern of biases previously reported in right-handed participants (left hand biased towards an orientation ~30° inward, right hand ~10° inward). However, no such asymmetry was found for left-handers, suggesting left-handers may use different strategies when mapping proprioception to body or space coordinates and/or have less specialization of function between the hands. Both groups' responses rotated further outward as distance of the hand from the body midline increased, consistent with other research showing spatial orientation estimates diverge outward in the periphery. Finally, for right-handers, precision of responses was best when the hand was aligned with the shoulder compared to the other two conditions. These results highlight the unique role of hand dominance and hand position in perception of finger orientation, and provide insight into the proprioceptive position sense of the upper limbs.

Mechanisms of Left-Right Coordination in Mammalian Locomotor Pattern Generation Circuits: A Mathematical Modeling View

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Talpalar, Adolfo E.; Rybak, Ilya A.

2015-01-01

The locomotor gait in limbed animals is defined by the left-right leg coordination and locomotor speed. Coordination between left and right neural activities in the spinal cord controlling left and right legs is provided by commissural interneurons (CINs). Several CIN types have been genetically identified, including the excitatory V3 and excitatory and inhibitory V0 types. Recent studies demonstrated that genetic elimination of all V0 CINs caused switching from a normal left-right alternating activity to a left-right synchronized “hopping” pattern. Furthermore, ablation of only the inhibitory V0 CINs (V0D subtype) resulted in a lack of left-right alternation at low locomotor frequencies and retaining this alternation at high frequencies, whereas selective ablation of the excitatory V0 neurons (V0V subtype) maintained the left–right alternation at low frequencies and switched to a hopping pattern at high frequencies. To analyze these findings, we developed a simplified mathematical model of neural circuits consisting of four pacemaker neurons representing left and right, flexor and extensor rhythm-generating centers interacting via commissural pathways representing V3, V0D, and V0V CINs. The locomotor frequency was controlled by a parameter defining the excitation of neurons and commissural pathways mimicking the effects of N-methyl-D-aspartate on locomotor frequency in isolated rodent spinal cord preparations. The model demonstrated a typical left-right alternating pattern under control conditions, switching to a hopping activity at any frequency after removing both V0 connections, a synchronized pattern at low frequencies with alternation at high frequencies after removing only V0D connections, and an alternating pattern at low frequencies with hopping at high frequencies after removing only V0V connections. We used bifurcation theory and fast-slow decomposition methods to analyze network behavior in the above regimes and transitions between them. The model

Postural Coordination during Socio-motor Improvisation.

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Gueugnon, Mathieu; Salesse, Robin N; Coste, Alexandre; Zhao, Zhong; Bardy, Benoît G; Marin, Ludovic

2016-01-01

Human interaction often relies on socio-motor improvisation. Creating unprepared movements during social interaction is not a random process but relies on rules of synchronization. These situations do not only involve people to be coordinated, but also require the adjustment of their posture in order to maintain balance and support movements. The present study investigated posture in such a context. More precisely, we first evaluated the impact of amplitude and complexity of arm movements on posture in solo situation. Then, we assessed the impact of interpersonal coordination on posture using the mirror game in which dyads performed improvised and synchronized movements (i.e., duo situation). Posture was measured through ankle-hip coordination in medio-lateral and antero-posterior directions (ML and AP respectively). Our results revealed the spontaneous emergence of in-phase pattern in ML direction and antiphase pattern in AP direction for solo and duo situations. These two patterns respectively refer to the simultaneous flexion/extension of the ankles and the hips in the same or opposite direction. It suggests different functional roles of postural coordination patterns in each direction, with in-phase supporting task performance in ML (dynamical stability) and antiphase supporting postural control in AP (mechanical stability). Although amplitude of movement did not influence posture, movement complexity disturbed postural stability in both directions. Conversely, interpersonal coordination promoted postural stability in ML but not in AP direction. These results are discussed in terms of the difference in coupling strength between ankle-hip coordination and interpersonal coordination.

Postural coordination during socio-motor improvisation

Directory of Open Access Journals (Sweden)

Mathieu Gueugnon

2016-08-01

Full Text Available Human interaction often relies on socio-motor improvisation. Creating unprepared movements during social interaction is not a random process but relies on rules of synchronization. These situations do not only involve people to be coordinated, but also require the adjustment of their posture in order to maintain balance and support movements. The present study investigated posture in such a context. More precisely, we first evaluated the impact of amplitude and complexity of arm movements on posture in solo situation. Then, we assessed the impact of interpersonal coordination on posture using the mirror game in which dyads performed improvised and synchronized movements (i.e., duo situation. Posture was measured through ankle-hip coordination in medio-lateral and antero-posterior directions (ML and AP respectively. Our results revealed the spontaneous emergence of in-phase pattern in ML direction and anti-phase pattern in AP direction for solo and duo situations. These two patterns respectively refer to the simultaneous flexion/extension of the ankles and the hips in the same or opposite direction. It suggests different functional roles of postural coordination patterns in each direction, with in-phase supporting task performance in ML (dynamical stability and antiphase supporting postural control in AP (mechanical stability. Although amplitude of movement did not influence posture, movement complexity disturbed postural stability in both directions. Conversely, interpersonal coordination promoted postural stability in ML but not in AP direction. These results are discussed in terms of the difference in coupling strength between ankle-hip coordination and interpersonal coordination.

A Prosthetic Hand Body Area Controller Based on Efficient Pattern Recognition Control Strategies.

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Benatti, Simone; Milosevic, Bojan; Farella, Elisabetta; Gruppioni, Emanuele; Benini, Luca

2017-04-15

Poliarticulated prosthetic hands represent a powerful tool to restore functionality and improve quality of life for upper limb amputees. Such devices offer, on the same wearable node, sensing and actuation capabilities, which are not equally supported by natural interaction and control strategies. The control in state-of-the-art solutions is still performed mainly through complex encoding of gestures in bursts of contractions of the residual forearm muscles, resulting in a non-intuitive Human-Machine Interface (HMI). Recent research efforts explore the use of myoelectric gesture recognition for innovative interaction solutions, however there persists a considerable gap between research evaluation and implementation into successful complete systems. In this paper, we present the design of a wearable prosthetic hand controller, based on intuitive gesture recognition and a custom control strategy. The wearable node directly actuates a poliarticulated hand and wirelessly interacts with a personal gateway (i.e., a smartphone) for the training and personalization of the recognition algorithm. Through the whole system development, we address the challenge of integrating an efficient embedded gesture classifier with a control strategy tailored for an intuitive interaction between the user and the prosthesis. We demonstrate that this combined approach outperforms systems based on mere pattern recognition, since they target the accuracy of a classification algorithm rather than the control of a gesture. The system was fully implemented, tested on healthy and amputee subjects and compared against benchmark repositories. The proposed approach achieves an error rate of 1.6% in the end-to-end real time control of commonly used hand gestures, while complying with the power and performance budget of a low-cost microcontroller.

Control model for dampening hand vibrations using information of internal and external coordinates.

Directory of Open Access Journals (Sweden)

Shunta Togo

Full Text Available In the present study, we investigate a control mechanism that dampens hand vibrations. Here, we propose a control method with two components to suppress hand vibrations. The first is a passive suppression method that lowers the joint stiffness to passively dampen the hand vibrations. The second is an active suppression method that adjusts an equilibrium point based on skyhook control to actively dampen the hand vibrations. In a simulation experiment, we applied these two methods to dampen hand vibrations during the shoulder's horizontal oscillation. We also conducted a measurement experiment wherein a subject's shoulder was sinusoidally oscillated by a platform that generated horizontal oscillations. The results of the measurement experiments showed that the jerk of each part of the arm in a task using a cup filled with water was smaller than the shoulder jerk and that in a task with a cup filled with stones was larger than the shoulder jerk. Moreover, the amplitude of the hand trajectory in both horizontal and vertical directions was smaller in a task using a cup filled with water than in a task using a cup filled with stones. The results of the measurement experiments were accurately reproduced by the active suppression method based on skyhook control. These results suggest that humans dampen hand vibrations by controlling the equilibrium point through the information of the external workspace and the internal body state rather than by lowering joint stiffness only by using internal information.

Distributed Coordination of Household Electricity Consumption

DEFF Research Database (Denmark)

Juelsgaard, Morten; Teixeira, Andre; Johansson, Mikael

2014-01-01

This work presents a distributed framework for coordination of flexible electricity consumption for a number of households in the distribution grid. We conduct coordination with the purpose of minimizing a trade-off between individual concerns about discomfort and electricity cost, on the one hand......, and joint concerns about grid losses and voltage variations on the other. Our contribution is mainly to illustrate how to conduct distributed coordination when consumers are jointly coupled by grid losses and voltage variations. In addition we illustrate the benefit of including consumption management...... in the grid operation, and how different types of consumption may present various benefits....

Transformation procedures in 3D terrestrial coordinate systems

Directory of Open Access Journals (Sweden)

Sedlák Vladimír

2001-12-01

Full Text Available Transformation procedures belong to the main tasks of surveyor working in a field of geodesy, for example in satellite geodesy or astronomical geodesy. It is necessary to know transformation procedures in 3D terrestrial (Earth coordinate systems. Increasingly a dynamic advance growth of application of satellite navigation systems, for example GPS (Global Positioning System into engineering surveying, real estate register and others spheres of applied geodesy and geo-surveying (mine surveying exacts knowledge of these transformation procedures between coordinates in various coordinate systems. These tasks are common for daily work for various practical surveyors too, not only for theoretical scientific working surveyors.Conventional Terrestrial System is 3D coordinate system what is the most important coordinate system in global geodesy. Conventional Terrestrial System is an approximation of the nature coordinate system of the Earth. The origin of this coordinate system is placed in the earth substantial centre of gravity and in the centre of geoid. Conventional Terrestrial System is the Cartesian right-handed coordinate system, i.e. positive one. The Local Astronomical System is 3D coordinate system too and it belongs to an important coordinate system in geodesy from its practical point of view. Many geodetic measurements are realized in this coordinate system. Designation of this coordinate system as astronomical system expresses its sticking to a normal line to an equipotential plane, i.e. to a vertical. Local Astronomical system is the left-handed cartesian coordinate system.Transformation procedures in 3D terrestrial coordinate systems with theory of these systems are presented in the paper. Transformation in the local astronomical coordinate system presents common transformation in a frame of an adjustment of various local geodetic networks. In a case of satellite measurements (GPS, satellite altimetry, etc. transformation between local and

Adaptive leg coordination with a biologically inspired neurocontroller

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Braught, Grant; Thomopoulos, Stelios C.

1996-10-01

Natural selection is responsible for the creation of robust and adaptive control systems. Nature's control systems are created only from primitive building blocks. Using insect neurophysiology as a guide, a neural architecture for leg coordination in a hexapod robot has been developed. Reflex chains and sensory feedback mechanisms from various insects and crustacea form the basis of a pattern generator for intra-leg coordination. The pattern generator contains neural oscillators which learn from sensory feedback to produce stepping patterns. Using sensory feedback as the source of learning information allows the pattern generator to adapt to changes in the leg dynamics due to internal or external causes. A coupling between six of the single leg pattern generators is used to produce the inter-leg coordination necessary to establish stable gaits.

Force coordination in static manipulation tasks performed using standard and non-standard grasping techniques.

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de Freitas, Paulo B; Jaric, Slobodan

2009-04-01

We evaluated coordination of the hand grip force (GF; normal component of the force acting at the hand-object contact area) and load force (LF; the tangential component) in a variety of grasping techniques and two LF directions. Thirteen participants exerted a continuous sinusoidal LF pattern against externally fixed handles applying both standard (i.e., using either the tips of the digits or the palms; the precision and palm grasps, respectively) and non-standard grasping techniques (using wrists and the dorsal finger areas; the wrist and fist grasp). We hypothesized (1) that the non-standard grasping techniques would provide deteriorated indices of force coordination when compared with the standard ones, and (2) that the nervous system would be able to adjust GF to the differences in friction coefficients of various skin areas used for grasping. However, most of the indices of force coordination remained similar across the tested grasping techniques, while the GF adjustments for the differences in friction coefficients (highest in the palm and the lowest in the fist and wrist grasp) provided inconclusive results. As hypothesized, GF relative to the skin friction was lowest in the precision grasp, but highest in the palm grasp. Therefore, we conclude that (1) the elaborate coordination of GF and LF consistently seen across the standard grasping techniques could be generalized to the non-standard ones, while (2) the ability to adjust GF using the same grasping technique to the differences in friction of various objects cannot be fully generalized to the GF adjustment when different grasps (i.e., hand segments) are used to manipulate the same object. Due to the importance of the studied phenomena for understanding both the functional and neural control aspects of manipulation, future studies should extend the current research to the transient and dynamic tasks, as well as to the general role of friction in our mechanical interactions with the environment.

Effects of handedness (left vs right) and cannabis abuse on intermanual coordination and negative symptoms in schizophrenic patients of the paranoid type.

Science.gov (United States)

Gorynia, Inge; Schwaiger, Markus

2011-09-01

Intermanual coordination as an index of interhemispheric transfer and negative symptoms were investigated in 50 left- and 42 right-handed schizophrenic inpatients of the paranoid type, also including drug abusers. The primary objective was to show that there were higher values in intermanual coordination and fewer manifestations of negative symptoms in the left-handed compared to the right-handed patients. This assumption was based on previous studies. Most importantly, right- and left-handed patients showed a different behaviour in intermanual coordination, when the duration of illness was taken into consideration. Thus, long-term left-handed paranoid patients performed better in intermanual coordination and showed fewer manifestations of negative symptoms than did long-term right-handed patients. These results were true for the large group of all patients, and among them for the subgroup of patients without drug abuse. Consequently, higher scores in intermanual coordination in left-handed patients may be related to a better interhemispheric crosstalk resulting in less pronounced negative symptoms. Secondary objectives assessed by explorative data analysis included the effects of cannabis abuse. While cannabis abuse may be more prevalent in left-handed patients, its effects may be more pronounced in right-handed patients, scoring higher in intermanual coordination and lower in manifestations of negative symptoms.

Coordination of Reach-to-Grasp Kinematics in Individuals With Childhood-Onset Dystonia Due to Hemiplegic Cerebral Palsy.

Science.gov (United States)

Kukke, Sahana N; Curatalo, Lindsey A; de Campos, Ana Carolina; Hallett, Mark; Alter, Katharine E; Damiano, Diane L

2016-05-01

Functional reaching is impaired in dystonia. Here, we analyze upper extremity kinematics to quantify timing and coordination abnormalities during unimanual reach-to-grasp movements in individuals with childhood-onset unilateral wrist dystonia. Kinematics were measured during movements of both upper limbs in a patient group ( n = 11, age = 17.5 ±5 years), and a typically developing control group ( n = 9, age = 16.6 ±5 years). Hand aperture was computed to study the coordination of reach and grasp. Time-varying joint synergies within one upper limb were calculated using a novel technique based on principal component analysis to study intra-limb coordination. In the non-dominant arm, results indicate reduced coordination between reach and grasp in patients who could not lift the grasped object compared to those who could lift it. Lifters exhibit incoordination in distal upper extremity joints later in the movement and non-lifters lacked coordination throughout the movement and in the whole upper limb. The amount of atypical coordination correlates with dystonia severity in patients. Reduced coordination during movement may reflect deficits in the execution of simultaneous movements, motor planning, or muscle activation. Rehabilitation efforts can focus on particular time points when kinematic patterns deviate abnormally to improve functional reaching in individuals with childhood-onset dystonia.

Hand Grasping Synergies As Biometrics.

Science.gov (United States)

Patel, Vrajeshri; Thukral, Poojita; Burns, Martin K; Florescu, Ionut; Chandramouli, Rajarathnam; Vinjamuri, Ramana

2017-01-01

Recently, the need for more secure identity verification systems has driven researchers to explore other sources of biometrics. This includes iris patterns, palm print, hand geometry, facial recognition, and movement patterns (hand motion, gait, and eye movements). Identity verification systems may benefit from the complexity of human movement that integrates multiple levels of control (neural, muscular, and kinematic). Using principal component analysis, we extracted spatiotemporal hand synergies (movement synergies) from an object grasping dataset to explore their use as a potential biometric. These movement synergies are in the form of joint angular velocity profiles of 10 joints. We explored the effect of joint type, digit, number of objects, and grasp type. In its best configuration, movement synergies achieved an equal error rate of 8.19%. While movement synergies can be integrated into an identity verification system with motion capture ability, we also explored a camera-ready version of hand synergies-postural synergies. In this proof of concept system, postural synergies performed well, but only when specific postures were chosen. Based on these results, hand synergies show promise as a potential biometric that can be combined with other hand-based biometrics for improved security.

Hand Grasping Synergies As Biometrics

Directory of Open Access Journals (Sweden)

Ramana Vinjamuri

2017-05-01

Full Text Available Recently, the need for more secure identity verification systems has driven researchers to explore other sources of biometrics. This includes iris patterns, palm print, hand geometry, facial recognition, and movement patterns (hand motion, gait, and eye movements. Identity verification systems may benefit from the complexity of human movement that integrates multiple levels of control (neural, muscular, and kinematic. Using principal component analysis, we extracted spatiotemporal hand synergies (movement synergies from an object grasping dataset to explore their use as a potential biometric. These movement synergies are in the form of joint angular velocity profiles of 10 joints. We explored the effect of joint type, digit, number of objects, and grasp type. In its best configuration, movement synergies achieved an equal error rate of 8.19%. While movement synergies can be integrated into an identity verification system with motion capture ability, we also explored a camera-ready version of hand synergies—postural synergies. In this proof of concept system, postural synergies performed well, but only when specific postures were chosen. Based on these results, hand synergies show promise as a potential biometric that can be combined with other hand-based biometrics for improved security.

Multiciliated cell basal bodies align in stereotypical patterns coordinated by the apical cytoskeleton

Science.gov (United States)

Herawati, Elisa; Kanoh, Hatsuho

2016-01-01

Multiciliated cells (MCCs) promote fluid flow through coordinated ciliary beating, which requires properly organized basal bodies (BBs). Airway MCCs have large numbers of BBs, which are uniformly oriented and, as we show here, align linearly. The mechanism for BB alignment is unexplored. To study this mechanism, we developed a long-term and high-resolution live-imaging system and used it to observe green fluorescent protein–centrin2–labeled BBs in cultured mouse tracheal MCCs. During MCC differentiation, the BB array adopted four stereotypical patterns, from a clustering “floret” pattern to the linear “alignment.” This alignment process was correlated with BB orientations, revealed by double immunostaining for BBs and their asymmetrically associated basal feet (BF). The BB alignment was disrupted by disturbing apical microtubules with nocodazole and by a BF-depleting Odf2 mutation. We constructed a theoretical model, which indicated that the apical cytoskeleton, acting like a viscoelastic fluid, provides a self-organizing mechanism in tracheal MCCs to align BBs linearly for mucociliary transport. PMID:27573463

Patterns of muscle activity underlying object-specific grasp by the macaque monkey.

Science.gov (United States)

Brochier, T; Spinks, R L; Umilta, M A; Lemon, R N

2004-09-01

During object grasp, a coordinated activation of distal muscles is required to shape the hand in relation to the physical properties of the object. Despite the fundamental importance of the grasping action, little is known of the muscular activation patterns that allow objects of different sizes and shapes to be grasped. In a study of two adult macaque monkeys, we investigated whether we could distinguish between EMG activation patterns associated with grasp of 12 differently shaped objects, chosen to evoke a wide range of grasping postures. Each object was mounted on a horizontal shuttle held by a weak spring (load force 1-2 N). Objects were located in separate sectors of a "carousel," and inter-trial rotation of the carousel allowed sequential presentation of the objects in pseudorandom order. EMG activity from 10 to 12 digit, hand, and arm muscles was recorded using chronically implanted electrodes. We show that the grasp of different objects was characterized by complex but distinctive patterns of EMG activation. Cluster analysis shows that these object-related EMG patterns were specific and consistent enough to identify the object unequivocally from the EMG recordings alone. EMG-based object identification required a minimum of six EMGs from simultaneously recorded muscles. EMG patterns were consistent across recording sessions in a given monkey but showed some differences between animals. These results identify the specific patterns of activity required to achieve distinct hand postures for grasping, and they open the way to our understanding of how these patterns are generated by the central motor network.

A natural approach to convey numerical digits using hand activity recognition based on hand shape features

Science.gov (United States)

Chidananda, H.; Reddy, T. Hanumantha

2017-06-01

This paper presents a natural representation of numerical digit(s) using hand activity analysis based on number of fingers out stretched for each numerical digit in sequence extracted from a video. The analysis is based on determining a set of six features from a hand image. The most important features used from each frame in a video are the first fingertip from top, palm-line, palm-center, valley points between the fingers exists above the palm-line. Using this work user can convey any number of numerical digits using right or left or both the hands naturally in a video. Each numerical digit ranges from 0 to9. Hands (right/left/both) used to convey digits can be recognized accurately using the valley points and with this recognition whether the user is a right / left handed person in practice can be analyzed. In this work, first the hand(s) and face parts are detected by using YCbCr color space and face part is removed by using ellipse based method. Then, the hand(s) are analyzed to recognize the activity that represents a series of numerical digits in a video. This work uses pixel continuity algorithm using 2D coordinate geometry system and does not use regular use of calculus, contours, convex hull and datasets.

Synthesis, structure, and electrochemistry and magnetic properties of a novel 1D homochiral MnIII(5-Brsalen) coordination polymer with left-handed helical character

Science.gov (United States)

Dong, Dapeng; Yu, Naisen; Zhao, Haiyan; Liu, Dedi; Liu, Jia; Li, Zhenghua; Liu, Dongping

2016-01-01

A novel homochiral manganese (III) Mn(5-Brsalen) coordination polymer with left-handed helical character by spontaneous resolution on crystallization by using Mn(5-Brsalen) and 4,4-bipyridine, [MnIII(5-Brsalen)(4,4-bipy)]·ClO4·CH3OH (1) (4,4-bipy = 4,4-bipyridine) has been synthesized and structurally characterized by X-ray single-crystal diffraction, elemental analysis and infrared spectroscopy. In compound 1, each manganese(III) anion is six-coordinate octahedral being bonded to four atoms of 5-Brsalen ligand in an equatorial plane and two nitrogen atoms from a 4,4-bipyridine ligand in axial positions. The structure of compound 1 can be described a supramolecular 2D-like structure which was formed by the intermolecular π-stacking interactions between the neighboring chains of the aromatic rings of 4,4-bipyridine and 5-Brsalen molecules. UV-vis absorption spectrum, electrochemistry and magnetic properties of the compound 1 have also been studied.

Hand dominance and age have interactive effects on motor cortical representations.

Directory of Open Access Journals (Sweden)

Jessica A Bernard

Full Text Available Older adults exhibit more bilateral motor cortical activity during unimanual task performance than young adults. Interestingly, a similar pattern is seen in young adults with reduced hand dominance. However, older adults report stronger hand dominance than young adults, making it unclear how handedness is manifested in the aging motor cortex. Here, we investigated age differences in the relationships between handedness, motor cortical organization, and interhemispheric communication speed. We hypothesized that relationships between these variables would differ for young and older adults, consistent with our recent proposal of an age-related shift in interhemispheric interactions. We mapped motor cortical representations of the right and left first dorsal interosseous muscles using transcranial magnetic stimulation (TMS in young and older adults recruited to represent a broad range of the handedness spectrum. We also measured interhemispheric communication speed and bimanual coordination. We observed that more strongly handed older adults exhibited more ipsilateral motor activity in response to TMS; this effect was not present in young adults. Furthermore, we found opposing relationships between interhemispheric communication speed and bimanual performance in the two age groups. Thus, handedness manifests itself differently in the motor cortices of young and older adults and has interactive effects with age.

Classification of brain signals associated with imagination of hand grasping, opening and reaching by means of wavelet-based common spatial pattern and mutual information.

Science.gov (United States)

Amanpour, Behzad; Erfanian, Abbas

2013-01-01

An important issue in designing a practical brain-computer interface (BCI) is the selection of mental tasks to be imagined. Different types of mental tasks have been used in BCI including left, right, foot, and tongue motor imageries. However, the mental tasks are different from the actions to be controlled by the BCI. It is desirable to select a mental task to be consistent with the desired action to be performed by BCI. In this paper, we investigated the detecting the imagination of the hand grasping, hand opening, and hand reaching in one hand using electroencephalographic (EEG) signals. The results show that the ERD/ERS patterns, associated with the imagination of hand grasping, opening, and reaching are different. For classification of brain signals associated with these mental tasks and feature extraction, a method based on wavelet packet, regularized common spatial pattern (CSP), and mutual information is proposed. The results of an offline analysis on five subjects show that the two-class mental tasks can be classified with an average accuracy of 77.6% using proposed method. In addition, we examine the proposed method on datasets IVa from BCI Competition III and IIa from BCI Competition IV.

Right-handed fossil humans.

Science.gov (United States)

Lozano, Marina; Estalrrich, Almudena; Bondioli, Luca; Fiore, Ivana; Bermúdez de Castro, José-Maria; Arsuaga, Juan Luis; Carbonell, Eudald; Rosas, Antonio; Frayer, David W

2017-11-01

Fossil hominids often processed material held between their upper and lower teeth. Pulling with one hand and cutting with the other, they occasionally left impact cut marks on the lip (labial) surface of their incisors and canines. From these actions, it possible to determine the dominant hand used. The frequency of these oblique striations in an array of fossil hominins documents the typically modern pattern of 9 right- to 1 left-hander. This ratio among living Homo sapiens differs from that among chimpanzees and bonobos and more distant primate relatives. Together, all studies of living people affirm that dominant right-handedness is a uniquely modern human trait. The same pattern extends deep into our past. Thus far, the majority of inferred right-handed fossils come from Europe, but a single maxilla from a Homo habilis, OH-65, shows a predominance of right oblique scratches, thus extending right-handedness into the early Pleistocene of Africa. Other studies show right-handedness in more recent African, Chinese, and Levantine fossils, but the sample compiled for non-European fossil specimens remains small. Fossil specimens from Sima del los Huesos and a variety of European Neandertal sites are predominately right-handed. We argue the 9:1 handedness ratio in Neandertals and the earlier inhabitants of Europe constitutes evidence for a modern pattern of handedness well before the appearance of modern Homo sapiens. © 2017 Wiley Periodicals, Inc.

Vertical jump fatigue does not affect intersegmental coordination and segmental contribution

Directory of Open Access Journals (Sweden)

Gleber Pereira

2014-09-01

Full Text Available The aim of this study was to describe the intersegmental coordination and segmental contribution during intermittent vertical jumps performed until fatigue. Seven male visited the laboratory on two occasions: 1 the maximum vertical jump height was determined followed by vertical jumps habituation; 2 participants performed intermittent countermovement jumps until fatigue. Kinematic and kinetic variables were recorded. The overall reduction in vertical jump height was 5,5%, while the movement duration increased 10% during the test. The thigh segment angle at movement reversal significantly increased as the exercise progressed. Non-significant effect of fatigue on movement synergy was found for the intersegmental coordination pattern. More than 90% of the intersegmental coordination was explained by one coordination pattern. Thigh rotation contributed the most to the intersegmental coordination pattern, with the trunk second and the shank the least. Therefore, one intersegmental coordination pattern is followed throughout the vertical jumps until fatigue and thigh rotation contributes the most to jump height.

Role of Gaze Cues in Interpersonal Motor Coordination: Towards Higher Affiliation in Human-Robot Interaction.

Directory of Open Access Journals (Sweden)

Mahdi Khoramshahi

Full Text Available The ability to follow one another's gaze plays an important role in our social cognition; especially when we synchronously perform tasks together. We investigate how gaze cues can improve performance in a simple coordination task (i.e., the mirror game, whereby two players mirror each other's hand motions. In this game, each player is either a leader or follower. To study the effect of gaze in a systematic manner, the leader's role is played by a robotic avatar. We contrast two conditions, in which the avatar provides or not explicit gaze cues that indicate the next location of its hand. Specifically, we investigated (a whether participants are able to exploit these gaze cues to improve their coordination, (b how gaze cues affect action prediction and temporal coordination, and (c whether introducing active gaze behavior for avatars makes them more realistic and human-like (from the user point of view.43 subjects participated in 8 trials of the mirror game. Each subject performed the game in the two conditions (with and without gaze cues. In this within-subject study, the order of the conditions was randomized across participants, and subjective assessment of the avatar's realism was assessed by administering a post-hoc questionnaire. When gaze cues were provided, a quantitative assessment of synchrony between participants and the avatar revealed a significant improvement in subject reaction-time (RT. This confirms our hypothesis that gaze cues improve the follower's ability to predict the avatar's action. An analysis of the pattern of frequency across the two players' hand movements reveals that the gaze cues improve the overall temporal coordination across the two players. Finally, analysis of the subjective evaluations from the questionnaires reveals that, in the presence of gaze cues, participants found it not only more human-like/realistic, but also easier to interact with the avatar.This work confirms that people can exploit gaze cues to

Study on portable optical 3D coordinate measuring system

Science.gov (United States)

Ren, Tongqun; Zhu, Jigui; Guo, Yinbiao

2009-05-01

A portable optical 3D coordinate measuring system based on digital Close Range Photogrammetry (CRP) technology and binocular stereo vision theory is researched. Three ultra-red LED with high stability is set on a hand-hold target to provide measuring feature and establish target coordinate system. Ray intersection based field directional calibrating is done for the intersectant binocular measurement system composed of two cameras by a reference ruler. The hand-hold target controlled by Bluetooth wireless communication is free moved to implement contact measurement. The position of ceramic contact ball is pre-calibrated accurately. The coordinates of target feature points are obtained by binocular stereo vision model from the stereo images pair taken by cameras. Combining radius compensation for contact ball and residual error correction, object point can be resolved by transfer of axes using target coordinate system as intermediary. This system is suitable for on-field large-scale measurement because of its excellent portability, high precision, wide measuring volume, great adaptability and satisfying automatization. It is tested that the measuring precision is near to +/-0.1mm/m.

Iterative solution of the Grad-Shafranov equation in symmetric magnetic coordinates

International Nuclear Information System (INIS)

Brambilla, Marco

2003-01-01

The inverse Grad-Shafranov equation for axisymmetric magnetohydrodynamic equilibria is reformulated in symmetric magnetic coordinates (in which magnetic field lines look 'straight', and the geometric toroidal angle is one of the coordinates). The poloidally averaged part of the equilibrium condition and Ampere law takes the form of two first-order ordinary differential equations, with the two arbitrary flux functions, pressure and force-free part of the current density, as sources. The condition for the coordinates to be flux coordinates, and the poloidally varying part of the equilibrium equation are similarly transformed into a set of first-order ordinary differential equations, with coefficients depending on the metric, and explicitly solved for the radial derivatives of the coefficients of the Fourier representation of the Cartesian coordinates in the poloidal angle. The derivation exploits the existence of Boozer-White coordinates, but does not require to find these coordinates explicitly; on the other hand, it offers a simple recipe to perform the transformation to Boozer-White coordinates, if required. Use of symmetric flux coordinates is advantageous for the formulation of many problems of equilibrium, stability, and wave propagation in tokamak plasmas, since these coordinates have the simplest metric of their class. It is also shown that in symmetric flux coordinates the Lagrangian equations of the drift motion of charged particles are automatically solved for the time derivatives, with right-hand sides closely related to the coefficients of the inverse Grad-Shafranov equation

Muscle recruitment and coordination with an ankle exoskeleton.

Science.gov (United States)

Steele, Katherine M; Jackson, Rachel W; Shuman, Benjamin R; Collins, Steven H

2017-07-05

Exoskeletons have the potential to assist and augment human performance. Understanding how users adapt their movement and neuromuscular control in response to external assistance is important to inform the design of these devices. The aim of this research was to evaluate changes in muscle recruitment and coordination for ten unimpaired individuals walking with an ankle exoskeleton. We evaluated changes in the activity of individual muscles, cocontraction levels, and synergistic patterns of muscle coordination with increasing exoskeleton work and torque. Participants were able to selectively reduce activity of the ankle plantarflexors with increasing exoskeleton assistance. Increasing exoskeleton net work resulted in greater reductions in muscle activity than increasing exoskeleton torque. Patterns of muscle coordination were not restricted or constrained to synergistic patterns observed during unassisted walking. While three synergies could describe nearly 95% of the variance in electromyography data during unassisted walking, these same synergies could describe only 85-90% of the variance in muscle activity while walking with the exoskeleton. Synergies calculated with the exoskeleton demonstrated greater changes in synergy weights with increasing exoskeleton work versus greater changes in synergy activations with increasing exoskeleton torque. These results support the theory that unimpaired individuals do not exclusively use central pattern generators or other low-level building blocks to coordinate muscle activity, especially when learning a new task or adapting to external assistance, and demonstrate the potential for using exoskeletons to modulate muscle recruitment and coordination patterns for rehabilitation or performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Evaluation of coordination and balance in preterm children].

Science.gov (United States)

Rodríguez Fernández, Cristina; Mata Zubillaga, Daniel; Rodríguez Fernández, Luis Miguel; Regueras Santos, Laura; Reguera García, Maria Mercedes; de Paz Fernández, José Antonio; Lapeña López de Armentia, Santiago

2016-08-01

Recent studies show that many preterm children without apparent neurological sequelae present some difficulties in different areas, such as coordination or balance during their school years. The Movement Assessment Battery for Children-2 (MABC-2) has demonstrated to be a useful tool to validate the coordination, while the stabilometric platform was the reference standard test for validating the balance. Case-control study carried out on preterm children from 7 to 10 years old and healthy term infant controls of the same ages. The same age band of MABC-2 was applied and the static balance by the stabilometric platform was analysed. A total of 89 subjects were included, 30 preterm children≤1,500g birthweight, 29 preterm children>1,500g birthweight, and 30 controls. Preterm children obtained the lowest scores on an overall basis in hand dexterity and balance tests in MABC-2, regardless of their birthweight. Lower gestational age was associated with poorer outcomes in hand dexterity and total scores in MABC-2. Balance results were similar using the stabilometric platform, regardless of prematurity. A little more than 10% preterm and term children could have coordination disorders or be at risk of developing them using the MABC-2. Despite the visual-motor coordination being similar, preterm children could face greater difficulties in hand dexterity while, in the absence of neurological comorbidity, preterm and term children balance could be comparable. Copyright © 2015 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

Intelligent, self-contained robotic hand

Science.gov (United States)

Krutik, Vitaliy; Doo, Burt; Townsend, William T.; Hauptman, Traveler; Crowell, Adam; Zenowich, Brian; Lawson, John

2007-01-30

A robotic device has a base and at least one finger having at least two links that are connected in series on rotary joints with at least two degrees of freedom. A brushless motor and an associated controller are located at each joint to produce a rotational movement of a link. Wires for electrical power and communication serially connect the controllers in a distributed control network. A network operating controller coordinates the operation of the network, including power distribution. At least one, but more typically two to five, wires interconnect all the controllers through one or more joints. Motor sensors and external world sensors monitor operating parameters of the robotic hand. The electrical signal output of the sensors can be input anywhere on the distributed control network. V-grooves on the robotic hand locate objects precisely and assist in gripping. The hand is sealed, immersible and has electrical connections through the rotary joints for anodizing in a single dunk without masking. In various forms, this intelligent, self-contained, dexterous hand, or combinations of such hands, can perform a wide variety of object gripping and manipulating tasks, as well as locomotion and combinations of locomotion and gripping.

Robotic set-up to quantify hand-eye behavior in motor execution and learning of children with autism spectrum disorder.

Science.gov (United States)

Casellato, Claudia; Gandolla, Marta; Crippa, Alessandro; Pedrocchi, Alessandra

2017-07-01

Autism spectrum disorder (ASD) is a multifaceted neurodevelopmental disorder characterized by a persistence of social and communication impairment, and restricted and repetitive behaviors. However, motor disorders have also been described, but not objectively assessed. Most studies showed inefficient eye-hand coordination and motor learning in children with ASD; in other experiments, mechanisms of acquisition of internal models in self-generated movements appeared to be normal in autism. In this framework, we have developed a robotic protocol, recording gaze and hand data during upper limb tasks, in which a haptic pen-like handle is moved along specific trajectories displayed on the screen. The protocol includes trials of reaching under a perturbing force field and catching moving targets, with or without visual availability of the whole path. We acquired 16 typically-developing scholar-age children and one child with ASD as a case study. Speed-accuracy tradeoff, motor performance, and gaze-hand spatial coordination have been evaluated. Compared to typically developing peers, in the force field sequence, the child with ASD showed an intact but delayed learning, and more variable gazehand patterns. In the catching trials, he showed less efficient movements, but an intact capability of exploiting the available a-priori plan. The proposed protocol represents a powerful tool, easily tunable, for quantitative (longitudinal) assessment, and for subject-tailored training in ASD.

Movement coordination in applied human-human and human-robot interaction

DEFF Research Database (Denmark)

Schubö, Anna; Vesper, Cordula; Wiesbeck, Mathey

2007-01-01

and describing human-human interaction in terms of goal-oriented movement coordination is considered an important and necessary step for designing and describing human-robot interaction. In the present scenario, trajectories of hand and finger movements were recorded while two human participants performed......The present paper describes a scenario for examining mechanisms of movement coordination in humans and robots. It is assumed that coordination can best be achieved when behavioral rules that shape movement execution in humans are also considered for human-robot interaction. Investigating...... coordination were affected. Implications for human-robot interaction are discussed....

Hand preferences for coordinated bimanual actions in 777 great apes

DEFF Research Database (Denmark)

Hopkins, William D; Phillips, Kimberley A; Bania, Amanda

2011-01-01

Whether or not nonhuman primates exhibit population-level handedness remains a topic of considerable scientific debate. Here, we examined handedness for coordinated bimanual actions in a sample of 777 great apes including chimpanzees, bonobos, gorillas, and orangutans. We found population......-level right-handedness in chimpanzees, bonobos and gorillas, but left-handedness in orangutans. Directional biases in handedness were consistent across independent samples of apes within each genus. We suggest that, contrary to previous claims, population-level handedness is evident in great apes but differs...

Age patterns and transmission characteristics of hand, foot and mouth disease in China

Directory of Open Access Journals (Sweden)

Jijun Zhao

2016-11-01

Full Text Available Abstract Background Hand, foot and mouth disease (HFMD has circulated in China and caused yearly outbreak. To understand the transmission of the disease and to assess the spatial variation in cases reported, we examined age-specific transmission characteristics and reporting rates of HFMD for 31 provinces in mainland China. Methods We first analyzed incidence spatial patterns and age-specific incidence patterns using dataset from 2008 to 2012. Transmission characteristics were estimated based on catalytic model. Reporting rates were estimated using a simple mass action model from “Time Series Susceptible Infectious Recovered” (TSIR modeling. Results We found age-specific spatial incidence patterns: age-specific proportions of HFMD cases varied geographically in China; larger case percentage was among children of 3–5 years old in the northern part of China and was among children of 0–2 years old in the southern part of China. Our analysis results revealed that: 1 reporting rates and transmission characteristics including the average age at infection, the force of infection and the basic reproduction number varied geographically in China; 2 patterns of the age-specific force of infection for 30 provinces were similar to that of childhood infections in developed countries; the age group that had the highest infection risk was 3–5 years old in 30 provinces, and 10–14 years old in Tibet; 3 a large difference in HFMD transmission existed between northwest region and southeast region; 4 transmission characteristics determined incidence patterns: the higher the disease transmission in a province, the earlier the annual seasonality started and the more case percentage was among children 0–2 years old and less among 3–5 years old. Conclusion Because HFMD has higher transmission than most childhood infections reported, high effective vaccine coverage is needed to substantially reduce HFMD incidence. Control measures before the vaccine

Specialization Patterns

OpenAIRE

Schultz , Ulrik Pagh; Lawall , Julia ,; Consel , Charles

1999-01-01

Design patterns offer numerous advantages for software development, but can introduce inefficiency into the finished program. Program specialization can eliminate such overheads, but is most effective when targeted by the user to specific bottlenecks. Consequently, we propose to consider program specialization and design patterns as complementary concepts. On the one hand, program specialization can optimize object-oriented programs written using design patterns. On the other hand, design pat...

Dreams: a framework for distributed synchronous coordination

NARCIS (Netherlands)

Proença, J.; Clarke, D.; Vink, de E.P.; Arbab, F.

2012-01-01

Synchronous coordination systems, such as Reo, exchange data via indivisible actions, while distributed systems are typically asynchronous and assume that messages can be delayed or get lost. To combine these seemingly contradictory notions, we introduce the Dreams framework. Coordination patterns

patterns of knee, hip and hand osteoarthritis in kenyatta national

African Journals Online (AJOL)

studied to determine the prevalence of obesity in this cohort of patients. Results: A total of 201 patients with knee, hip or hand osteoarthritis were studied. Of these participants,. 77% had knee OA, 15% hip OA, 3% hand OA and 5% had combined knee and hip OA. Obese participants were 41% and 32% were overweight.

Stability of Phase Relationships While Coordinating Arm Reaches with Whole Body Motion.

Directory of Open Access Journals (Sweden)

Romy S Bakker

Full Text Available The human movement repertoire is characterized by the smooth coordination of several body parts, including arm movements and whole body motion. The neural control of this coordination is quite complex because the various body parts have their own kinematic and dynamic properties. Behavioral inferences about the neural solution to the coordination problem could be obtained by examining the emerging phase relationship and its stability. Here, we studied the phase relationships that characterize the coordination of arm-reaching movements with passively-induced whole-body motion. Participants were laterally translated using a vestibular chair that oscillated at a fixed frequency of 0.83 Hz. They were instructed to reach between two targets that were aligned either parallel or orthogonal to the whole body motion. During the first cycles of body motion, a metronome entrained either an in-phase or an anti-phase relationship between hand and body motion, which was released at later cycles to test phase stability. Results suggest that inertial forces play an important role when coordinating reaches with cyclic whole-body motion. For parallel reaches, we found a stable in-phase and an unstable anti-phase relationship. When the latter was imposed, it readily transitioned or drifted back toward an in-phase relationship at cycles without metronomic entrainment. For orthogonal reaches, we did not find a clear difference in stability between in-phase and anti-phase relationships. Computer simulations further show that cost models that minimize energy expenditure (i.e. net torques or endpoint variance of the reach cannot fully explain the observed coordination patterns. We discuss how predictive control and impedance control processes could be considered important mechanisms underlying the rhythmic coordination of arm reaches and body motion.

Cross-organisational workflow management and co-ordination: WACC'99 workshop report

NARCIS (Netherlands)

Ludwig, Heiko; Bussler, Christoph; Shan, Ming-Chien; Grefen, P.W.P.J.

The increasing deployment of Workflow Management Systems (WfMSs) and other co-ordination and process support systems on the one hand and the proliferation of cheap networking, namely the Internet, on the other hand raises the issue of how to connect these systems across organisational boundaries.

Hands-off and hands-on casting consistency of amputee below knee sockets using magnetic resonance imaging.

Science.gov (United States)

Safari, Mohammad Reza; Rowe, Philip; McFadyen, Angus; Buis, Arjan

2013-01-01

Residual limb shape capturing (Casting) consistency has a great influence on the quality of socket fit. Magnetic Resonance Imaging was used to establish a reliable reference grid for intercast and intracast shape and volume consistency of two common casting methods, Hands-off and Hands-on. Residual limbs were cast for twelve people with a unilateral below knee amputation and scanned twice for each casting concept. Subsequently, all four volume images of each amputee were semiautomatically segmented and registered to a common coordinate system using the tibia and then the shape and volume differences were calculated. The results show that both casting methods have intra cast volume consistency and there is no significant volume difference between the two methods. Inter- and intracast mean volume differences were not clinically significant based on the volume of one sock criteria. Neither the Hands-off nor the Hands-on method resulted in a consistent residual limb shape as the coefficient of variation of shape differences was high. The resultant shape of the residual limb in the Hands-off casting was variable but the differences were not clinically significant. For the Hands-on casting, shape differences were equal to the maximum acceptable limit for a poor socket fit.

Coordinate transformations, orthographic projections, and robot kinematics

International Nuclear Information System (INIS)

Crochetiere, W.J.

1984-01-01

Humans do not consciously think of moving each of their joints while they move their hands from one place to another. Likewise, robot arms can be commanded to move about in cartesian space without the need to address the individual joints. To do this, the direct and inverse kinematic equations of any robot arm must be derived. The direct kinematic equations uniquely transform the joint positions into the position (and orientation) of the hand, whereas the inverse kinematic equations transform the position (and orientation) of the hand into joint positions. The derivation of the inverse kinematic equations for any particular robot is a difficult problem which may have more than one solution. In this paper, these equations are derived for a six degree of freedom robot arm. A combination of matrix operations to perform coordinate rotations, and trigonometry within the appropriate orthographic projects to perform coordinate translations is employed. This complementary approach yields a solution which is more easily obtained, and also more easily visualized. The resulting solution was programmed into a real-time computer as a part of a higher level software system to control the motion of the arm

Coordination strategies of crew management

Science.gov (United States)

Conley, Sharon; Cano, Yvonne; Bryant, Don

1991-01-01

An exploratory study that describes and contrasts two three-person flight crews performing in a B-727 simulator is presented. This study specifically attempts to delineate crew communication patterns accounting for measured differences in performance across routine and nonroutine flight patterns. The communication patterns in the two crews evaluated indicated different modes of coordination, i.e., standardization in the less effective crew and planning/mutual adjustment in the more effective crew.

Investigating the Constrained Action Hypothesis: A Movement Coordination and Coordination Variability Approach.

Science.gov (United States)

Vidal, Anthony; Wu, Will; Nakajima, Mimi; Becker, James

2017-09-19

The purpose of this study was to examine the effects of focus of attention cues on movement coordination and coordination variability in the lower extremity. Twenty participants performed the standing long jump under both internal and external focus of attention conditions. A modified vector coding technique was used to evaluate the influence of attentional focus cues on lower extremity coordination patterns and coordination variability during the jumps. Participants jumped significantly further under an external focus of attention condition compared with an internal focus of attention condition (p = .035, effect size = .29). Focus of attention also influenced coordination between the ankle and knee, F(6, 19) = 2.87, p = .012, effect size = .388, with participants primarily using their knees under the internal focus of attention, and using both their ankles and knees under the external focus of attention. Attentional focus cues did not influence ankle-knee, F(1, 19) = 0.02, p = .98, effect size = .02, or hip-knee, F(1, 19) = 5.00, p = .49, effect size = .16, coordination variability. Results suggest that while attentional focus may not directly influence movement coordination condition, there is still a change in movement strategy resulting in greater jump distances following an external focus of attention.

Coordinating controls

Energy Technology Data Exchange (ETDEWEB)

Anon.

1986-07-15

While physics Laboratories are having to absorb cuts in resources, the machines they rely on are becoming more and more complex, requiring increasingly sophisticated systems. Rather than being a resourceful engineer or physicist able to timber together solutions in his 'backyard', the modern controls specialist has become a professional in his own right. Because of possible conflicts between increasing sophistication on one hand and scarcer resources on the other, there was felt a need for more contacts among controls specialists to exchange experiences, coordinate development and discuss 'family problems', away from meetings where the main interest is on experimental physics.

Bundling hand hygiene interventions and measurement to decrease health care-associated infections.

Science.gov (United States)

Pincock, Ted; Bernstein, Paul; Warthman, Shawn; Holst, Elizabeth

2012-05-01

Proper performance of hand hygiene at key moments during patient care is the most important means of preventing health care-associated infections (HAIs). With increasing awareness of the cost and societal impact caused by HAIs has come the realization that hand hygiene improvement initiatives are crucial to reducing the burden of HAIs. Multimodal strategies have emerged as the best approach to improving hand hygiene compliance. These strategies use a variety of intervention components intended to address obstacles to complying with good hand hygiene practices, and to reinforce behavioral change. Although research has substantiated the effectiveness of the multimodal design, challenges remain in promoting widespread adoption and implementation of a coordinated approach. This article reviews elements of a multimodal approach to improve hand hygiene and advocates the use of a "bundled" strategy. Eight key components of this bundle are proposed as a cohesive program to enable the deployment of synergistic, coordinated efforts to promote good hand hygiene practice. A consistent, bundled methodology implemented at multiple study centers would standardize processes and allow comparison of outcomes, validation of the methodology, and benchmarking. Most important, a bundled approach can lead to sustained infection reduction. Copyright © 2012 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

The hot (invisible?) hand: can time sequence patterns of success/failure in sports be modeled as repeated random independent trials?

Science.gov (United States)

Yaari, Gur; Eisenmann, Shmuel

2011-01-01

The long lasting debate initiated by Gilovich, Vallone and Tversky in [Formula: see text] is revisited: does a "hot hand" phenomenon exist in sports? Hereby we come back to one of the cases analyzed by the original study, but with a much larger data set: all free throws taken during five regular seasons ([Formula: see text]) of the National Basketball Association (NBA). Evidence supporting the existence of the "hot hand" phenomenon is provided. However, while statistical traces of this phenomenon are observed in the data, an open question still remains: are these non random patterns a result of "success breeds success" and "failure breeds failure" mechanisms or simply "better" and "worse" periods? Although free throws data is not adequate to answer this question in a definite way, we speculate based on it, that the latter is the dominant cause behind the appearance of the "hot hand" phenomenon in the data.

Automated cross-modal mapping in robotic eye/hand systems using plastic radial basis function networks

Science.gov (United States)

Meng, Qinggang; Lee, M. H.

2007-03-01

Advanced autonomous artificial systems will need incremental learning and adaptive abilities similar to those seen in humans. Knowledge from biology, psychology and neuroscience is now inspiring new approaches for systems that have sensory-motor capabilities and operate in complex environments. Eye/hand coordination is an important cross-modal cognitive function, and is also typical of many of the other coordinations that must be involved in the control and operation of embodied intelligent systems. This paper examines a biologically inspired approach for incrementally constructing compact mapping networks for eye/hand coordination. We present a simplified node-decoupled extended Kalman filter for radial basis function networks, and compare this with other learning algorithms. An experimental system consisting of a robot arm and a pan-and-tilt head with a colour camera is used to produce results and test the algorithms in this paper. We also present three approaches for adapting to structural changes during eye/hand coordination tasks, and the robustness of the algorithms under noise are investigated. The learning and adaptation approaches in this paper have similarities with current ideas about neural growth in the brains of humans and animals during tool-use, and infants during early cognitive development.

Effect of hand-arm bimanual intensive therapy on fine-motor ...

African Journals Online (AJOL)

Manal Abd El Wahab

2014-09-04

Sep 4, 2014 ... a Department of Physical Therapy for Pediatrics, Faculty of Physical ... Abstract Children with hemiplegic cerebral palsy have impairments in bimanual coordination ..... vated during bimanual hand training that in turn leads to.

Different ankle muscle coordination patterns and co-activation during quiet stance between young adults and seniors do not change after a bout of high intensity training.

Science.gov (United States)

Donath, Lars; Kurz, Eduard; Roth, Ralf; Zahner, Lukas; Faude, Oliver

2015-03-04

Available evidence suggests that young adults and seniors use different strategies to adjust for increasing body sway during quiet standing. Altered antagonist muscle co-activation and different ankle muscle coordination patterns may account for this finding. Consequently, we aimed at addressing whether aging leads to changes in neuromuscular coordination patterns as well as co-activation during quiet stance. We additionally investigated whether a bout of high intensity interval training additionally alters these patterns. Twenty healthy seniors (age: 70 ± 4 y) and twenty young adults (age: 27 ± 3 y) were enrolled in the present study. In between the testing procedures, four consecutive high-intensity intervals of 4 min duration at a target exercise intensity of 90 to 95% HRmax were completed on a treadmill. The total center of pressure (COP) path length displacement served as standing balance performance outcome. In order to assess ankle muscle coordination patterns, amplitude ratios (AR) were calculated for each muscle (e.g. tibialis anterior (TA) [%] = (TA × 100)/(gastrocnemius medialis (GM) + soleus (SOL) + peroneus longus (PL) + TA). The co-activation was calculated for the SOL and TA muscles computing the co-activation index (CAI = 2 × TA/TA + SOL). Seniors showed an inverted ankle muscle coordination pattern during single limb stance with eyes open (SLEO), compared to young adults (rest: GM, S: 15 ± 8% vs Y: 24 ± 9%; p = 0.03; SOL, S: 27 ± 14% vs Y: 37 ± 18%; p = 0.009; TA, S: 31 ± 13% vs Y: 13 ± 7%; p = 0.003). These patterns did not change after a high-intensity training session. A moderate correlation between amplitude ratios of the TA-contribution and postural sway was observed for seniors during SLEO (r = 0.61). Ankle co-activation was twofold elevated in seniors compared to young adults during SLEO (p Seniors with decreased postural control showed higher TA

Hand Rehabilitation Learning System With an Exoskeleton Robotic Glove.

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Ma, Zhou; Ben-Tzvi, Pinhas; Danoff, Jerome

2016-12-01

This paper presents a hand rehabilitation learning system, the SAFE Glove, a device that can be utilized to enhance the rehabilitation of subjects with disabilities. This system is able to learn fingertip motion and force for grasping different objects and then record and analyze the common movements of hand function including grip and release patterns. The glove is then able to reproduce these movement patterns in playback fashion to assist a weakened hand to accomplish these movements, or to modulate the assistive level based on the user's or therapist's intent for the purpose of hand rehabilitation therapy. Preliminary data have been collected from healthy hands. To demonstrate the glove's ability to manipulate the hand, the glove has been fitted on a wooden hand and the grasping of various objects was performed. To further prove that hands can be safely driven by this haptic mechanism, force sensor readings placed between each finger and the mechanism are plotted. These experimental results demonstrate the potential of the proposed system in rehabilitation therapy.

Neural representation of hand kinematics during prehension in posterior parietal cortex of the macaque monkey.

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Chen, Jessie; Reitzen, Shari D; Kohlenstein, Jane B; Gardner, Esther P

2009-12-01

Studies of hand manipulation neurons in posterior parietal cortex of monkeys suggest that their spike trains represent objects by the hand postures needed for grasping or by the underlying patterns of muscle activation. To analyze the role of hand kinematics and object properties in a trained prehension task, we correlated the firing rates of neurons in anterior area 5 with hand behaviors as monkeys grasped and lifted knobs of different shapes and locations in the workspace. Trials were divided into four classes depending on the approach trajectory: forward, lateral, and local approaches, and regrasps. The task factors controlled by the animal-how and when he used the hand-appeared to play the principal roles in modulating firing rates of area 5 neurons. In all, 77% of neurons studied (58/75) showed significant effects of approach style on firing rates; 80% of the population responded at higher rates and for longer durations on forward or lateral approaches that included reaching, wrist rotation, and hand preshaping prior to contact, but only 13% distinguished the direction of reach. The higher firing rates in reach trials reflected not only the arm movements needed to direct the hand to the target before contact, but persisted through the contact, grasp, and lift stages. Moreover, the approach style exerted a stronger effect on firing rates than object features, such as shape and location, which were distinguished by half of the population. Forty-three percent of the neurons signaled both the object properties and the hand actions used to acquire them. However, the spread in firing rates evoked by each knob on reach and no-reach trials was greater than distinctions between different objects grasped with the same approach style. Our data provide clear evidence for synergies between reaching and grasping that may facilitate smooth, coordinated actions of the arm and hand.

The hot (invisible? hand: can time sequence patterns of success/failure in sports be modeled as repeated random independent trials?

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Gur Yaari

Full Text Available The long lasting debate initiated by Gilovich, Vallone and Tversky in [Formula: see text] is revisited: does a "hot hand" phenomenon exist in sports? Hereby we come back to one of the cases analyzed by the original study, but with a much larger data set: all free throws taken during five regular seasons ([Formula: see text] of the National Basketball Association (NBA. Evidence supporting the existence of the "hot hand" phenomenon is provided. However, while statistical traces of this phenomenon are observed in the data, an open question still remains: are these non random patterns a result of "success breeds success" and "failure breeds failure" mechanisms or simply "better" and "worse" periods? Although free throws data is not adequate to answer this question in a definite way, we speculate based on it, that the latter is the dominant cause behind the appearance of the "hot hand" phenomenon in the data.

Proprioceptive bimanual test in intrinsic and extrinsic coordinates.

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Iandolo, Riccardo; Squeri, Valentina; De Santis, Dalia; Giannoni, Psiche; Morasso, Pietro; Casadio, Maura

2015-01-01

Is there any difference between matching the position of the hands by asking the subjects to move them to the same spatial location or to mirror-symmetric locations with respect to the body midline? If the motion of the hands were planned in the extrinsic space, the mirror-symmetric task would imply an additional challenge, because we would need to flip the coordinates of the target on the other side of the workspace. Conversely, if the planning were done in intrinsic coordinates, in order to move both hands to the same spot in the workspace, we should compute different joint angles for each arm. Even if both representations were available to the subjects, the two tasks might lead to different results, providing some cue on the organization of the "body schema". In order to answer such questions, the middle fingertip of the non-dominant hand of a population of healthy subjects was passively moved by a manipulandum to 20 different target locations. Subjects matched these positions with the middle fingertip of their dominant hand. For most subjects, the matching accuracy was higher in the extrinsic modality both in terms of systematic error and variability, even for the target locations in which the configuration of the arms was the same for both modalities. This suggests that the matching performance of the subjects could be determined not only by proprioceptive information but also by the cognitive representation of the task: expressing the goal as reaching for the physical location of the hand in space is apparently more effective than requiring to match the proprioceptive representation of joint angles.

RELATIONS BETWEEN ANTHROPOMETRIC CHARACTERISTICS AND COORDINATION IN PEOPLE WITH ABOVE-AVERAGE MOTOR ABILITIES

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Milan Cvetković

2011-09-01

Full Text Available The sample of 149 male persons whose average age is 20.15 in decimal years (±0.83, and all of whom are students at the Faculty of Sport and Physical Education, underwent a battery of tests consisting of 17 anthropometric measures taken from the measures index of the International Biological Program and 4 tests designed to assess coordination as follows: Coordination with stick, Hand and leg drumming, Nonrhythmic drumming and Slalom with three balls. One statistically significant canonical correlation was determined by means of the canonical correlation analysis. The isolated canonical correlation from the space of coordination variables, was the one used for assessment of coordination of the whole body – Coordination with stick. On the other hand, out of the variables from the right array, the ones which covered longinality were singled out – Body height and Arm length, circular dimensionality – Circumference of stretched upper arm, Circumference of bent upper arm and Circumference of upper leg, as well as subcutaneous fat tissue – Skin fold of the back.

Development of a 3D immersive videogame to improve arm-postural coordination in patients with TBI

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Cassavaugh Nicholas D

2011-10-01

Full Text Available Abstract Background Traumatic brain injury (TBI disrupts the central and executive mechanisms of arm(s and postural (trunk and legs coordination. To address these issues, we developed a 3D immersive videogame-- Octopus. The game was developed using the basic principles of videogame design and previous experience of using videogames for rehabilitation of patients with acquired brain injuries. Unlike many other custom-designed virtual environments, Octopus included an actual gaming component with a system of multiple rewards, making the game challenging, competitive, motivating and fun. Effect of a short-term practice with the Octopus game on arm-postural coordination in patients with TBI was tested. Methods The game was developed using WorldViz Vizard software, integrated with the Qualysis system for motion analysis. Avatars of the participant's hands precisely reproducing the real-time kinematic patterns were synchronized with the simulated environment, presented in the first person 3D view on an 82-inch DLP screen. 13 individuals with mild-to-moderate manifestations of TBI participated in the study. While standing in front of the screen, the participants interacted with a computer-generated environment by popping bubbles blown by the Octopus. The bubbles followed a specific trajectory. Interception of the bubbles with the left or right hand avatar allowed flexible use of the postural segments for balance maintenance and arm transport. All participants practiced ten 90-s gaming trials during a single session, followed by a retention test. Arm-postural coordination was analysed using principal component analysis. Results As a result of the short-term practice, the participants improved in game performance, arm movement time, and precision. Improvements were achieved mostly by adapting efficient arm-postural coordination strategies. Of the 13 participants, 10 showed an immediate increase in arm forward reach and single-leg stance time. Conclusion

Development of a 3D immersive videogame to improve arm-postural coordination in patients with TBI.

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Ustinova, Ksenia I; Leonard, Wesley A; Cassavaugh, Nicholas D; Ingersoll, Christopher D

2011-10-31

Traumatic brain injury (TBI) disrupts the central and executive mechanisms of arm(s) and postural (trunk and legs) coordination. To address these issues, we developed a 3D immersive videogame--Octopus. The game was developed using the basic principles of videogame design and previous experience of using videogames for rehabilitation of patients with acquired brain injuries. Unlike many other custom-designed virtual environments, Octopus included an actual gaming component with a system of multiple rewards, making the game challenging, competitive, motivating and fun. Effect of a short-term practice with the Octopus game on arm-postural coordination in patients with TBI was tested. The game was developed using WorldViz Vizard software, integrated with the Qualysis system for motion analysis. Avatars of the participant's hands precisely reproducing the real-time kinematic patterns were synchronized with the simulated environment, presented in the first person 3D view on an 82-inch DLP screen. 13 individuals with mild-to-moderate manifestations of TBI participated in the study. While standing in front of the screen, the participants interacted with a computer-generated environment by popping bubbles blown by the Octopus. The bubbles followed a specific trajectory. Interception of the bubbles with the left or right hand avatar allowed flexible use of the postural segments for balance maintenance and arm transport. All participants practiced ten 90-s gaming trials during a single session, followed by a retention test. Arm-postural coordination was analysed using principal component analysis. As a result of the short-term practice, the participants improved in game performance, arm movement time, and precision. Improvements were achieved mostly by adapting efficient arm-postural coordination strategies. Of the 13 participants, 10 showed an immediate increase in arm forward reach and single-leg stance time. These results support the feasibility of using the custom-made 3D

The relationship between segmental coordination, agility and physical activity in adolescents

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Eliseo García Cantó

2015-06-01

Full Text Available Motor competence (MC may be related to youth physical activity (PA level. In the last few years, MC has been studied as a possible determinant of children PA level, but has not been widely studied in adolescents. To analyze the relationship between MC and PA level 533 adolescents (271 men and 261 women from the southeast of Spain were assessed. To register weekly PA was used the International Physical Activity Questionnaire (IPAQ and for the MC, four coordination tests including throw and catch test, eye-hand and eye-foot coordination tests and agility circuit. Data were analyzed using ANOVA and binary logistic regression. The overall MC is consistently related with PA level. Eye-hand coordination test and the agility test define more accurately the tendency to high PA level. Programs to promote PA and focused on MC should be emphasized from early ages to adolescence.

Coordinating controls

International Nuclear Information System (INIS)

Anon.

1986-01-01

While physics Laboratories are having to absorb cuts in resources, the machines they rely on are becoming more and more complex, requiring increasingly sophisticated systems. Rather than being a resourceful engineer or physicist able to timber together solutions in his 'backyard', the modern controls specialist has become a professional in his own right. Because of possible conflicts between increasing sophistication on one hand and scarcer resources on the other, there was felt a need for more contacts among controls specialists to exchange experiences, coordinate development and discuss 'family problems', away from meetings where the main interest is on experimental physics

Infant Hand Preference and the Development of Cognitive Abilities

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George Frederick Michel

2016-03-01

Full Text Available Hand preference develops in the first two postnatal years with nearly half of infants exhibiting a consistent early preference for acquiring objects. Others exhibit a more variable developmental trajectory but by the end of their second postnatal year, most exhibit a consistent hand preference for role-differentiated bimanual manipulation. According to some forms of embodiment theory, these differences in hand use patterns should influence the way children interact with their environments, which, in turn, should affect the structure and function of brain development. Such early differences in brain development should result in different trajectories of psychological development. We present evidence that children with consistent early hand preferences exhibit advanced patterns of cognitive development as compared to children who develop a hand preference later. Differences in the developmental trajectory of hand preference are predictive of developmental differences in language, object management skills, and tool-use skills. As predicted by Cassasanto’s body-specificity hypothesis, infants with different hand preferences proceed along different developmental pathways of cognitive functioning.

Biological oscillations for learning walking coordination: dynamic recurrent neural network functionally models physiological central pattern generator.

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Hoellinger, Thomas; Petieau, Mathieu; Duvinage, Matthieu; Castermans, Thierry; Seetharaman, Karthik; Cebolla, Ana-Maria; Bengoetxea, Ana; Ivanenko, Yuri; Dan, Bernard; Cheron, Guy

2013-01-01

The existence of dedicated neuronal modules such as those organized in the cerebral cortex, thalamus, basal ganglia, cerebellum, or spinal cord raises the question of how these functional modules are coordinated for appropriate motor behavior. Study of human locomotion offers an interesting field for addressing this central question. The coordination of the elevation of the 3 leg segments under a planar covariation rule (Borghese et al., 1996) was recently modeled (Barliya et al., 2009) by phase-adjusted simple oscillators shedding new light on the understanding of the central pattern generator (CPG) processing relevant oscillation signals. We describe the use of a dynamic recurrent neural network (DRNN) mimicking the natural oscillatory behavior of human locomotion for reproducing the planar covariation rule in both legs at different walking speeds. Neural network learning was based on sinusoid signals integrating frequency and amplitude features of the first three harmonics of the sagittal elevation angles of the thigh, shank, and foot of each lower limb. We verified the biological plausibility of the neural networks. Best results were obtained with oscillations extracted from the first three harmonics in comparison to oscillations outside the harmonic frequency peaks. Physiological replication steadily increased with the number of neuronal units from 1 to 80, where similarity index reached 0.99. Analysis of synaptic weighting showed that the proportion of inhibitory connections consistently increased with the number of neuronal units in the DRNN. This emerging property in the artificial neural networks resonates with recent advances in neurophysiology of inhibitory neurons that are involved in central nervous system oscillatory activities. The main message of this study is that this type of DRNN may offer a useful model of physiological central pattern generator for gaining insights in basic research and developing clinical applications.

[Algorithms for treatment of complex hand injuries].

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Pillukat, T; Prommersberger, K-J

2011-07-01

The primary treatment strongly influences the course and prognosis of hand injuries. Complex injuries which compromise functional recovery are especially challenging. Despite an apparently unlimited number of injury patterns it is possible to develop strategies which facilitate a standardized approach to operative treatment. In this situation algorithms can be important guidelines for a rational approach. The following algorithms have been proven in the treatment of complex injuries of the hand by our own experience. They were modified according to the current literature and refer to prehospital care, emergency room management, basic strategy in general and reconstruction of bone and joints, vessels, nerves, tendons and soft tissue coverage in detail. Algorithms facilitate the treatment of severe hand injuries. Applying simple yes/no decisions complex injury patterns are split into distinct partial problems which can be managed step by step.

Joint Coordination and Muscle Activities of Ballet Dancers During Tiptoe Standing.

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Tanabe, Hiroko; Fujii, Keisuke; Kouzaki, Motoki

2017-01-01

We aimed to investigate joint coordination of lower limbs in dancers during tiptoe standing and the relationship between joint coordination and muscle coactivation. Seven female ballet dancers performed tiptoe standing with six leg positions (fi e classical dance positions and one modern dance position) for 10 s. The kinematic data of the metatarsophalangeal (MP), ankle, knee, and hip joints was collected, and surface electromyography (EMG) of over 13 lower limb muscles was conducted. Principal component analysis was performed to determine joint coordination. MP-ankle and ankle-knee had in-phase coordination, whereas knee-hip showed anti-phase coordination in the sagittal plane. In addition, most EMG-EMG coherence around the MP and ankle joints was significant up to 50 Hz when these two joints swayed with in-phase. This suggests that different joint coordination patterns are associated with neural processing related to different muscle coactivation patterns. In conclusion, ballet dancers showed in-phase coordination from the MP to knee joints, which was associated with muscle coactivation to a higher frequency domain (up to 50 Hz) in comparison with anti-phase coordination.

Measuring hand function in the young child.

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Ho, Emily S

2010-01-01

Assessing outcomes is vital in any hand therapy practice setting, as it is the primary method of determining whether or not a treatment program is working. In the pediatric population, determining improvements in hand function can be challenging. The author describes using a developmental perspective to evaluate hand function for infants and young children. The utilization of a consistent approach to play along with standard toys is described in this article as a method to evaluate the quality of hand function throughout developmental grasp patterns. Copyright © 2010 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

A central pattern generator producing alternative outputs: pattern, strength, and dynamics of premotor synaptic input to leech heart motor neurons.

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Norris, Brian J; Weaver, Adam L; Wenning, Angela; García, Paul S; Calabrese, Ronald L

2007-11-01

The central pattern generator (CPG) for heartbeat in medicinal leeches consists of seven identified pairs of segmental heart interneurons and one unidentified pair. Four of the identified pairs and the unidentified pair of interneurons make inhibitory synaptic connections with segmental heart motor neurons. The CPG produces a side-to-side asymmetric pattern of intersegmental coordination among ipsilateral premotor interneurons corresponding to a similarly asymmetric fictive motor pattern in heart motor neurons, and asymmetric constriction pattern of the two tubular hearts, synchronous and peristaltic. Using extracellular recordings from premotor interneurons and voltage-clamp recordings of ipsilateral segmental motor neurons in 69 isolated nerve cords, we assessed the strength and dynamics of premotor inhibitory synaptic output onto the entire ensemble of heart motor neurons and the associated conduction delays in both coordination modes. We conclude that premotor interneurons establish a stereotypical pattern of intersegmental synaptic connectivity, strengths, and dynamics that is invariant across coordination modes, despite wide variations among preparations. These data coupled with a previous description of the temporal pattern of premotor interneuron activity and relative phasing of motor neuron activity in the two coordination modes enable a direct assessment of how premotor interneurons through their temporal pattern of activity and their spatial pattern of synaptic connectivity, strengths, and dynamics coordinate segmental motor neurons into a functional pattern of activity.

Predicting hand function in older adults: evaluations of grip strength, arm curl strength, and manual dexterity.

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Liu, Chiung-Ju; Marie, Deana; Fredrick, Aaron; Bertram, Jessica; Utley, Kristen; Fess, Elaine Ewing

2017-08-01

Hand function is critical for independence in activities of daily living for older adults. The purpose of this study was to examine how grip strength, arm curl strength, and manual dexterous coordination contributed to time-based versus self-report assessment of hand function in community-dwelling older adults. Adults aged ≥60 years without low vision or neurological disorders were recruited. Purdue Pegboard Test, Jamar hand dynamometer, 30-second arm curl test, Jebsen-Taylor Hand Function Test, and the Late-Life Function and Disability Instrument were administered to assess manual dexterous coordination, grip strength, arm curl strength, time-based hand function, and self-report of hand function, respectively. Eighty-four adults (mean age = 72 years) completed the study. Hierarchical multiple regressions show that older adults with better arm curl strength (β = -.25, p function test. In comparison, older adults with better grip strength (β = .40, p function. The relationship between grip strength and hand function may be test-specific. Grip strength becomes a significant factor when the test requires grip strength to successfully complete the test tasks. Arm curl strength independently contributed to hand function in both time-based and self-report assessments, indicating that strength of extrinsic muscles of the hand are essential for hand function.

Getting hold of approaching objects : In search of a common control of hand-closure initiation in catching and grasping

NARCIS (Netherlands)

van de Kamp, Cornelis; Bongers, Raoul M.; Zaal, Frank T. J. M.

Both in the catching and grasping component of prehension, the hand opens and closes before hand-object contact is made. The initiation of hand closure has to be coordinated with the time course of the decrease of the distance between the hand and the target object, i.e., with the reaching component

Between-hand difference in ipsilateral deactivation is associated with hand lateralization: fMRI mapping of 284 volunteers balanced for handedness

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Nathalie eTzourio-Mazoyer

2015-02-01

Full Text Available In right-handers, an increase in the pace of dominant hand movement results in increased ipsilateral deactivation of the primary motor cortex (M1. By contrast, an increase in non-dominant hand movement frequency is associated with reduced ipsilateral deactivation. This pattern suggests that inhibitory processes support right hand dominance in right-handers and raises the issues of whether this phenomenon also supports left hand preference in left-handers, and/or whether it relates to asymmetry of manual ability in either group. Thanks to the BIL&GIN, a database dedicated to the investigation of hemispheric specialization, we studied the variation in M1 activity during right and left finger tapping tasks in a sample of 284 healthy participants balanced for handedness. An M1 fMRI localizer was defined for each participant as an 8 mm diameter sphere centered on the motor activation peak. Right-handers exhibited significantly larger deactivation of the ipsilateral M1 when moving their dominant hand than their non-dominant hand. In contrast, left-handers exhibited comparable ipsilateral M1 deactivation during either hand movement, reflecting a bilateral cortical specialization. This pattern is likely related to left-handers’ good performances with their right hand and consequent lower asymmetry in manual ability compared with right-handers. Finally, inter-individual analyses over the whole sample demonstrated that the larger the difference in manual skill across hands, the larger the difference in ipsilateral deactivation. Overall, we propose that difference in ipsilateral deactivation is a marker of difference in manual ability asymmetry reflecting differences in the strength of transcallosal inhibition when a given hand is moving.

Coordination of respiration and swallowing: functional pattern and relevance of vocal folds closure

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Milton Melciades Barbosa Costa

2010-03-01

Full Text Available CONTEXT: Breathing and swallowing coordination, despite the expressive number of study, remain as theme deserving further research. OBJECTIVE: To identify a coordination pattern between swallowing and the natural breathing pause that occur in association with it (swallowing apnea and also the relevance of the vocal folds closure in this process. METHODS: Sixty-six adults, male and female, including normal health people, post-laryngectomy individuals and patients with digestive complaints without dysphagia were analyzed. The respiratory air flux interruptions produced by wet requested swallows and dry, requested and spontaneous swallows, were registered using thermo and piezoelectric receptors coupled to synectics medical manometry equipment, using Polygram upper 4.21 software. The results were analyzed with the Chi-square (3×2 and (2×2 nonparametric independency test with P = 0.05. RESULTS: Swallowing apnea is a preventive breathing stop that start just before and stay present during all deglutition pharyngeal phase. It is a well coordinated phenomena that occur as pattern in association with low elastic resistance of the lung, on the expiratory final phase until inspiration initial phase. This breathing stoppage it is usually followed by a short expiraton preceding a new breathing cycle. The swallow apnea and vocal folds closure are both independents mechanisms. CONCLUSION: It is possible to suppose that in the subconscious condition, swallowing apnea is integrated under coordination of the same control mechanism that also involves the elastic resistance of the lung.CONTEXTO: Apesar do expressivo número de estudos sobre a coordenação da respiração com a deglutição, o tema permanece aberto à pesquisa. OBJETIVO: Identificar um padrão de coordenação entre a pausa respiratória e a deglutição que ocorre em associação a esta usual apneia (apneia de deglutição e estabelecer a importância do fechamento das pregas vocais que ocorre

Positional dependence of scale size and shape in butterfly wings: wing-wide phenotypic coordination of color-pattern elements and background.

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Kusaba, Kiseki; Otaki, Joji M

2009-02-01

Butterfly wing color-patterns are a phenotypically coordinated array of scales whose color is determined as cellular interpretation outputs for morphogenic signals. Here we investigated distribution patterns of scale shape and size in relation to position and coloration on the hindwings of a nymphalid butterfly Junonia orithya. Most scales had a smooth edge but scales at and near the natural and ectopic eyespot foci and in the postbasal area were jagged. Scale size decreased regularly from the postbasal to distal areas, and eyespots occasionally had larger scales than the background. Reasonable correlations were obtained between the eyespot size and focal scale size in females. Histological and real-time individual observations of the color-pattern developmental sequence showed that the background brown and blue colors expanded from the postbasal to distal areas independently from the color-pattern elements such as eyespots. These data suggest that morphogenic signals for coloration directly or indirectly influence the scale shape and size and that the blue "background" is organized by a long-range signal from an unidentified organizing center in J. orithya.

Flight feather attachment in rock pigeons (Columba livia): covert feathers and smooth muscle coordinate a morphing wing.

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Hieronymus, Tobin L

2016-11-01

Mechanisms for passively coordinating forelimb movements and flight feather abduction and adduction have been described separately from both in vivo and ex vivo studies. Skeletal coordination has been identified as a way for birds to simplify the neuromotor task of controlling flight stroke, but an understanding of the relationship between skeletal coordination and the coordination of the aerodynamic control surface (the flight feathers) has been slow to materialize. This break between the biomechanical and aerodynamic approaches - between skeletal kinematics and airfoil shape - has hindered the study of dynamic flight behaviors. Here I use dissection and histology to identify previously overlooked interconnections between musculoskeletal elements and flight feathers. Many of these structures are well-placed to directly link elements of the passive musculoskeletal coordination system with flight feather movements. Small bundles of smooth muscle form prominent connections between upper forearm coverts (deck feathers) and the ulna, as well as the majority of interconnections between major flight feathers of the hand. Abundant smooth muscle may play a role in efficient maintenance of folded wing posture, and may also provide an autonomically regulated means of tuning wing shape and aeroelastic behavior in flight. The pattern of muscular and ligamentous linkages of flight feathers to underlying muscle and bone may provide predictable passive guidance for the shape of the airfoil during flight stroke. The structures described here provide an anatomical touchstone for in vivo experimental tests of wing surface coordination in an extensively researched avian model species. © 2016 Anatomical Society.

Cortical Asymmetries during Hand Laterality Task Vary with Hand Laterality: A fMRI Study in 295 Participants

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Mellet, Emmanuel; Mazoyer, Bernard; Leroux, Gaelle; Joliot, Marc; Tzourio-Mazoyer, Nathalie

2016-01-01

The aim of this study was to characterize, using fMRI, the functional asymmetries of hand laterality task (HLT) in a sample of 295 participants balanced for handedness. During HLT, participants have to decide whether the displayed picture of a hand represent a right or a left hand. Pictures of hands’ back view were presented for 150 ms in the right or left hemifield. At the whole hemisphere level, we evidenced that the laterality of the hand and of the hemifield in which the picture was displayed combined their effects on the hemispheric asymmetry in an additive way. We then identified a set of 17 functional homotopic regions of interest (hROIs) including premotor, motor, somatosensory and parietal regions, whose activity and asymmetry varied with the laterality of the presented hands. When the laterality of a right hand had to be evaluated, these areas showed stronger leftward asymmetry, the hROI located in the primary motor area showing a significant larger effect than all other hROIs. In addition a subset of six parietal regions involved in visuo-motor integration together with two postcentral areas showed a variation in asymmetry with hemifield of presentation. Finally, while handedness had no effect at the hemispheric level, two regions located in the parietal operculum and intraparietal sulcus exhibited larger leftward asymmetry with right handedness independently of the hand of presentation. The present results extend those of previous works in showing a shift of asymmetries during HLT according to the hand presented in sensorimotor areas including primary motor cortex. This shift was not affected by manual preference. They also demonstrate that the coordination of visual information and handedness identification of hands relied on the coexistence of contralateral motor and visual representations in the superior parietal lobe and the postcentral gyrus. PMID:27999536

The effects of MicroRNA transfections on global patterns of gene expression in ovarian cancer cells are functionally coordinated

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Shahab Shubin W

2012-08-01

Full Text Available Abstract Background MicroRNAs (miRNAs are a class of small RNAs that have been linked to a number of diseases including cancer. The potential application of miRNAs in the diagnostics and therapeutics of ovarian and other cancers is an area of intense interest. A current challenge is the inability to accurately predict the functional consequences of exogenous modulations in the levels of potentially therapeutic miRNAs. Methods In an initial effort to systematically address this issue, we conducted miRNA transfection experiments using two miRNAs (miR-7, miR-128. We monitored the consequent changes in global patterns of gene expression by microarray and quantitative (real-time polymerase chain reaction. Network analysis of the expression data was used to predict the consequence of each transfection on cellular function and these predictions were experimentally tested. Results While ~20% of the changes in expression patterns of hundreds to thousands of genes could be attributed to direct miRNA-mRNA interactions, the majority of the changes are indirect, involving the downstream consequences of miRNA-mediated changes in regulatory gene expression. The changes in gene expression induced by individual miRNAs are functionally coordinated but distinct between the two miRNAs. MiR-7 transfection into ovarian cancer cells induces changes in cell adhesion and other developmental networks previously associated with epithelial-mesenchymal transitions (EMT and other processes linked with metastasis. In contrast, miR-128 transfection induces changes in cell cycle control and other processes commonly linked with cellular replication. Conclusions The functionally coordinated patterns of gene expression displayed by different families of miRNAs have the potential to provide clinicians with a strategy to treat cancers from a systems rather than a single gene perspective.

The potential roles of T-type Ca2+ channels in motor coordination

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Young-Gyun ePark

2013-10-01

Full Text Available Specific behavioral patterns are expressed by complex combinations of muscle coordination. Tremors are simple behavioral patterns and are the focus of studies investigating motor coordination mechanisms in the brain. T-type Ca2+ channels mediate intrinsic neuronal oscillations and rhythmic burst spiking, and facilitate the generation of tremor rhythms in motor circuits. Despite substantial evidence that T-type Ca2+ channels mediate pathological tremors, their roles in physiological motor coordination and behavior remain unknown. Here, we review recent progress in understanding the roles that T-type Ca2+ channels play under pathological conditions, and discuss the potential relevance of these channels in mediating physiological motor coordination.

The Hot Hand Belief and Framing Effects

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MacMahon, Clare; Köppen, Jörn; Raab, Markus

2014-01-01

Purpose: Recent evidence of the hot hand in sport--where success breeds success in a positive recency of successful shots, for instance--indicates that this pattern does not actually exist. Yet the belief persists. We used 2 studies to explore the effects of framing on the hot hand belief in sport. We looked at the effect of sport experience and…

Musculoskeletal model-based control interface mimics physiologic hand dynamics during path tracing task

Science.gov (United States)

Crouch, Dustin L.; (Helen Huang, He

2017-06-01

Objective. We investigated the feasibility of a novel, customizable, simplified EMG-driven musculoskeletal model for estimating coordinated hand and wrist motions during a real-time path tracing task. Approach. A two-degree-of-freedom computational musculoskeletal model was implemented for real-time EMG-driven control of a stick figure hand displayed on a computer screen. After 5-10 minutes of undirected practice, subjects were given three attempts to trace 10 straight paths, one at a time, with the fingertip of the virtual hand. Able-bodied subjects completed the task on two separate test days. Main results. Across subjects and test days, there was a significant linear relationship between log-transformed measures of accuracy and speed (Pearson’s r  =  0.25, p  bodied subjects in 8 of 10 trials. For able-bodied subjects, tracing accuracy was lower at the extremes of the model’s range of motion, though there was no apparent relationship between tracing accuracy and fingertip location for the amputee. Our result suggests that, unlike able-bodied subjects, the amputee’s motor control patterns were not accustomed to the multi-joint dynamics of the wrist and hand, possibly as a result of post-amputation cortical plasticity, disuse, or sensory deficits. Significance. To our knowledge, our study is one of very few that have demonstrated the real-time simultaneous control of multi-joint movements, especially wrist and finger movements, using an EMG-driven musculoskeletal model, which differs from the many data-driven algorithms that dominate the literature on EMG-driven prosthesis control. Real-time control was achieved with very little training and simple, quick (~15 s) calibration. Thus, our model is potentially a practical and effective control platform for multifunctional myoelectric prostheses that could restore more life-like hand function for individuals with upper limb amputation.

Coordination of Cellular Dynamics Contributes to Tooth Epithelium Deformations

Science.gov (United States)

Morita, Ritsuko; Kihira, Miho; Nakatsu, Yousuke; Nomoto, Yohei; Ogawa, Miho; Ohashi, Kazumasa; Mizuno, Kensaku; Tachikawa, Tetsuhiko; Ishimoto, Yukitaka; Morishita, Yoshihiro; Tsuji, Takashi

2016-01-01

The morphologies of ectodermal organs are shaped by appropriate combinations of several deformation modes, such as invagination and anisotropic tissue elongation. However, how multicellular dynamics are coordinated during deformation processes remains to be elucidated. Here, we developed a four-dimensional (4D) analysis system for tracking cell movement and division at a single-cell resolution in developing tooth epithelium. The expression patterns of a Fucci probe clarified the region- and stage-specific cell cycle patterns within the tooth germ, which were in good agreement with the pattern of the volume growth rate estimated from tissue-level deformation analysis. Cellular motility was higher in the regions with higher growth rates, while the mitotic orientation was significantly biased along the direction of tissue elongation in the epithelium. Further, these spatio-temporal patterns of cellular dynamics and tissue-level deformation were highly correlated with that of the activity of cofilin, which is an actin depolymerization factor, suggesting that the coordination of cellular dynamics via actin remodeling plays an important role in tooth epithelial morphogenesis. Our system enhances the understanding of how cellular behaviors are coordinated during ectodermal organogenesis, which cannot be observed from histological analyses. PMID:27588418

Hand Fatigue Analysis Using Quantitative Evaluation of Variability in Drawing Patterns

Directory of Open Access Journals (Sweden)

mohamadali Sanjari

2015-02-01

Full Text Available Background & aim: Muscle fatigue is defined as the reduced power generation capacity of a muscle or muscle group after activity which can lead to a variety of lesions. The purpose of the present study was to define the fatigue analysis by quantitative analysis using drawing patterns. Methods: the present cross-sectional study was conducted on 37 healthy volunteers (6 men and 31 women aged 18-30 years. Before & immediately after a fatigue protocol, quantitative assessment of hand drawing skills was performed by drawing repeated, overlapping, and concentric circles. The test was conducted in three sessions with an interval of 48-72 hours. Drawing was recorded by a digital tablet. Data were statistically analyzed using paired t-test and repeated measure ANOVA. Result: In drawing time series data analysis, at fatigue level of 100%, the variables standard deviation along x axis (SDx, standard deviation of velocity on both x and y axis (SDVx and SDVy and resultant vector velocity standard deviation (SDVR, showed significant differences after fatigue (P<0.05. In comparison of variables after the three fatigue levels, SDx showed significant difference (P<0.05. Conclusions: structurally full fatigue showed significant differences with other levels of fatigue, so it contributed to significant variability in drawing parameters. The method used in the present study recognized the fatigue in high frequency motion as well.

A pilot study on the sexual side effects of finasteride as related to hand preference for men undergoing treatment of male pattern baldness.

Science.gov (United States)

Motofei, Ion G; Rowland, David L; Georgescu, Simona R; Baconi, Daniela L; Dimcevici, Nicoleta P; Paunica, Stana; Constantin, Vlad D; Balalau, Cristian

2013-04-01

To investigate the relationships between pharmacologically induced deprivation of dihydrotestosterone, sexual arousal, libido and hand preference, by comparing the self-reported sexual response prior to and during reception of the anti-androgen finasteride in men undergoing treatment for male pattern baldness. In total, 33 sexually healthy Romanian men participated in this study. Patients prospectively provided information regarding their sexual functioning (over 4 weeks), as measured by the International Index of Erectile Function (IIEF) prior to and after commencing treatment with 1 mg finasteride for male pattern baldness. Overall IIEF scores as well as the erectile function, orgasmic function, sexual desire and overall satisfaction subscales showed group, treatment and group by treatment effects. The intercourse satisfaction subscale showed group and group by treatment effects. On most subscales, right-handed men showed no effect or lower sexual function whereas left-handed men reported no effect or improved sexual function, primarily. These results suggest that the sexual effects of dihydrotestosterone deprivation may depend on handedness--a proxy variable that may represent cognitive style--which lends further support to the idea of two distinct neuroendocrine psychosexual axes. They further suggest that detection of such sexual effects may be enhanced by using research methodologies and communication strategies that increase patients' sensitization to such effects. © 2012 THE AUTHORS. BJU INTERNATIONAL © 2012 BJU INTERNATIONAL.

The hot hand belief and framing effects.

Science.gov (United States)

MacMahon, Clare; Köppen, Jörn; Raab, Markus

2014-09-01

Recent evidence of the hot hand in sport-where success breeds success in a positive recency of successful shots, for instance-indicates that this pattern does not actually exist. Yet the belief persists. We used 2 studies to explore the effects of framing on the hot hand belief in sport. We looked at the effect of sport experience and task on the perception of baseball pitch behavior as well as the hot hand belief and free-throw behavior in basketball. Study 1 asked participants to designate outcomes with different alternation rates as the result of baseball pitches or coin tosses. Study 2 examined basketball free-throw behavior and measured predicted success before each shot as well as general belief in the hot hand pattern. The results of Study 1 illustrate that experience and stimulus alternation rates influence the perception of chance in human performance tasks. Study 2 shows that physically performing an act and making judgments are related. Specifically, beliefs were related to overall performance, with more successful shooters showing greater belief in the hot hand and greater predicted success for upcoming shots. Both of these studies highlight that the hot hand belief is influenced by framing, which leads to instability and situational contingencies. We show the specific effects of framing using accumulated experience of the individual with the sport and knowledge of its structure and specific experience with sport actions (basketball shots) prior to judgments.

Steady and transient coordination structures of walking and running

NARCIS (Netherlands)

Lamoth, C. J. C.; Daffertshofer, A.; Huys, R.; Beek, P. J.

We studied multisegmental coordination and stride characteristics in nine participants while walking and running on a treadmill. The study's main aim was to evaluate the coordination patterns of walking and running and their variance as a function of locomotion speed, with a specific focus on gait

Steady and transient coordination structures of walking and running

NARCIS (Netherlands)

Lamoth, C.J.C.; Daffertshofer, A.; Huys, R.; Beek, P.J.

2009-01-01

We studied multisegmental coordination and stride characteristics in nine participants while walking and running on a treadmill. The study's main aim was to evaluate the coordination patterns of walking and running and their variance as a function of locomotion speed, with a specific focus on gait

Information theoretic measures of network coordination in high-frequency scalp EEG reveal dynamic patterns associated with seizure termination.

Science.gov (United States)

Stamoulis, Catherine; Schomer, Donald L; Chang, Bernard S

2013-08-01

How a seizure terminates is still under-studied and, despite its clinical importance, remains an obscure phase of seizure evolution. Recent studies of seizure-related scalp EEGs at frequencies >100 Hz suggest that neural activity, in the form of oscillations and/or neuronal network interactions, may play an important role in preictal/ictal seizure evolution (Andrade-Valenca et al., 2011; Stamoulis et al., 2012). However, the role of high-frequency activity in seizure termination, is unknown, if it exists at all. Using information theoretic measures of network coordination, this study investigated ictal and immediate postictal neurodynamic interactions encoded in scalp EEGs from a relatively small sample of 8 patients with focal epilepsy and multiple seizures originating in temporal and/or frontal brain regions, at frequencies ≤ 100 Hz and >100 Hz, respectively. Despite some heterogeneity in the dynamics of these interactions, consistent patterns were also estimated. Specifically, in several seizures, linear or non-linear increase in high-frequency neuronal coordination during ictal intervals, coincided with a corresponding decrease in coordination at frequencies interval, which continues during the postictal interval. This may be one of several possible mechanisms that facilitate seizure termination. In fact, inhibition of pairwise interactions between EEGs by other signals in their spatial neighborhood, quantified by negative interaction information, was estimated at frequencies ≤ 100 Hz, at least in some seizures. Copyright © 2013 Elsevier B.V. All rights reserved.

European electricity markets reforms: the 'visible hand' of public coordination

International Nuclear Information System (INIS)

Finon, Dominique; Roques, Fabien

2013-01-01

The paper investigates how proposed reforms on policies to maintain generation adequacy and encourage clean technology investments in a number of European countries modify the role of the market. In these reforms the government, regulator and system operator take on explicit planning and coordination responsibilities with the introduction of capacity mechanisms and long-term support for clean technologies. We highlight the interactions of these mechanisms with the electricity market and how they reallocate risks between generators, government and consumers. The different mechanisms offer varying degrees of autonomy to generators with regards to investment decisions. In a prospective way, the paper also explores how designs of these different mechanisms might converge towards a unified technology neutral mechanism in the long-run. This could involve auctioning of long-term contracts for all types of existing and new capacities, whether it is low carbon or fossil fueled. (authors)

Hand Movements and Braille Reading Efficiency: Data from the Alphabetic Braille and Contracted Braille Study

Science.gov (United States)

Wright, Tessa; Wormsley, Diane P.; Kamei-Hannan, Cheryl

2009-01-01

Using a subset of data from the Alphabetic Braille and Contracted Braille Study, researchers analyzed the patterns and characteristics of hand movements as predictors of reading performance. Statistically significant differences were found between one- and two-handed readers and between patterns of hand movements and reading rates. (Contains 6…

Real-Time Hand Position Sensing Technology Based on Human Body Electrostatics

Directory of Open Access Journals (Sweden)

Kai Tang

2018-05-01

Full Text Available Non-contact human-computer interactions (HCI based on hand gestures have been widely investigated. Here, we present a novel method to locate the real-time position of the hand using the electrostatics of the human body. This method has many advantages, including a delay of less than one millisecond, low cost, and does not require a camera or wearable devices. A formula is first created to sense array signals with five spherical electrodes. Next, a solving algorithm for the real-time measured hand position is introduced and solving equations for three-dimensional coordinates of hand position are obtained. A non-contact real-time hand position sensing system was established to perform verification experiments, and the principle error of the algorithm and the systematic noise were also analyzed. The results show that this novel technology can determine the dynamic parameters of hand movements with good robustness to meet the requirements of complicated HCI.

Cyclical Patterns of Hand, Foot and Mouth Disease Caused by Enterovirus A71 in Malaysia

Science.gov (United States)

NikNadia, NMN; Sam, I-Ching; Rampal, Sanjay; WanNorAmalina, WMZ; NurAtifah, Ghazali; Verasahib, Khebir; Ong, Chia Ching; MohdAdib, MohdAidinniza; Chan, Yoke Fun

2016-01-01

Enterovirus A71 (EV-A71) is an important emerging pathogen causing large epidemics of hand, foot and mouth disease (HFMD) in children. In Malaysia, since the first EV-A71 epidemic in 1997, recurrent cyclical epidemics have occurred every 2–3 years for reasons that remain unclear. We hypothesize that this cyclical pattern is due to changes in population immunity in children (measured as seroprevalence). Neutralizing antibody titers against EV-A71 were measured in 2,141 residual serum samples collected from children ≤12 years old between 1995 and 2012 to determine the seroprevalence of EV-A71. Reported national HFMD incidence was highest in children Malaysia is mainly due to the fall of population immunity accompanying the accumulation of susceptible children between epidemics. This study will impact the future planning, timing and target populations for vaccine programs. PMID:27010319

Studies on dielectric properties of ferrocenylhydrazone coordinated polymers irradiated by γ-rays

International Nuclear Information System (INIS)

Lin Yun; Chen Jie; Lin Zhanru

2007-01-01

The three ferrocenylhydrazone coordinated metal polymers were synthesized (PZM). The effect of the 60 Co γ irradiation on microwave dielectric properties and their temperature-dielectric properties were studies. It has been found that the dielectric parameters (ε', tgδ) of coordinated polymers increase along with the absorbed doses and coordinated metals in order Cu, Co, Ni, However, the dependent curves of dielectric parameters on arise-down temperature are universal. On the other hand, the small changes in chemical structure before and after irradiation were confirmed by IR differential spectrometry and SEM. It is possible to make such coordinated polymers as a multifunctional polymeric material with optical, electric and magnetic properties, which may be potentially used in microwave communication. (authors)

Emergent coordination underlying learning to reach to grasp with a brain-machine interface.

Science.gov (United States)

Vaidya, Mukta; Balasubramanian, Karthikeyan; Southerland, Joshua; Badreldin, Islam; Eleryan, Ahmed; Shattuck, Kelsey; Gururangan, Suchin; Slutzky, Marc; Osborne, Leslie; Fagg, Andrew; Oweiss, Karim; Hatsopoulos, Nicholas G

2018-04-01

The development of coordinated reach-to-grasp movement has been well studied in infants and children. However, the role of motor cortex during this development is unclear because it is difficult to study in humans. We took the approach of using a brain-machine interface (BMI) paradigm in rhesus macaques with prior therapeutic amputations to examine the emergence of novel, coordinated reach to grasp. Previous research has shown that after amputation, the cortical area previously involved in the control of the lost limb undergoes reorganization, but prior BMI work has largely relied on finding neurons that already encode specific movement-related information. In this study, we taught macaques to cortically control a robotic arm and hand through operant conditioning, using neurons that were not explicitly reach or grasp related. Over the course of training, stereotypical patterns emerged and stabilized in the cross-covariance between the reaching and grasping velocity profiles, between pairs of neurons involved in controlling reach and grasp, and to a comparable, but lesser, extent between other stable neurons in the network. In fact, we found evidence of this structured coordination between pairs composed of all combinations of neurons decoding reach or grasp and other stable neurons in the network. The degree of and participation in coordination was highly correlated across all pair types. Our approach provides a unique model for studying the development of novel, coordinated reach-to-grasp movement at the behavioral and cortical levels. NEW & NOTEWORTHY Given that motor cortex undergoes reorganization after amputation, our work focuses on training nonhuman primates with chronic amputations to use neurons that are not reach or grasp related to control a robotic arm to reach to grasp through the use of operant conditioning, mimicking early development. We studied the development of a novel, coordinated behavior at the behavioral and cortical level, and the neural

Supramolecular Coordination Assemblies Constructed From Multifunctional Azole-Containing Carboxylic Acids

Directory of Open Access Journals (Sweden)

Yuheng Deng

2010-05-01

Full Text Available This paper provides a brief review of recent progress in the field of metal coordination polymers assembled from azole-containing carboxylic acids and gives a diagrammatic summary of the diversity of topological structures in the resulting infinite metal-organic coordination networks (MOCNs. Azole-containing carboxylic acids are a favorable kind of multifunctional ligand to construct various metal complexes with isolated complexes and one, two and three dimensional structures, whose isolated complexes are not the focus of this review. An insight into the topology patterns of the infinite coordination polymers is provided. Analyzed topologies are compared with documented topologies and catalogued by the nature of nodes and connectivity pattern. New topologies which are not available from current topology databases are described and demonstrated graphically.

Quantitative model of transport-aperture coordination during reach-to-grasp movements.

Science.gov (United States)

Rand, Miya K; Shimansky, Y P; Hossain, Abul B M I; Stelmach, George E

2008-06-01

It has been found in our previous studies that the initiation of aperture closure during reach-to-grasp movements occurs when the hand distance to target crosses a threshold that is a function of peak aperture amplitude, hand velocity, and hand acceleration. Thus, a stable relationship between those four movement parameters is observed at the moment of aperture closure initiation. Based on the concept of optimal control of movements (Naslin 1969) and its application for reach-to-grasp movement regulation (Hoff and Arbib 1993), it was hypothesized that the mathematical equation expressing that relationship can be generalized to describe coordination between hand transport and finger aperture during the entire reach-to-grasp movement by adding aperture velocity and acceleration to the above four movement parameters. The present study examines whether this hypothesis is supported by the data obtained in experiments in which young adults performed reach-to-grasp movements in eight combinations of two reach-amplitude conditions and four movement-speed conditions. It was found that linear approximation of the mathematical model described the relationship among the six movement parameters for the entire aperture-closure phase with very high precision for each condition, thus supporting the hypothesis for that phase. Testing whether one mathematical model could approximate the data across all the experimental conditions revealed that it was possible to achieve the same high level of data-fitting precision only by including in the model two additional, condition-encoding parameters and using a nonlinear, artificial neural network-based approximator with two hidden layers comprising three and two neurons, respectively. This result indicates that transport-aperture coordination, as a specific relationship between the parameters of hand transport and finger aperture, significantly depends on the condition-encoding variables. The data from the aperture-opening phase also fit a

Moving attractive virtual agent improves interpersonal coordination stability.

Science.gov (United States)

Zhao, Zhong; Salesse, Robin N; Gueugnon, Mathieu; Schmidt, Richard C; Marin, Ludovic; Bardy, Benoît G

2015-06-01

Interpersonal motor coordination is influenced not only by biomechanical factors such as coordination pattern, oscillating frequency, and individual differences, but also by psychosocial factor such as likability and social competences. Based on the social stereotype of "what is beautiful is good", the present study aimed at investigating whether people coordinate differently with physically attractive people compared to less attractive people. 34 participants were engaged in an interpersonal coordination task with different looking (virtual) agents while performing at the same time a reaction time task. Results showed that participants had more stable motor coordination with the moving attractive than with the less attractive agent, and that the difference in motor coordination could not be interpreted by a specific attention allocation strategy. Our findings provide the evidence that physical attractiveness genuinely affects how people interact with another person, and that the temporal-spatial coordinated movement varies with the partner's psychosocial characteristics. The study broadens the perspective of exploring the effect of additional psychosocial factors on social motor coordination. Copyright © 2015 Elsevier B.V. All rights reserved.

Common Input to Motor Units of Intrinsic and Extrinsic Hand Muscles During Two-Digit Object Hold

OpenAIRE

Winges, Sara A.; Kornatz, Kurt W.; Santello, Marco

2008-01-01

Anatomical and physiological evidence suggests that common input to motor neurons of hand muscles is an important neural mechanism for hand control. To gain insight into the synaptic input underlying the coordination of hand muscles, significant effort has been devoted to describing the distribution of common input across motor units of extrinsic muscles. Much less is known, however, about the distribution of common input to motor units belonging to different intrinsic muscles and to intrinsi...

Intrinsic Hand Muscle Activation for Grasp and Horizontal Transport

OpenAIRE

Winges, Sara A.; Kundu, Bornali; Soechting, John F.; Flanders, Martha

2007-01-01

During object manipulation, the hand and arm muscles produce internal forces on the object (grasping forces) and forces that result in external translation or rotation of the object in space (transport forces). The present study tested whether the intrinsic hand muscles are actively involved in transport as well as grasping. Intrinsic hand muscle activity increased with increasing demands for grasp stability, but also showed the timing and directional tuning patterns appropriate for actively ...

Functional coordination of muscles underlying changes in behavioural dynamics.

Science.gov (United States)

Vernooij, Carlijn A; Rao, Guillaume; Perdikis, Dionysios; Huys, Raoul; Jirsa, Viktor K; Temprado, Jean-Jacques

2016-06-10

The dynamical systems approach addresses Bernstein's degrees of freedom problem by assuming that the neuro-musculo-skeletal system transiently assembles and dismantles its components into functional units (or synergies) to meet task demands. Strikingly, little is known from a dynamical point of view about the functioning of the muscular sub-system in this process. To investigate the interaction between the dynamical organisation at muscular and behavioural levels, we searched for specific signatures of a phase transition in muscular coordination when a transition is displayed at the behavioural level. Our results provide evidence that, during Fitts' task when behaviour switches to a different dynamical regime, muscular activation displays typical signatures of a phase transition; a reorganisation in muscular coordination patterns accompanied by a peak in the variability of muscle activation. This suggests that consistent changes occur in coordination processes across the different levels of description (i.e., behaviour and muscles). Specifically, in Fitts' task, target size acts as a control parameter that induces a destabilisation and a reorganisation of coordination patterns at different levels of the neuro-musculo-skeletal system.

Learning Arm/Hand Coordination with an Altered Visual Input

Directory of Open Access Journals (Sweden)

Simona Denisia Iftime Nielsen

2010-01-01

Full Text Available The focus of this study was to test a novel tool for the analysis of motor coordination with an altered visual input. The altered visual input was created using special glasses that presented the view as recorded by a video camera placed at various positions around the subject. The camera was positioned at a frontal (F, lateral (L, or top (T position with respect to the subject. We studied the differences between the arm-end (wrist trajectories while grasping an object between altered vision (F, L, and T conditions and normal vision (N in ten subjects. The outcome measures from the analysis were the trajectory errors, the movement parameters, and the time of execution. We found substantial trajectory errors and an increased execution time at the baseline of the study. We also found that trajectory errors decreased in all conditions after three days of practice with the altered vision in the F condition only for 20 minutes per day, suggesting that recalibration of the visual systems occurred relatively quickly. These results indicate that this recalibration occurs via movement training in an altered condition. The results also suggest that recalibration is more difficult to achieve for altered vision in the F and L conditions compared to the T condition. This study has direct implications on the design of new rehabilitation systems.

Body ownership and the four-hand illusion.

Science.gov (United States)

Chen, Wen-Yeo; Huang, Hsu-Chia; Lee, Yen-Tung; Liang, Caleb

2018-02-01

Recent studies of the rubber hand illusion (RHI) have shown that the sense of body ownership is constrained by several factors and yet is still very flexible. However, exactly how flexible is our sense of body ownership? In this study, we address this issue by investigating the following question: is it possible that one may have the illusory experience of owning four hands? Under visual manipulation, the participant adopted the experimenter's first-person perspective (1PP) as if it was his/her own. Sitting face to face, the participant saw four hands-the experimenter's two hands from the adopted 1PP together with the subject's own two hands from the adopted third-person perspective (3PP). We found that: (1) the four-hand illusion did not occur in the passive four-hand condition. (2) In the active four-hand condition, the participants tapped their index fingers, imitated by the experimenter. When tactile stimulations were not provided, the key illusion was not induced, either. (3) Strikingly, once all four hands began to act with the same pattern and received synchronous tactile stimulations at the same time, many participants felt as if they had two more hands. These results show that the sense of body ownership is much more flexible than most researchers have suggested.

Arm-trunk coordination in wheelchair initiation displacement: A study of anticipatory and compensatory postural adjustments during different speeds and directions of propulsion.

Science.gov (United States)

Chikh, Soufien; Garnier, Cyril; Faupin, Arnaud; Pinti, Antonio; Boudet, Samuel; Azaiez, Fairouz; Watelain, Eric

2018-03-13

Arm-trunk coordination during the initiation of displacement in manual wheelchair is a complex task. The objective of this work is to study the arm-trunk coordination by measuring anticipatory and compensatory postural adjustments. Nine healthy subjects participated in the study after being trained in manual wheelchair. They were asked to initiate a displacement in manual wheelchair in three directions (forward vs. left vs. right), with two speeds (spontaneous vs. maximum) and with two initial hand's positions (hands on thighs vs. hands on handrails). Muscular activities in the trunk (postural component) and the arms (focal component) were recorded bilaterally. The results show two strategies for trunk control: An anticipatory adjustment strategy and a compensatory adjustment strategy with a dominance of compensation. These two strategies are influenced by the finalities of displacement in terms of speed and direction depending on the hands positions. Arm-trunk coordination is characterized by an adaptability of anticipatory and compensatory postural adjustments. The study of this type of coordination for subjects with different levels of spinal cord injury could be used to predict the forthcoming displacement and thus assist the user in a complex task. Copyright © 2018 Elsevier Ltd. All rights reserved.

Advanced Myoelectric Control for Robotic Hand-Assisted Training: Outcome from a Stroke Patient.

Science.gov (United States)

Lu, Zhiyuan; Tong, Kai-Yu; Shin, Henry; Li, Sheng; Zhou, Ping

2017-01-01

A hand exoskeleton driven by myoelectric pattern recognition was designed for stroke rehabilitation. It detects and recognizes the user's motion intent based on electromyography (EMG) signals, and then helps the user to accomplish hand motions in real time. The hand exoskeleton can perform six kinds of motions, including the whole hand closing/opening, tripod pinch/opening, and the "gun" sign/opening. A 52-year-old woman, 8 months after stroke, made 20× 2-h visits over 10 weeks to participate in robot-assisted hand training. Though she was unable to move her fingers on her right hand before the training, EMG activities could be detected on her right forearm. In each visit, she took 4× 10-min robot-assisted training sessions, in which she repeated the aforementioned six motion patterns assisted by our intent-driven hand exoskeleton. After the training, her grip force increased from 1.5 to 2.7 kg, her pinch force increased from 1.5 to 2.5 kg, her score of Box and Block test increased from 3 to 7, her score of Fugl-Meyer (Part C) increased from 0 to 7, and her hand function increased from Stage 1 to Stage 2 in Chedoke-McMaster assessment. The results demonstrate the feasibility of robot-assisted training driven by myoelectric pattern recognition after stroke.

Intra- and inter-subject variation in lower limb coordination during countermovement jumps in children and adults

DEFF Research Database (Denmark)

Raffalt, Peter C; Alkjær, Tine; Simonsen, Erik B

2016-01-01

-subject variability. Based on these results, it was concluded that the same movement solutions were available to both age groups, but the children were less able to consistently utilize the individually chosen coordination pattern. Thus, this ability appears to be developed through normal ontogenesis.......The purpose of the present study was to investigate the coordination pattern and coordination variability (intra-subject and inter-subject) in children and adults during vertical countermovement jumps. Ten children (mean age: 11.5±1.8years) and ten adults (mean age: 26.1±4.9years) participated...... in the experiment. Lower body 3D-kinematics and kinetics from both legs were obtained during 9 vertical jumps of each subject. Coordination pattern and coordination variability of intra-limb and inter-limb coupling were established by modified vector coding and continuous relative phase. The adult group jumped...

Endothelial cell motility, coordination and pattern formation during vasculogenesis.

Science.gov (United States)

Czirok, Andras

2013-01-01

How vascular networks assemble is a fundamental problem of developmental biology that also has medical importance. To explain the organizational principles behind vascular patterning, we must understand how can tissue level structures be controlled through cell behavior patterns like motility and adhesion that, in turn, are determined by biochemical signal transduction processes? We discuss the various ideas that have been proposed as mechanisms for vascular network assembly: cell motility guided by extracellular matrix alignment (contact guidance), chemotaxis guided by paracrine and autocrine morphogens, and multicellular sprouting guided by cell-cell contacts. All of these processes yield emergent patterns, thus endothelial cells can form an interconnected structure autonomously, without guidance from an external pre-pattern. © 2013 Wiley Periodicals, Inc.

Children with developmental coordination disorder play active virtual reality games differently than children with typical development.

Science.gov (United States)

Gonsalves, Leandra; Campbell, Amity; Jensen, Lynn; Straker, Leon

2015-03-01

Active virtual reality gaming (AVG) may be useful for children with developmental coordination disorder (DCD) to practice motor skills if their movement patterns are of good quality while engaged in AVG. This study aimed to examine: (1) the quality of motor patterns of children with DCD participating in AVG by comparing them with children with typical development (TD) and (2) whether differences existed in the motor patterns utilized with 2 AVG types: Sony PlayStation 3 Move and Microsoft Xbox 360 Kinect. This was a quasi-experimental, biomechanical laboratory-based study. Twenty-one children with DCD, aged 10 to 12 years, and 19 age- and sex-matched children with TD played a match of table tennis on each AVG type. Hand path, wrist angle, and elbow angle were recorded using a motion analysis system. Linear mixed-model analyses were used to determine differences between DCD and TD groups and Move and Kinect AVG type for forehands and backhands. Children with DCD utilized a slower hand path speed (backhand mean difference [MD]=1.20 m/s; 95% confidence interval [95% CI]=0.41, 1.98); greater wrist extension (forehand MD=34.3°; 95% CI=22.6, 47.0); and greater elbow flexion (forehand MD=22.3°; 95% CI=7.4, 37.1) compared with children with TD when engaged in AVG. There also were differences in movement patterns utilized between AVG types. Only simple kinematic measures were compared, and no data regarding movement outcome were assessed. If a therapeutic treatment goal is to promote movement quality in children with DCD, clinical judgment is required to select the most appropriate AVG type and determine whether movement quality is adequate for unsupervised practice. © 2015 American Physical Therapy Association.

Hand activities in infantile masturbation: a video analysis of 13 cases.

Science.gov (United States)

Hansen, Jonas Kjeldbjerg; Balslev, Thomas

2009-11-01

Infantile masturbation is considered a variant of normal behaviour. The abrupt and spontaneous onset, altered sensorium and autonomic phenomena during episodes may suggest an epileptic fit. Therefore, children with infantile masturbation are often admitted to hospital and undergo unnecessary tests. The purpose of the present study was to provide a detailed description of hand activities in infantile masturbation. The authors reviewed video recordings of 2 boys and 11 girls with infantile masturbation. Position, movements and activities of hands and fingers during episodes were registered. Five patterns of hand activities were registered: Fisting (four infants), grasping of toys, furniture or clothing (ten infants), chorea-like "piano playing" hand movements (two infants), pressure over the diaper/genital region (one infant) and bimanual manipulation of items (four infants). Fisting was primarily observed in the younger infants, and bimanual manipulation was primarily seen in the older infants. Recognizing one or more of the five distinct patterns of hand activities in infantile masturbation may help establishing the diagnosis.

Hand eczema guidelines based on the Danish guidelines for the diagnosis and treatment of hand eczema

DEFF Research Database (Denmark)

Menné, Torkil; Johansen, Jeanne D; Sommerlund, Mette

2011-01-01

Background. Classification of hand eczema has traditionally been based both on aetiology and clinical appearance. For 20% of cases, the aetiology is unknown. Objectives. To suggest a classification based on well-defined aetiology as well as on predefined clinical patterns and on the dynamics of h...

Hand Specific Representations in Language Comprehension

Directory of Open Access Journals (Sweden)

Claire eMoody-Triantis

2014-06-01

Full Text Available Theories of embodied cognition argue that language comprehension involves sensory-motor re-enactments of the actions described. However, the degree of specificity of these re-enactments as well as the relationship between action and language remains a matter of debate. Here we investigate these issues by examining how hand-specific information (left or right hand is recruited in language comprehension and action execution. An fMRI study tested right-handed participants in two separate tasks that were designed to be as similar as possible to increase sensitivity of the comparison across task: an action execution go/no-go task where participants performed right or left hand actions, and a language task where participants read sentences describing the same left or right handed actions as in the execution task. We found that language-induced activity did not match the hand-specific patterns of activity found for action execution in primary somatosensory and motor cortex, but it overlapped with pre-motor and parietal regions associated with action planning. Within these pre-motor regions, both right hand actions and sentences elicited stronger activity than left hand actions and sentences - a dominant hand effect -. Importantly, both dorsal and ventral sections of the left pre-central gyrus were recruited by both tasks, suggesting different action features being recruited. These results suggest that (a language comprehension elicits motor representations that are hand-specific and akin to multimodal action plans, rather than full action re-enactments; and (b language comprehension and action execution share schematic hand-specific representations that are richer for the dominant hand, and thus linked to previous motor experience.

Hand specific representations in language comprehension.

Science.gov (United States)

Moody-Triantis, Claire; Humphreys, Gina F; Gennari, Silvia P

2014-01-01

Theories of embodied cognition argue that language comprehension involves sensory-motor re-enactments of the actions described. However, the degree of specificity of these re-enactments as well as the relationship between action and language remains a matter of debate. Here we investigate these issues by examining how hand-specific information (left or right hand) is recruited in language comprehension and action execution. An fMRI study tested self-reported right-handed participants in two separate tasks that were designed to be as similar as possible to increase sensitivity of the comparison across task: an action execution go/no-go task where participants performed right or left hand actions, and a language task where participants read sentences describing the same left or right handed actions as in the execution task. We found that language-induced activity did not match the hand-specific patterns of activity found for action execution in primary somatosensory and motor cortex, but it overlapped with pre-motor and parietal regions associated with action planning. Within these pre-motor regions, both right hand actions and sentences elicited stronger activity than left hand actions and sentences-a dominant hand effect. Importantly, both dorsal and ventral sections of the left pre-central gyrus were recruited by both tasks, suggesting different action features being recruited. These results suggest that (a) language comprehension elicits motor representations that are hand-specific and akin to multimodal action plans, rather than full action re-enactments; and (b) language comprehension and action execution share schematic hand-specific representations that are richer for the dominant hand, and thus linked to previous motor experience.

Robot hand tackles jobs in hazardous areas

International Nuclear Information System (INIS)

Simms, Mark; Crowder, Richard.

1989-01-01

A robot hand and arm designed to mimic the operation of its human counterpart, developed at the University of Southampton for use in a standard industrial glovebox, is described. It was specifically designed for use in a radioactive environment moving high dosage components around. As dosage limits go down, there is a legal requirement to remove people from that environment. The nine-axis arm is for use in a glove designed for a human hand. Drive for the motors used to power the hand is from three-phase MOSFET inventor cards, the switching pattern controlled by the Hall effect communication sensors integral to each motor. The computer software for the arm allows the hand to be positioned using a joystick on a control box, with three levels of command for grip, pinch and touch. (author)

patterns of knee, hip and hand osteoarthritis in kenyatta national

African Journals Online (AJOL)

presented using tables, pie charts and graphs. RESULTS. Among the 2100 patients with rheumatic diseases, 201 patients had knee, hip or hand AO giving a ... hypertension, diabetes mellitus, heart disease and musculoskeletal disease. The evidence linking obesity to OA has been accumulating. The risk of developing.

Hand veins feature extraction using DT-CNNS

Science.gov (United States)

Malki, Suleyman; Spaanenburg, Lambert

2007-05-01

As the identification process is based on the unique patterns of the users, biometrics technologies are expected to provide highly secure authentication systems. The existing systems using fingerprints or retina patterns are, however, very vulnerable. One's fingerprints are accessible as soon as the person touches a surface, while a high resolution camera easily captures the retina pattern. Thus, both patterns can easily be "stolen" and forged. Beside, technical considerations decrease the usability for these methods. Due to the direct contact with the finger, the sensor gets dirty, which decreases the authentication success ratio. Aligning the eye with a camera to capture the retina pattern gives uncomfortable feeling. On the other hand, vein patterns of either a palm of the hand or a single finger offer stable, unique and repeatable biometrics features. A fingerprint-based identification system using Cellular Neural Networks has already been proposed by Gao. His system covers all stages of a typical fingerprint verification procedure from Image Preprocessing to Feature Matching. This paper performs a critical review of the individual algorithmic steps. Notably, the operation of False Feature Elimination is applied only once instead of 3 times. Furthermore, the number of iterations is limited to 1 for all used templates. Hence, the computational need of the feedback contribution is removed. Consequently the computational effort is drastically reduced without a notable chance in quality. This allows a full integration of the detection mechanism. The system is prototyped on a Xilinx Virtex II Pro P30 FPGA.

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.

Perfect fluid models in noncomoving observational spherical coordinates

International Nuclear Information System (INIS)

Ishak, Mustapha

2004-01-01

We use null spherical (observational) coordinates to describe a class of inhomogeneous cosmological models. The proposed cosmological construction is based on the observer past null cone. A known difficulty in using inhomogeneous models is that the null geodesic equation is not integrable in general. Our choice of null coordinates solves the radial ingoing null geodesic by construction. Furthermore, we use an approach where the velocity field is uniquely calculated from the metric rather than put in by hand. Conveniently, this allows us to explore models in a noncomoving frame of reference. In this frame, we find that the velocity field has shear, acceleration, and expansion rate in general. We show that a comoving frame is not compatible with expanding perfect fluid models in the coordinates proposed and dust models are simply not possible. We describe the models in a noncomoving frame. We use the dust models in a noncomoving frame to outline a fitting procedure

Coordination analysis of players' distribution in football using cross-correlation and vector coding techniques.

Science.gov (United States)

Moura, Felipe Arruda; van Emmerik, Richard E A; Santana, Juliana Exel; Martins, Luiz Eduardo Barreto; Barros, Ricardo Machado Leite de; Cunha, Sergio Augusto

2016-12-01

The purpose of this study was to investigate the coordination between teams spread during football matches using cross-correlation and vector coding techniques. Using a video-based tracking system, we obtained the trajectories of 257 players during 10 matches. Team spread was calculated as functions of time. For a general coordination description, we calculated the cross-correlation between the signals. Vector coding was used to identify the coordination patterns between teams during offensive sequences that ended in shots on goal or defensive tackles. Cross-correlation showed that opponent teams have a tendency to present in-phase coordination, with a short time lag. During offensive sequences, vector coding results showed that, although in-phase coordination dominated, other patterns were observed. We verified that during the early stages, offensive sequences ending in shots on goal present greater anti-phase and attacking team phase periods, compared to sequences ending in tackles. Results suggest that the attacking team may seek to present a contrary behaviour of its opponent (or may lead the adversary behaviour) in the beginning of the attacking play, regarding to the distribution strategy, to increase the chances of a shot on goal. The techniques allowed detecting the coordination patterns between teams, providing additional information about football dynamics and players' interaction.

Unconstrained and contactless hand geometry biometrics.

Science.gov (United States)

de-Santos-Sierra, Alberto; Sánchez-Ávila, Carmen; Del Pozo, Gonzalo Bailador; Guerra-Casanova, Javier

2011-01-01

This paper presents a hand biometric system for contact-less, platform-free scenarios, proposing innovative methods in feature extraction, template creation and template matching. The evaluation of the proposed method considers both the use of three contact-less publicly available hand databases, and the comparison of the performance to two competitive pattern recognition techniques existing in literature: namely support vector machines (SVM) and k-nearest neighbour (k-NN). Results highlight the fact that the proposed method outcomes existing approaches in literature in terms of computational cost, accuracy in human identification, number of extracted features and number of samples for template creation. The proposed method is a suitable solution for human identification in contact-less scenarios based on hand biometrics, providing a feasible solution to devices with limited hardware requirements like mobile devices.

Unconstrained and Contactless Hand Geometry Biometrics

Directory of Open Access Journals (Sweden)

Carmen Sánchez-Ávila

2011-10-01

Full Text Available This paper presents a hand biometric system for contact-less, platform-free scenarios, proposing innovative methods in feature extraction, template creation and template matching. The evaluation of the proposed method considers both the use of three contact-less publicly available hand databases, and the comparison of the performance to two competitive pattern recognition techniques existing in literature: namely Support Vector Machines (SVM and k-Nearest Neighbour (k-NN. Results highlight the fact that the proposed method outcomes existing approaches in literature in terms of computational cost, accuracy in human identification, number of extracted features and number of samples for template creation. The proposed method is a suitable solution for human identification in contact-less scenarios based on hand biometrics, providing a feasible solution to devices with limited hardware requirements like mobile devices.

A Minimal Model Describing Hexapedal Interlimb Coordination: The Tegotae-Based Approach

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Dai Owaki

2017-06-01

Full Text Available Insects exhibit adaptive and versatile locomotion despite their minimal neural computing. Such locomotor patterns are generated via coordination between leg movements, i.e., an interlimb coordination, which is largely controlled in a distributed manner by neural circuits located in thoracic ganglia. However, the mechanism responsible for the interlimb coordination still remains elusive. Understanding this mechanism will help us to elucidate the fundamental control principle of animals' agile locomotion and to realize robots with legs that are truly adaptive and could not be developed solely by conventional control theories. This study aims at providing a “minimal" model of the interlimb coordination mechanism underlying hexapedal locomotion, in the hope that a single control principle could satisfactorily reproduce various aspects of insect locomotion. To this end, we introduce a novel concept we named “Tegotae,” a Japanese concept describing the extent to which a perceived reaction matches an expectation. By using the Tegotae-based approach, we show that a surprisingly systematic design of local sensory feedback mechanisms essential for the interlimb coordination can be realized. We also use a hexapod robot we developed to show that our mathematical model of the interlimb coordination mechanism satisfactorily reproduces various insects' gait patterns.

Solving the robot-world, hand-eye(s) calibration problem with iterative methods

Science.gov (United States)

Robot-world, hand-eye calibration is the problem of determining the transformation between the robot end effector and a camera, as well as the transformation between the robot base and the world coordinate system. This relationship has been modeled as AX = ZB, where X and Z are unknown homogeneous ...

Coordination: Neural, Behavioral and Social Dynamics

CERN Document Server

Fuchs, Armin

2008-01-01

One of the most striking features of Coordination Dynamics is its interdisciplinary character. The problems we are trying to solve in this field range from behavioral phenomena of interlimb coordination and coordination between stimuli and movements (perception-action tasks) through neural activation patterns that can be observed during these tasks to clinical applications and social behavior. It is not surprising that close collaboration among scientists from different fields as psychology, kinesiology, neurology and even physics are imperative to deal with the enormous difficulties we are facing when we try to understand a system as complex as the human brain. The chapters in this volume are not simply write-ups of the lectures given by the experts at the meeting but are written in a way that they give sufficient introductory information to be comprehensible and useful for all interested scientists and students.

Fractures and dislocations of the hand in polytrauma patients: Incidence, injury pattern and functional outcome.

Science.gov (United States)

Ferree, Steven; van der Vliet, Quirine M J; van Heijl, Mark; Houwert, Roderick M; Leenen, Luke P H; Hietbrink, Falco

2017-04-01

Injuries of the hand can cause significant functional impairment, diminished quality of life and delayed return to work. However, the incidence and functional outcome of hand injuries in polytrauma patients is currently unknown. The aim of this study was to determine the incidence, distribution and functional outcome of fractures and dislocation of the hand in polytrauma patients. A single centre retrospective cohort study was performed at a level 1 trauma centre. Polytrauma was defined as patients with an Injury Severity Score of 16 or higher. Fractures and dislocations to the hand were determined. All eligible polytrauma patients with hand injuries were included and a Quick Disability of Arm, Shoulder and Hand questionnaire (QDASH) and Patient-Rated Wrist/Hand Evaluation (PRWHE) were administered. Patients were contacted 1-6 years after trauma. In a cohort of 2046 polytrauma patients 72 patients (3.5%) suffered a hand injury. The functional outcome scores of 52 patients (72%) were obtained. The Metacarpal (48%) and carpal (33%) bones were the most frequently affected. The median QDASH score for all patients with hand injury was 17 (IQR 0-31) and the PRWHE 14 (IQR 0-41). Patients with a concomitant upper extremity injury (p=0.002 for PRWHE, p0.006 for QDASH) and those with higher ISS scores (p=0.034 for PRWHE, QDASH not significant) had worse functional outcome scores. As an example, of the 5 patients with the worst outcome scores 3 suffered an isolated phalangeal injury, all had concomitant upper extremity injury or neurological injuries (3 plexus injuries, 1 severe brain injury). The incidence of hand injuries in polytrauma patients is 3.5%, which is relatively low compared to a general trauma population. Metacarpal and carpal bones were most frequently affected. The functional extremity specific outcome scores are highly influenced by concomitant injuries (upper extremity injuries, neurological injuries and higher ISS). Copyright © 2017 Elsevier Ltd. All

Urban Land Use Efficiency and Coordination in China

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Xiaodong Yang

2017-03-01

Full Text Available Due to the focused pursuit of economic growth in the process of the large-scale urban development of China, the phenomena of low land use efficiency and discordance of land use induce unwanted economic, social, and environmental costs. This paper presents a comprehensive study of urban land use efficiency and of the degree of land use coordination of 33 cities in China, using theoretical analysis, data envelopment analysis, principal component analysis, the coordination coefficient method, and four-quadrant analysis. The findings of this study suggest a gradually increasing proportion of land use efficiency from eastern to central and western regions of China, coinciding with China’s pattern of socioeconomic development. No correlation was found between high levels of urban land use efficiency and the degree of land use coordination; however, a significant correlation was found between low land use efficiency and low degrees of land use coordination. Rational land use planning and policy design can effectively improve both urban land use efficiency and coordination.

Kinematic hand parameters in front crawl at different paces of swimming.

Science.gov (United States)

Samson, Mathias; Monnet, Tony; Bernard, Anthony; Lacouture, Patrick; David, Laurent

2015-11-05

The aim of this study was to investigate the evolution of kinematic hand parameters (sweepback angle, angle of attack, velocity, acceleration and orientation of the hand relative to the absolute coordinate system) throughout an aquatic stroke and to study the possible modifications caused by a variation of the swimming pace. Seventeen competitive swimmers swam at long distance, middle distance and sprint paces. Parameters were calculated from the trajectory of seven markers on the hand measured with an optoelectronic system. Results showed that kinematic hand parameters evolve differently depending on the pace. Angle of attack, sweepback angle, acceleration and orientation of the hand do not vary significantly. The velocity of the hand increases when the pace increases, but only during the less propulsive phases (entry and stretch and downsweep to catch). The more the pace increases and the more the absolute durations of the entry and stretch and downsweep to catch phases decrease. Absolute durations of the insweep and upsweep phases remain constant. During these phases, the propulsive hand forces calculated do not vary significantly when the pace increases. The increase of swimming pace is then explained by the swimmer's capacity to maintain propulsive phases rather than increasing the force generation within each cycle. Copyright © 2015 Elsevier Ltd. All rights reserved.

Coordination chemistry of sugar-phosphate complexes with palladium(II), rhenium(V) and zinc(II)

Energy Technology Data Exchange (ETDEWEB)

Steinborn, Christian Martin

2013-05-21

As described before, some studies dealing with coordination chemistry of sugar phosphates are available but no analogous complexes of Zn{sup II} have been investigated yet. The primary goal of this work is, therefore, to fill this gap. In order to stay close to the active sites of enzymes such as class-II-aldolase, the simple metal fragment Zn{sup II}(dien) is used. NMR spectroscopy is used primarily as analytical method since it enables the investigation of both complex equilibria in solution and pH dependence of metal-binding sites. Since this approach is challenging due to the fast metal-ligand exchange and the absence of CIS values, it is necessary to improve the significance of NMR data collected from sugar-phosphate complexes with Zn{sup II}. Hence, further experiments are performed with molecules similar to sugar phosphates such as reducing and methylated sugars or polyols. Beside NMR spectroscopy, crystal-structure analysis will be used to get more detailed information about the binding pattern of the complexes. Additionally, sugar-phosphate complexes of Pd{sup II} are investigated. Further experiments are conducted, on the one hand, to synthesise more sugarphosphate complexes with ReVON2 fragments, and, on the other hand, to grow crystals confirming the theory about mixed sugar-core-phosphate chelation.

Bimanual coordination and musical experience : The role of intrinsic dynamics and behavioral information

NARCIS (Netherlands)

Verheul, M.H.G.; Geuze, RH

Rhythmic interlimb coordination arises from the interaction of intrinsic dynamics and behavioral information, that is, intention, memory, or external information specifying the required coordination pattern. This study investigates the influence of the content of memorized behavioral information on

Two hands, one brain, and aging.

Science.gov (United States)

Maes, Celine; Gooijers, Jolien; Orban de Xivry, Jean-Jacques; Swinnen, Stephan P; Boisgontier, Matthieu P

2017-04-01

Many activities of daily living require moving both hands in an organized manner in space and time. Therefore, understanding the impact of aging on bimanual coordination is essential for prolonging functional independence and well-being in older adults. Here we investigated the behavioral and neural determinants of bimanual coordination in aging. The studies surveyed in this review reveal that aging is associated with cortical hyper-activity (but also subcortical hypo-activity) during performance of bimanual tasks. In addition to changes in activation in local areas, the interaction between distributed brain areas also exhibits age-related effects, i.e., functional connectivity is increased in the resting brain as well as during task performance. The mechanisms and triggers underlying these functional activation and connectivity changes remain to be investigated. This requires further research investment into the detailed study of interactions between brain structure, function and connectivity. This will also provide the foundation for interventional research programs towards preservation of brain health and behavioral performance by maximizing neuroplasticity potential in older adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

Defensive peripersonal space: the blink reflex evoked by hand stimulation is increased when the hand is near the face.

Science.gov (United States)

Sambo, C F; Liang, M; Cruccu, G; Iannetti, G D

2012-02-01

Electrical stimulation of the median nerve at the wrist may elicit a blink reflex [hand blink reflex (HBR)] mediated by a neural circuit at brain stem level. As, in a Sherringtonian sense, the blink reflex is a defensive response, in a series of experiments we tested, in healthy volunteers, whether and how the HBR is modulated by the proximity of the stimulated hand to the face. Electromyographic activity was recorded from the orbicularis oculi, bilaterally. We observed that the HBR is enhanced when the stimulated hand is inside the peripersonal space of the face, compared with when it is outside, irrespective of whether the proximity of the hand to the face is manipulated by changing the position of the arm (experiment 1) or by rotating the head while keeping the arm position constant (experiment 3). Experiment 2 showed that such HBR enhancement has similar magnitude when the participants have their eyes closed. Experiments 4 and 5 showed, respectively, that the blink reflex elicited by the electrical stimulation of the supraorbital nerve, as well as the N20 wave of the somatosensory evoked potentials elicited by the median nerve stimulation, are entirely unaffected by hand position. Taken together, our results provide compelling evidence that the brain stem circuits mediating the HBR in humans undergo tonic and selective top-down modulation from higher order cortical areas responsible for encoding the location of somatosensory stimuli in external space coordinates. These findings support the existence of a "defensive" peripersonal space, representing a safety margin advantageous for survival.

A mechatronics platform to study prosthetic hand control using EMG signals.

Science.gov (United States)

Geethanjali, P

2016-09-01

In this paper, a low-cost mechatronics platform for the design and development of robotic hands as well as a surface electromyogram (EMG) pattern recognition system is proposed. This paper also explores various EMG classification techniques using a low-cost electronics system in prosthetic hand applications. The proposed platform involves the development of a four channel EMG signal acquisition system; pattern recognition of acquired EMG signals; and development of a digital controller for a robotic hand. Four-channel surface EMG signals, acquired from ten healthy subjects for six different movements of the hand, were used to analyse pattern recognition in prosthetic hand control. Various time domain features were extracted and grouped into five ensembles to compare the influence of features in feature-selective classifiers (SLR) with widely considered non-feature-selective classifiers, such as neural networks (NN), linear discriminant analysis (LDA) and support vector machines (SVM) applied with different kernels. The results divulged that the average classification accuracy of the SVM, with a linear kernel function, outperforms other classifiers with feature ensembles, Hudgin's feature set and auto regression (AR) coefficients. However, the slight improvement in classification accuracy of SVM incurs more processing time and memory space in the low-level controller. The Kruskal-Wallis (KW) test also shows that there is no significant difference in the classification performance of SLR with Hudgin's feature set to that of SVM with Hudgin's features along with AR coefficients. In addition, the KW test shows that SLR was found to be better in respect to computation time and memory space, which is vital in a low-level controller. Similar to SVM, with a linear kernel function, other non-feature selective LDA and NN classifiers also show a slight improvement in performance using twice the features but with the drawback of increased memory space requirement and time

3D palmprint and hand imaging system based on full-field composite color sinusoidal fringe projection technique.

Science.gov (United States)

Zhang, Zonghua; Huang, Shujun; Xu, Yongjia; Chen, Chao; Zhao, Yan; Gao, Nan; Xiao, Yanjun

2013-09-01

Palmprint and hand shape, as two kinds of important biometric characteristics, have been widely studied and applied to human identity recognition. The existing research is based mainly on 2D images, which lose the third-dimensional information. The biological features extracted from 2D images are distorted by pressure and rolling, so the subsequent feature matching and recognition are inaccurate. This paper presents a method to acquire accurate 3D shapes of palmprint and hand by projecting full-field composite color sinusoidal fringe patterns and the corresponding color texture information. A 3D imaging system is designed to capture and process the full-field composite color fringe patterns on hand surface. Composite color fringe patterns having the optimum three fringe numbers are generated by software and projected onto the surface of human hand by a digital light processing projector. From another viewpoint, a color CCD camera captures the deformed fringe patterns and saves them for postprocessing. After compensating for the cross talk and chromatic aberration between color channels, three fringe patterns are extracted from three color channels of a captured composite color image. Wrapped phase information can be calculated from the sinusoidal fringe patterns with high precision. At the same time, the absolute phase of each pixel is determined by the optimum three-fringe selection method. After building up the relationship between absolute phase map and 3D shape data, the 3D palmprint and hand are obtained. Color texture information can be directly captured or demodulated from the captured composite fringe pattern images. Experimental results show that the proposed method and system can yield accurate 3D shape and color texture information of the palmprint and hand shape.

Promoting coordination in Norwegian health care

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Tor I. Romøren

2011-10-01

Full Text Available   Introduction: The Norwegian health care system is well organized within its two main sectors - primary health and long term care on the one hand, and hospitals and specialist services on the other. However, the relation between them lacks mediating structures.Policy practice: Enhancing coordination between primary and secondary health care has been central in Norwegian health care policy the last decade. In 2003 a committee was appointed to identify coordination problems and proposed a lot of practical and organisational recommendations. It relied on an approach challenging primary and secondary health care in shared geographical regions to take action. However, these proposals were not implemented. In 2008 a new Minister of Health and Care worked out plans under the key term "Coordination Reform". These reform plans superseded and expanded the previous policy initiatives concerning cooperation, but represented also a shift in focus to a regulative and centralised strategy, including new health legislation, structural reforms and use of economic incentives that are now about to be implemented.Discussion: The article analyses the perspectives and proposals of the previous and the recent reform initiatives in Norway and discusses them in relation to integrated care measures implemented in Denmark and Sweden.

Passive hand movements disrupt adults’ counting strategies

Directory of Open Access Journals (Sweden)

Ineke eImbo

2011-09-01

Full Text Available In the present study, we experimentally tested the role of hand motor circuits in simple-arithmetic strategies. Educated adults solved simple additions (e.g., 8+3 or simple subtractions (e.g., 11–3 while they were required to retrieve the answer from long-term memory (e.g., knowing that 8+3 = 11, to transform the problem by making an intermediate step (e.g., 8+3 = 8+2+1 = 10+1 = 11 or to count one-by-one (e.g., 8+3 = 8…9…10…11. During the process of solving the arithmetic problems, the experimenter did or did not move the participants’ hand on a 4-point matrix. The results show that passive hand movements disrupted the counting strategy while leaving the other strategies unaffected. This pattern of results is in agreement with a procedural account, showing that the involvement of hand motor circuits in adults’ mathematical abilities is reminiscent of finger counting during childhood.

Compensatory Motor Control After Stroke: An Alternative Joint Strategy for Object-Dependent Shaping of Hand Posture

OpenAIRE

Raghavan, Preeti; Santello, Marco; Gordon, Andrew M.; Krakauer, John W.

2010-01-01

Efficient grasping requires planned and accurate coordination of finger movements to approximate the shape of an object before contact. In healthy subjects, hand shaping is known to occur early in reach under predominantly feedforward control. In patients with hemiparesis after stroke, execution of coordinated digit motion during grasping is impaired as a result of damage to the corticospinal tract. The question addressed here is whether patients with hemiparesis are able to compensate for th...

Bimanual coordination positively predicts episodic memory: A combined behavioral and MRI investigation.

Science.gov (United States)

Lyle, Keith B; Dombroski, Brynn A; Faul, Leonard; Hopkins, Robin F; Naaz, Farah; Switala, Andrew E; Depue, Brendan E

2017-11-01

Some people remember events more completely and accurately than other people, but the origins of individual differences in episodic memory are poorly understood. One way to advance understanding is by identifying characteristics of individuals that reliably covary with memory performance. Recent research suggests motor behavior is related to memory performance, with individuals who consistently use a single preferred hand for unimanual actions performing worse than individuals who make greater use of both hands. This research has relied on self-reports of behavior. It is unknown whether objective measures of motor behavior also predict memory performance. Here, we tested the predictive power of bimanual coordination, an important form of manual dexterity. Bimanual coordination, as measured objectively on the Purdue Pegboard Test, was positively related to correct recall on the California Verbal Learning Test-II and negatively related to false recall. Furthermore, MRI data revealed that cortical surface area in right lateral prefrontal regions was positively related to correct recall. In one of these regions, cortical thickness was negatively related to bimanual coordination. These results suggest that individual differences in episodic memory may partially reflect morphological variation in right lateral prefrontal cortex and suggest a relationship between neural correlates of episodic memory and motor behavior. Copyright © 2017 Elsevier Inc. All rights reserved.

Thoraco-abdominal coordination and performance during uphill running at altitude.

Directory of Open Access Journals (Sweden)

Eva Bernardi

Full Text Available Running races on mountain trails at moderate-high altitude with large elevation changes throughout has become increasingly popular. During exercise at altitude, ventilatory demands increase due to the combined effects of exercise and hypoxia.To investigate the relationships between thoraco-abdominal coordination, ventilatory pattern, oxygen saturation (SpO2, and endurance performance in runners during high-intensity uphill exercise.Fifteen participants (13 males, mean age 42±9 yrs ran a "Vertical Kilometer," i.e., an uphill run involving a climb of approximately 1000 m with a slope greater than 30%. The athletes were equipped with a portable respiratory inductive plethysmography system, a finger pulse oximeter and a global positioning unit (GPS. The ventilatory pattern (ventilation (VE, tidal volume (VT, respiratory rate (RR, and VE/VT ratio, thoraco-abdominal coordination, which is represented by the phase angle (PhA, and SpO2 were evaluated at rest and during the run. Before and after the run, we assessed respiratory function, respiratory muscle strength and the occurrence of interstitial pulmonary edema by thoracic ultrasound.Two subjects were excluded from the respiratory inductive plethysmography analysis due to motion artifacts. A quadratic relationship between the slope and the PhA was observed (r = 0.995, p = 0.036. When the slope increased above 30%, the PhA increased, indicating a reduction in thoraco-abdominal coordination. The reduced thoraco-abdominal coordination was significantly related to reduced breathing efficiency (i.e., an increased VE/VT ratio; r = 0.961, p = 0.038 and SpO2 (r = -0.697, p<0.001. Lower SpO2 values were associated with lower speeds at 20%≥slope≤40% (r = 0.335, p<0.001 for horizontal and r = 0.36, p<0.001 for vertical. The reduced thoraco-abdominal coordination and consequent reduction in SpO2 were associated with interstitial pulmonary edema.Reductions in thoraco-abdominal coordination are associated

Inter-joint coordination between hips and trunk during downswings: Effects on the clubhead speed.

Science.gov (United States)

Choi, Ahnryul; Lee, In-Kwang; Choi, Mun-Taek; Mun, Joung Hwan

2016-10-01

Understanding of the inter-joint coordination between rotational movement of each hip and trunk in golf would provide basic knowledge regarding how the neuromuscular system organises the related joints to perform a successful swing motion. In this study, we evaluated the inter-joint coordination characteristics between rotational movement of the hips and trunk during golf downswings. Twenty-one right-handed male professional golfers were recruited for this study. Infrared cameras were installed to capture the swing motion. The axial rotation angle, angular velocity and inter-joint coordination were calculated by the Euler angle, numerical difference method and continuous relative phase, respectively. A more typical inter-joint coordination demonstrated in the leading hip/trunk than trailing hip/trunk. Three coordination characteristics of the leading hip/trunk reported a significant relationship with clubhead speed at impact (r joint coordination strategies have the great potential to use a biomechanical guideline to improve the golf swing performance of unskilled golfers.

Learning to breathe and sing: development of respiratory-vocal coordination in young songbirds.

Science.gov (United States)

Veit, Lena; Aronov, Dmitriy; Fee, Michale S

2011-10-01

How do animals with learned vocalizations coordinate vocal production with respiration? Songbirds such as the zebra finch learn their songs, beginning with highly variable babbling vocalizations known as subsong. After several weeks of practice, zebra finches are able to produce a precisely timed pattern of syllables and silences, precisely coordinated with expiratory and inspiratory pulses (Franz M, Goller F. J Neurobiol 51: 129-141, 2002). While respiration in adult song is well described, relatively little is known about respiratory patterns in subsong or about the processes by which respiratory and vocal patterns become coordinated. To address these questions, we recorded thoracic air sac pressure in juvenile zebra finches prior to the appearance of any consistent temporal or acoustic structure in their songs. We found that subsong contains brief inspiratory pulses (50 ms) alternating with longer pulses of sustained expiratory pressure (50-500 ms). In striking contrast to adult song, expiratory pulses often contained multiple (0-8) variably timed syllables separated by expiratory gaps and were only partially vocalized. During development, expiratory pulses became shorter and more stereotyped in duration with shorter and fewer nonvocalized parts. These developmental changes eventually resulted in the production of a single syllable per expiratory pulse and a single inspiratory pulse filling each gap, forming a coordinated sequence similar to that of adult song. To examine the role of forebrain song-control nuclei in the development of respiratory patterns, we performed pressure recordings before and after lesions of nucleus HVC (proper name) and found that this manipulation reverses the developmental trends in measures of the respiratory pattern.

Toddler hand preference trajectories predict 3-year language outcome.

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Nelson, Eliza L; Gonzalez, Sandy L; Coxe, Stefany; Campbell, Julie M; Marcinowski, Emily C; Michel, George F

2017-11-01

A growing body of work suggests that early motor experience affects development in unexpected domains. In the current study, children's hand preference for role-differentiated bimanual manipulation (RDBM) was measured at monthly intervals from 18 to 24 months of age (N = 90). At 3 years of age, children's language ability was assessed using the Preschool Language Scales 5th edition (PLS™-5). Three distinct RDBM hand preference trajectories were identified using latent class growth analysis: (1) children with a left hand preference but a moderate amount of right hand use; (2) children with a right hand preference but a moderate amount of left hand use; and (3) children with a right hand preference and only a mild amount of left hand use. Stability over time within all three trajectories indicated that children did not change hand use patterns from 18 to 24 months. Children with the greatest amount of preferred (i.e., right) hand use demonstrated higher expressive language scores compared to children in both trajectories with moderate levels of non-preferred hand use. Children with the greatest amount of right hand use also had higher scores for receptive language compared to children with a right hand preference but moderate left hand use. Results support that consistency in handedness as measured by the amount of preferred hand use is related to distal language outcomes in development. © 2017 Wiley Periodicals, Inc.

Improved nondominant hand performance on a laparoscopic virtual reality simulator after playing the Nintendo Wii.

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Middleton, Kellie K; Hamilton, Travis; Tsai, Pei-Chien; Middleton, Dana B; Falcone, John L; Hamad, Giselle

2013-11-01

Video games have been shown to improve eye-hand coordination, spatial visualization, manual dexterity, and rapid mental processing, which are important in the acquisition of laparoscopic skills. This study investigated the relationship between playing Nintendo(®) Wii™ and virtual reality (VR) laparoscopic surgery simulator performance. We hypothesized that playing the Wii would improve surgical skills performance on a VR laparoscopic simulator and hoped to elucidate which tasks, in particular, would be most beneficial for nondominant hand training. This was a single-blinded, randomized, prospective study conducted with 23 student volunteers. VR laparoscopic skills were assessed at baseline on a Simbionix LapMentor™ Surgical Simulator (Simbionix Ltd., Israel) and after the gaming period of 2 weeks. Simulator performance metrics were compared between groups using nonparametric statistics and an alpha of 0.05. Compared with the control group, the Wii-playing group demonstrated greater improvement of six measures, including accuracy on the eye-hand coordination task (p = 0.04), faster completion time (p = 0.04), decreased number of left-handed movements (p = 0.03), decreased left handed total path length (p = 0.03), decreased total number of grasping attempts (p = 0.04), and improved left-handed economy of movement (p = 0.05) for the bimanual clipping and grasping task. When comparing the number of measures improved upon by the Wii-playing group and the control group for all three tasks, the Wii-playing group consistently outperformed the control group in 18 measures compared with the control group's improvement in 6. This study further characterizes the association between video game playing and surgical performance. Improvements following the intervention were made in the most basic of surgical skills, most notably with the nondominant hand, suggesting that short-term playing of the Wii could improve bimanual dexterity and expedite the acquisition of basic

Artificial gravity reveals that economy of action determines the stability of sensorimotor coordination.

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Richard G Carson

Full Text Available BACKGROUND: When we move along in time with a piece of music, we synchronise the downward phase of our gesture with the beat. While it is easy to demonstrate this tendency, there is considerable debate as to its neural origins. It may have a structural basis, whereby the gravitational field acts as an orientation reference that biases the formulation of motor commands. Alternatively, it may be functional, and related to the economy with which motion assisted by gravity can be generated by the motor system. METHODOLOGY/PRINCIPAL FINDINGS: We used a robotic system to generate a mathematical model of the gravitational forces acting upon the hand, and then to reverse the effect of gravity, and invert the weight of the limb. In these circumstances, patterns of coordination in which the upward phase of rhythmic hand movements coincided with the beat of a metronome were more stable than those in which downward movements were made on the beat. When a normal gravitational force was present, movements made down-on-the-beat were more stable than those made up-on-the-beat. CONCLUSIONS/SIGNIFICANCE: The ubiquitous tendency to make a downward movement on a musical beat arises not from the perception of gravity, but as a result of the economy of action that derives from its exploitation.

Assessment of the environmental microbiological cross contamination following hand drying with paper hand towels or an air blade dryer.

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Margas, E; Maguire, E; Berland, C R; Welander, F; Holah, J T

2013-08-01

This study compared the potential for cross contamination of the surrounding environment resulting from two different hand-drying methods: paper towels and the use of an air blade dryer. One hundred volunteers for each method washed their hands and dried them using one of the two methods. Bacterial contamination of the surrounding environment was measured using settle plates placed on the floor in a grid pattern, air sampling and surface swabs. Both drying methods produced ballistic droplets in the immediate vicinity of the hand-drying process. The air blade dryer produced a larger number of droplets which were dispersed over a larger area. Settle plates showed increased microbial contamination in the grid squares which were affected by ballistic droplets. Using the settle plates counts, it was estimated that approx. 1.7 × 10(5) cfu more micro-organisms were left on the laboratory floor (total area approx. 17.15 m(2)) after 100 volunteers used an air blade dryer compared to when paper towels were used. The two drying methods led to different patterns of ballistic droplets and levels of microbial contamination under heavy use conditions. Whilst the increase in microbial levels in the environment is not significant if only nonpathogenic micro-organisms are spread, it may increase the risk of pathogen contamination of the environment when pathogens are occasionally present on people's hands. The study suggests that the risk of cross contamination from the washroom users to the environment and subsequent users should be considered when choosing a hand-drying method. The data could potentially give guidance following the selection of drying methods on implementing measures to minimise the risk of cross contamination. © 2013 The Society for Applied Microbiology.

Complex tasks force hand laterality and technological behaviour in naturalistically housed chimpanzees: inferences in hominin evolution.

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Mosquera, M; Geribàs, N; Bargalló, A; Llorente, M; Riba, D

2012-01-01

Clear hand laterality patterns in humans are widely accepted. However, humans only elicit a significant hand laterality pattern when performing complementary role differentiation (CRD) tasks. Meanwhile, hand laterality in chimpanzees is weaker and controversial. Here we have reevaluated our results on hand laterality in chimpanzees housed in naturalistic environments at Fundació Mona (Spain) and Chimfunshi Wild Orphanage (Zambia). Our results show that the difference between hand laterality in humans and chimpanzees is not as great as once thought. Furthermore, we found a link between hand laterality and task complexity and also an even more interesting connection: CRD tasks elicited not only the hand laterality but also the use of tools. This paper aims to turn attention to the importance of this threefold connection in human evolution: the link between CRD tasks, hand laterality, and tool use, which has important evolutionary implications that may explain the development of complex behaviour in early hominins.

Pyrolysis of Helical Coordination Polymers for Metal-Sulfide-Based Helices with Broadband Chiroptical Activity.

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Hirai, Kenji; Yeom, Bongjun; Sada, Kazuki

2017-06-27

Fabrication of chiroptical materials with broadband response in the visible light region is vital to fully realize their potential applications. One way to achieve broadband chiroptical activity is to fabricate chiral nanostructures from materials that exhibit broadband absorption in the visible light region. However, the compounds used for chiroptical materials have predominantly been limited to materials with narrowband spectral response. Here, we synthesize Ag 2 S-based nanohelices derived from helical coordination polymers. The right- and left-handed coordination helices used as precursors are prepared from l- and d-glutathione with Ag + and a small amount of Cu 2+ . The pyrolysis of the coordination helices yields right- and left-handed helices of Cu 0.12 Ag 1.94 S/C, which exhibit chiroptical activity spanning the entire visible light region. Finite element method simulations substantiate that the broadband chiroptical activity is attributed to synergistic broadband light absorption and light scattering. Furthermore, another series of Cu 0.10 Ag 1.90 S/C nanohelices are synthesized by choosing the l- or d-Glu-Cys as starting materials. The pitch length of nanohelicies is controlled by changing the peptides, which alters their chiroptical properties. The pyrolysis of coordination helices enables one to fabricate helical Ag 2 S-based materials that enable broadband chiroptical activity but have not been explored owing to the lack of synthetic routes.

The Open Method of Coordination and the New Governance Patterns in the EU

DEFF Research Database (Denmark)

Borras, Susana; Jacobsson, Kerstin

2004-01-01

tradition in the EU, and looks at how the three dominant logics of co-ordination are linked to diverse modes of hte IMC. The subsequent sections focus on teh potential impact of the OMC on the policy and politics dimensions of the EU. Theoretically inspired assumptions about policy learning and partial......The aim of this article is to establish an analytical framework for studying the impact of the open method of coordination (OMC) on three levels of political action within the EU, namely the policy, politics and polity. First, the article examines the novelties of the OMC vis-à-vis the soft law...

Different coordination and flexibility of the spine and pelvis during lateral bending between young and older adults.

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Sung, Paul S

2016-04-01

This study examined coordination of the spine and pelvis during lateral bending of the trunk in older adults. Thirty-four healthy subjects (17 young and 17 older adults) demonstrated lateral bending at a controlled speed while holding a bar at approximately 180 degrees of shoulder flexion. Kinematic data collection was completed on the thoracic spine, lumbar spine, and pelvis. The coupling angle was calculated to examine the thorax-lumbar, lumbar-pelvis, and thorax-pelvis coordination patterns. The older adults demonstrated a reduced range of motion (ROM) of the lumbar spine, while both groups revealed similar ROM in the thorax and in the pelvis. The coupling angle between the straightening and bending phases was different only for the older adults in the thorax-lumbar (23.4±8.0 vs. -1.6±4.4, p=0.004) and the lumbar-pelvis (65.4±7.2 vs. 86.1±7.8, p=0.001) coordination. However, there was no group difference in the thorax-pelvis coordination. These findings indicate that age-related changes in the lumbar region affect coordination patterns only during the bending phase. The older adults preserved a similar pattern of movement to the young adults during the straightening phase, but the coordination variability of the coupling angles was greater for the older adults than for the young adults. This movement pattern suggests that the older adults lacked consistent trunk control in an attempt to optimize lateral bending coordination. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluating EMG Feature and Classifier Selection for Application to Partial-Hand Prosthesis Control

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Adenike A. Adewuyi

2016-10-01

Full Text Available Pattern recognition-based myoelectric control of upper limb prostheses has the potential to restore control of multiple degrees of freedom. Though this control method has been extensively studied in individuals with higher-level amputations, few studies have investigated its effectiveness for individuals with partial-hand amputations. Most partial-hand amputees retain a functional wrist and the ability of pattern recognition-based methods to correctly classify hand motions from different wrist positions is not well studied. In this study, focusing on partial-hand amputees, we evaluate (1 the performance of non-linear and linear pattern recognition algorithms and (2 the performance of optimal EMG feature subsets for classification of four hand motion classes in different wrist positions for 16 non-amputees and 4 amputees. Our results show that linear discriminant analysis and linear and non-linear artificial neural networks perform significantly better than the quadratic discriminant analysis for both non-amputees and partial-hand amputees. For amputees, including information from multiple wrist positions significantly decreased error (p<0.001 but no further significant decrease in error occurred when more than 4, 2, or 3 positions were included for the extrinsic (p=0.07, intrinsic (p=0.06, or combined extrinsic and intrinsic muscle EMG (p=0.08, respectively. Finally, we found that a feature set determined by selecting optimal features from each channel outperformed the commonly used time domain (p<0.001 and time domain/autoregressive feature sets (p<0.01. This method can be used as a screening filter to select the features from each channel that provide the best classification of hand postures across different wrist positions.

Effect of task-oriented activities on hand functions, cognitive functions and self-expression of elderly patients with dementia.

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Son, Bo-Young; Bang, Yo-Soon; Hwang, Min-Ji; Oh, Eun-Ju

2017-08-01

[Purpose] This study investigates the effects of task-oriented activities on hand function, cognitive function, and self-expression of the elderly with dementia, and then identify the influencing factors on self-expression in sub-factors of dependent variables. [Subjects and Methods] Forty elderly persons were divided into two groups: intervention group (n=20) and control group (n=20). The interventions were applied to the subjects 3 times a week, 50 minutes per each time, for a total of five weeks. We measured the jamar hand dynamometer test for grip strength, the jamar hydraulic pinch gauge test for prehension test, nine-hole pegboard test for coordination test, and Loewenstein Occupational Therapy Cognitive Assessment-Geriatric Population for cognitive function, and self-expression rating scale for self-expression test. [Results] The task-oriented activities promoted hand function, cognitive function (visual perception, spatial perception, visuomotor organization, attention & concentration) and self-expression of the elderly with early dementia, and the factors influencing the self-expression were cognitive function (visual perception) and hand function (coordination). The study showed that the task-oriented program enabled self-expression by improving hand function and cognitive function. [Conclusion] This study suggested that there should be provided the task-oriented program for prevention and treatment of the elderly with early dementia in the clinical settings and it was considered that results have a value as basic data that can be verified relationship of hand function, cognitive function, and self-expression.

THE INFLUENCE OF THE EXERCISES OF GROSS AND FINE MOTOR SKILLS ON VISUO-MOTOR COORDINATION OF THE CEREBRAL PALSY CHILDREN

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Almira Mujkić

2013-09-01

Full Text Available Visuomotor coordination is reffered to eye coordination and to various parts of the body in different activities and games. The aim of the research was to establish the influence of the exercises of gross and fine motor skills on visuomotor coordination of the cerebral palsy children. The sample was the case study where a male person of 3 and a half years old was an examinee. Measuring instrument used was the Test of visuomotor coordination of the gross motor skills of the dominant hand. Data were analyzed by t-test.

Virtual Reality Glasses and "Eye-Hands Blind Technique" for Microsurgical Training in Neurosurgery.

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Choque-Velasquez, Joham; Colasanti, Roberto; Collan, Juhani; Kinnunen, Riina; Rezai Jahromi, Behnam; Hernesniemi, Juha

2018-04-01

Microsurgical skills and eye-hand coordination need continuous training to be developed and refined. However, well-equipped microsurgical laboratories are not so widespread as their setup is expensive. Herein, we present a novel microsurgical training system that requires a high-resolution personal computer screen, smartphones, and virtual reality glasses. A smartphone placed on a holder at a height of about 15-20 cm from the surgical target field is used as the webcam of the computer. A specific software is used to duplicate the video camera image. The video may be transferred from the computer to another smartphone, which may be connected to virtual reality glasses. Using the previously described training model, we progressively performed more and more complex microsurgical exercises. It did not take long to set up our system, thus saving time for the training sessions. Our proposed training model may represent an affordable and efficient system to improve eye-hand coordination and dexterity in using not only the operating microscope but also endoscopes and exoscopes. Copyright © 2018 Elsevier Inc. All rights reserved.

Coordinating talk and practical action

DEFF Research Database (Denmark)

Oshima, Sae; Streeck, Jürgen

2015-01-01

This paper investigates how talk and practical action are coordinated during one type of activity involving professional communication: the service-assessment sequence in hair salons. During this activity, a practical inspection of the haircut must be coupled with sequentially produced verbal acts....... Our analysis of four examples reveals that there is no fixed relationship between the organization of talk and practical action. Instead, people manipulate this relationship on a moment-by-moment basis, often coordinating the two into a single, integral package, or relying on one stream of action...... to achieve progress in the other. These findings imply that some multimodal activities that are brought into alignment may have their own, separate and independent procedural logic and sequencing patterns and that these can be brought into play to create or deal with constraints in each other....

Fractures and dislocations of the hand in polytrauma patients : Incidence, injury pattern and functional outcome

NARCIS (Netherlands)

Ferree, Steven; van der Vliet, Quirine M J; van Heijl, Mark; Houwert, Roderick M; Leenen, Luke P H; Hietbrink, Falco

INTRODUCTION: Injuries of the hand can cause significant functional impairment, diminished quality of life and delayed return to work. However, the incidence and functional outcome of hand injuries in polytrauma patients is currently unknown. The aim of this study was to determine the incidence,

Distinct interjoint coordination during fast alternate keystrokes in pianists with superior skill

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Shinichi eFuruya

2011-05-01

Full Text Available Musical performance requires motor skills to coordinate the movements of multiple joints in the hand and arm over a wide range of tempi. However, it is unclear whether the coordination of movement across joints would differ for musicians with different skill levels and how inter-joint coordination would vary in relation to music tempo. The present study addresses these issues by examining the kinematics and muscular activity of the hand and arm movements of professional and amateur pianists who strike two keys alternately with the thumb and little finger at various tempi. The professionals produced a smaller flexion velocity at the thumb and little finger and greater elbow pronation and supination velocity than did the amateurs. The experts also showed smaller extension angles at the metacarpo-phalangeal joint of the index and middle fingers, which were not being used to strike the keys. Furthermore, muscular activity in the extrinsic finger muscles was smaller for the experts than for the amateurs. These findings indicate that pianists with superior skill reduce the finger muscle load during keystrokes by taking advantage of differences in proximal joint motion and hand postural configuration. With an increase in tempo, the experts showed larger and smaller increases in elbow velocity and finger muscle co-activation, respectively, compared to the amateurs, highlighting skill-level-dependent differences in movement strategies for tempo adjustment. Finally, when striking as fast as possible, individual differences in the striking tempo among players were explained by their elbow velocities but not by their digit velocities. These findings suggest that pianists who are capable of faster keystrokes benefit more from proximal joint motion than do pianists who are not capable of faster keystrokes. The distinct movement strategy for tempo adjustment in pianists with superior skill would therefore ensure a wider range of musical expression.

Structural Integration and Control of Peerless Human-like Prosthetic Hand

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Dave, Ankit; Muthu, P.; Karthikraj, V.; Latha, S.

2018-04-01

Limb damage can create severe disturbance in movement and operative abilities wherein the prosthetic rehabilitation has the potential to replace function and enhance the quality of life. This paper presents a humanlike prosthetic hand using such unique design concept of hand model using artificial bones, ligaments, and tendons controlled using Arduino. Amongst various platforms available, Arduino is known for its adaptability, adoration and low cost. The design of prosthetic hand has a unique structure with all carpal, metacarpal, and phalanges which are bones of the hand. These bones are attached to each other following the pattern of human hand using the polymeric rubber as a functioning ligament. Furthermore, this structure of finger is driven by tendons attached to all fingers and passes through the ligaments working as pulley resulting in more degrees of freedom. The motor can twitch the tendons to achieve the action of fingers. Thus the servos, controlled by an Arduino, are used to regulate the movement mechanism of the prosthetic hand.

A soft robotic exomusculature glove with integrated sEMG sensing for hand rehabilitation.

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Delph, Michael A; Fischer, Sarah A; Gauthier, Phillip W; Luna, Carlos H Martinez; Clancy, Edward A; Fischer, Gregory S

2013-06-01

Stroke affects 750,000 people annually, and 80% of stroke survivors are left with weakened limbs and hands. Repetitive hand movement is often used as a rehabilitation technique in order to regain hand movement and strength. In order to facilitate this rehabilitation, a robotic glove was designed to aid in the movement and coordination of gripping exercises. This glove utilizes a cable system to open and close a patients hand. The cables are actuated by servomotors, mounted in a backpack weighing 13.2 lbs including battery power sources. The glove can be controlled in terms of finger position and grip force through switch interface, software program, or surface myoelectric (sEMG) signal. The primary control modes of the system provide: active assistance, active resistance and a preprogrammed mode. This project developed a working prototype of the rehabilitative robotic glove which actuates the fingers over a full range of motion across one degree-of-freedom, and is capable of generating a maximum 15N grip force.

Single-unit pattern generators for quadruped locomotion

DEFF Research Database (Denmark)

Morse, Gregory; Risi, Sebastian; Snyder, Charles R

2013-01-01

Legged robots can potentially venture beyond the limits of wheeled vehicles. While creating controllers for such robots by hand is possible, evolutionary algorithms are an alternative that can reduce the burden of hand-crafting robotic controllers. Although major evolutionary approaches to legged...... on a new type of neuron called a single-unit pattern generator (SUPG). The SUPG, which is indirectly encoded by a compositional pattern producing network (CPPN) evolved by HyperNEAT, produces a flexible temporal activation pattern that can be reset and repeated at any time through an explicit trigger input...

Effect of increasing energy cost on arm coordination in elite sprint swimmers.

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Komar, J; Leprêtre, P M; Alberty, M; Vantorre, J; Fernandes, R J; Hellard, P; Chollet, D; Seifert, L

2012-06-01

The purpose of this study was to analyze the changes in stroke parameters, motor organization and swimming efficiency with increasing energy cost in aquatic locomotion. Seven elite sprint swimmers performed a 6×300-m incremental swimming test. Stroke parameters (speed, stroke rate and stroke length), motor organization (arm stroke phases and arm coordination index), swimming efficiency (swimming speed squared and hand speed squared) and stroke index were calculated from aerial and underwater side-view cameras. The energy cost of locomotion was assessed by measuring oxygen consumption and blood lactate. Results showed that the increase in energy cost of locomotion was correlated to an increase in the index of coordination and stroke rate, and a decrease in stroke length (pstroke index did not change significantly with the speed increments (pstroke rate were observed, along with a decrease in stroke length, stroke index and hand speed squared with each increment, revealing an adaptation to the fatigue within the 300m. Copyright © 2011 Elsevier B.V. All rights reserved.

Embodied finger counting in children with different cultural backgrounds and hand dominance

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Liutsko L.

2017-12-01

Full Text Available Background. Embodied finger counting has been shown to have cross-cultural differences in previous studies (Lindemann, Alipour, & Fisher, 2011; Soto & Lalain, 2008. However, their results were contradictory in reference to Western populations with regard to the hand preferred: The first study showed that in Western countries — Europe and the United States — participants preferred to start with the left hand (whereas in the Middle East — Iran — they used the right hand; the second study showed that participants in France preferred the right hand. Objective. Our study aimed to observe these differences in two countries, Spain (Western Europe and Russia (Eastern Europe part, although taking into account the variety of cultural or ethnic groups who live there. Design. The observational/descriptive study, together with correlational analysis of the finger-counting pattern (from 1 to 10 used by children aged 10 to 12 who had not been taught to use their fingers for counting, considered factors of cultural origin and hand dominance. The possible effects of this action on cognition — in our case, math achievement — were considered also. Results and conclusion. The differences in the frequency of the finger-counting patterns might suggest cultural-individual differences in performance; however, the correlational analysis did not reveal that these differences were statistically significant, either for gender or for mark in math. However, hand dominance was a significant predictor of the preferred hand with which to start counting.

Anion-Dependent Exocyclic Mercury(II) Coordination Polymers of Bis-dithiamacrocycle

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Siewe, Arlette Deukam; Kim, Seul Gi; Choi, Kyu Seong [Kyungnam University, Changwon (Korea, Republic of); Lee, Shim Sung [Gyeongsang National University, Jinju (Korea, Republic of)

2014-09-15

Synthesis and structural characterization of mercury(II) halides and perchlorate complexes of bis-OS{sub 2}-Synthesis and structural characterization of mercury(II) halides and perchlorate complexes of bis-OS{sub 2}- macrocycle (L) are reported. L reacts with mercury(II) chloride and bromide to yield an isostructural 2D coordination polymers with type [Hg(L)X{sub 2}]n (1: X = Cl and 2: X = Br). In 1, each Hg atom which lies outside the cavity is six-coordinate with a distorted octahedral geometry, being bound to four adjacent ligands via monodentate Hg-S bonds and two remaining sites are occupied by two terminal chlorido ligands to form a fishnet-like 2D structure. When reacting with mercury(II) iodide, L afforded a 1D coordination polymer [Hg{sub 2}(L)I{sub 4}]·CHCl{sub 3}n in which each exocyclic Hg atom is four-coordinate, being bound to two sulfur donors from different ligands doubly bridging the ligand molecules in a head-to-tail mode. The coordination sphere in 3 is completed by two iodo terminal ligands, adopting a distorted tetrahedral geometry. On reacting with mercury(II) perchlorate, L forms solvent-coordinated 1D coordination polymer ([Hg{sub 2}(L)(DMF){sub 6}](ClO{sub 4}){sub 4}·2DMF)n instead of the anion-coordination. In 4, the Hg atom is five-coordinate, being bound to two sulfur donors from two different ligands doubly bridging the ligand molecules in a side-by-side mode to form a ribbon-like 1D structure.. The three remaining coordination sites in 4 are completed by three DMF molecules in a monodentate manner. Consequently, the different structures and connectivity patterns for the observed exocyclic coordination polymers depending on the anions used are influenced not only by the coordination ability of the anions but also by anion sizes macrocycle (L) are reported. L reacts with mercury(II) chloride and bromide to yield an isostructural 2D coordination polymers with type [Hg(L)X{sub 2}]n (1: X = Cl and 2: X = Br). In 1, each Hg atom which lies

Effects of action observation therapy on hand dexterity and EEG-based cortical activation patterns in patients with post-stroke hemiparesis.

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Kuk, Eun-Ju; Kim, Jong-Man; Oh, Duck-Won; Hwang, Han-Jeong

2016-10-01

Previous reports have suggested that action observation training (AOT) is beneficial in enhancing the early learning of new motor tasks; however, EEG-based investigation has received little attention for AOT. The purpose of this study was to illustrate the effects of AOT on hand dexterity and cortical activation in patients with post-stroke hemiparesis. Twenty patients with post-stroke hemiparesis were randomly divided into either the experimental group (EG) or control group (CG), with 10 patients in each group. Prior to the execution of motor tasks (carrying wooden blocks from one box to another), subjects in the EG and CG observed a video clip displaying the execution of the same motor task and pictures showing landscapes, respectively. Outcome measures included the box and block test (BBT) to evaluate hand dexterity and EEG-based brain mapping to detect changes in cortical activation. The BBT scores (EG: 20.50 ± 6.62 at pre-test and 24.40 ± 5.42 at post-test; CG: 20.20 ± 6.12 at pre-test and 20.60 ± 7.17 at post-test) revealed significant main effects for the time and group and significant time-by-group interactions (p < 0.05). For the subjects in the EG, topographical representations obtained with the EEG-based brain mapping system were different in each session of the AOT and remarkable changes occurred from the 2nd session of AOT. Furthermore, the middle frontal gyrus was less active at post-test than at pre-test. These findings support that AOT may be beneficial in altering cortical activation patterns and hand dexterity.

Impact of selected family socio-economic factors on coordinational predispositions of children

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Jarosław Domaradzki

2011-03-01

Full Text Available Introduction: Biological growth of children is genetically determined but there are a lot of factors modifying trends of growth. Among them the most important seems to be parents’ education and number of children in family – socio-economical factors. Factors don’t affect organism individually. Interactions between them can increase or decrease. So the aim of the work was to estimate the influence of socio-economic factors like parents’ education and number of children in family on coordinational traits of children aged 10–11. Material and methods: 199 children aged 10-11 underwent medical examination in 2008 in Polkowice and data collected were used in this study.. Information on parents’ education and number of children was used to divide children into four groups: lower education and 3 or more children in family, lower education and less than 3 children in family, higher education and more than 3 children in family and higher education and less than 3 children in family. Three coordinational traits were measured: short time memory, precision of hand and speed movement of the hand. MANOVA test was used to estimate differences between groups and to check interactions between factors. Results: From among 4 groups of boys, these from the worst socio-economic status of family received the worst results in all three tests. Differences between them and the rest of the groups were statistically significant. Differences between the rest of the groups were not statistically significant. In the girls groups children from families with higher parents’ education received statistically significant better results in test of memory. There were not differences between all 4 groups in precision of the hand test. Girls from family with higher parents’ education and 3 or more children in family received the best results in speed of the hand test. Conclusions: Boys are the gender more eco-sensitive. The family with more than 2 children in family

One digit interruption: the altered force patterns during functionally cylindrical grasping tasks in patients with trigger digits.

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Po-Tsun Chen

Full Text Available Most trigger digit (TD patients complain that they have problems using their hand in daily or occupational tasks due to single or multiple digits being affected. Unfortunately, clinicians do not know much about how this disease affects the subtle force coordination among digits during manipulation. Thus, this study examined the differences in force patterns during cylindrical grasp between TD and healthy subjects. Forty-two TD patients with single digit involvement were included and sorted into four groups based on the involved digits, including thumb, index, middle and ring fingers. Twelve healthy subjects volunteered as healthy controls. Two testing tasks, holding and drinking, were performed by natural grasping with minimal forces. The relations between the force of the thumb and each finger were examined by Pearson correlation coefficients. The force amount and contribution of each digit were compared between healthy controls and each TD group by the independent t test. The results showed all TD groups demonstrated altered correlation patterns of the thumb relative to each finger. Larger forces and higher contributions of the index finger were found during holding by patients with index finger involved, and also during drinking by patients with affected thumb and with affected middle finger. Although no triggering symptom occurred during grasping, the patients showed altered force patterns which may be related to the role of the affected digit in natural grasping function. In conclusion, even if only one digit was affected, the subtle force coordination of all the digits was altered during simple tasks among the TD patients. This study provides the information for the future studies to further comprehend the possible injuries secondary to the altered finger coordination and also to adopt suitable treatment strategies.

One digit interruption: the altered force patterns during functionally cylindrical grasping tasks in patients with trigger digits.

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Chen, Po-Tsun; Lin, Chien-Ju; Jou, I-Ming; Chieh, Hsiao-Feng; Su, Fong-Chin; Kuo, Li-Chieh

2013-01-01

Most trigger digit (TD) patients complain that they have problems using their hand in daily or occupational tasks due to single or multiple digits being affected. Unfortunately, clinicians do not know much about how this disease affects the subtle force coordination among digits during manipulation. Thus, this study examined the differences in force patterns during cylindrical grasp between TD and healthy subjects. Forty-two TD patients with single digit involvement were included and sorted into four groups based on the involved digits, including thumb, index, middle and ring fingers. Twelve healthy subjects volunteered as healthy controls. Two testing tasks, holding and drinking, were performed by natural grasping with minimal forces. The relations between the force of the thumb and each finger were examined by Pearson correlation coefficients. The force amount and contribution of each digit were compared between healthy controls and each TD group by the independent t test. The results showed all TD groups demonstrated altered correlation patterns of the thumb relative to each finger. Larger forces and higher contributions of the index finger were found during holding by patients with index finger involved, and also during drinking by patients with affected thumb and with affected middle finger. Although no triggering symptom occurred during grasping, the patients showed altered force patterns which may be related to the role of the affected digit in natural grasping function. In conclusion, even if only one digit was affected, the subtle force coordination of all the digits was altered during simple tasks among the TD patients. This study provides the information for the future studies to further comprehend the possible injuries secondary to the altered finger coordination and also to adopt suitable treatment strategies.

Is Hand Selection Modulated by Cognitive-perceptual Load?

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Liang, Jiali; Wilkinson, Krista; Sainburg, Robert L

2018-01-15

Previous studies proposed that selecting which hand to use for a reaching task appears to be modulated by a factor described as "task difficulty". However, what features of a task might contribute to greater or lesser "difficulty" in the context of hand selection decisions has yet to be determined. There has been evidence that biomechanical and kinematic factors such as movement smoothness and work can predict patterns of selection across the workspace, suggesting a role of predictive cost analysis in hand-selection. We hypothesize that this type of prediction for hand-selection should recruit substantial cognitive resources and thus should be influenced by cognitive-perceptual loading. We test this hypothesis by assessing the role of cognitive-perceptual loading on hand selection decisions, using a visual search task that presents different levels of difficulty (cognitive-perceptual load), as established in previous studies on overall response time and efficiency of visual search. Although the data are necessarily preliminary due to small sample size, our data suggested an influence of cognitive-perceptual load on hand selection, such that the dominant hand was selected more frequently as cognitive load increased. Interestingly, cognitive-perceptual loading also increased cross-midline reaches with both hands. Because crossing midline is more costly in terms of kinematic and kinetic factors, our findings suggest that cognitive processes are normally engaged to avoid costly actions, and that the choice not-to-cross midline requires cognitive resources. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Performance Comparison Between FEDERICA Hand and LARM Hand

OpenAIRE

Carbone, Giuseppe; Rossi, Cesare; Savino, Sergio

2015-01-01

This paper describes two robotic hands that have been\\ud developed at University Federico II of Naples and at the\\ud University of Cassino. FEDERICA Hand and LARM Hand\\ud are described in terms of design and operational features.\\ud In particular, careful attention is paid to the differences\\ud between the above-mentioned hands in terms of transmission\\ud systems. FEDERICA Hand uses tendons and pulleys\\ud to drive phalanxes, while LARM Hand uses cross four-bar\\ud linkages. Results of experime...

Quantifying coordination among the rearfoot, midfoot, and forefoot segments during running.

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Takabayashi, Tomoya; Edama, Mutsuaki; Yokoyama, Erika; Kanaya, Chiaki; Kubo, Masayoshi

2018-03-01

Because previous studies have suggested that there is a relationship between injury risk and inter-segment coordination, quantifying coordination between the segments is essential. Even though the midfoot and forefoot segments play important roles in dynamic tasks, previous studies have mostly focused on coordination between the shank and rearfoot segments. This study aimed to quantify coordination among rearfoot, midfoot, and forefoot segments during running. Eleven healthy young men ran on a treadmill. The coupling angle, representing inter-segment coordination, was calculated using a modified vector coding technique. The coupling angle was categorised into four coordination patterns. During the absorption phase, rearfoot-midfoot coordination in the frontal planes was mostly in-phase (rearfoot and midfoot eversion with similar amplitudes). The present study found that the eversion of the midfoot with respect to the rearfoot was comparable in magnitude to the eversion of the rearfoot with respect to the shank. A previous study has suggested that disruption of the coordination between the internal rotation of the shank and eversion of the rearfoot leads to running injuries such as anterior knee pain. Thus, these data might be used in the future to compare to individuals with foot deformities or running injuries.

Back to basics: hand hygiene and surgical hand antisepsis.

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Spruce, Lisa

2013-11-01

Health care-associated infections (HAIs) are a significant issue in the United States and throughout the world, but following proper hand hygiene practices is the most effective and least expensive way to prevent HAIs. Hand hygiene is inexpensive and protects patients and health care personnel alike. The four general types of hand hygiene that should be performed in the perioperative environment are washing hands that are visibly soiled, hand hygiene using alcohol-based products, surgical hand scrubs, and surgical hand scrubs using an alcohol-based surgical hand rub product. Barriers to proper hand hygiene may include not thinking about it, forgetting, skin irritation, a lack of role models, or a lack of a safety culture. One strategy for improving hand hygiene practices is monitoring hand hygiene as part of a quality improvement project, but the most important aspect for perioperative team members is to set an example for other team members by following proper hand hygiene practices and reminding each other to perform hand hygiene. Copyright © 2013 AORN, Inc. Published by Elsevier Inc. All rights reserved.

The volume of fluid method in spherical coordinates

NARCIS (Netherlands)

Janse, A.M.C.; Janse, A.M.C.; Dijk, P.E.; Kuipers, J.A.M.

2000-01-01

The volume of fluid (VOF) method is a numerical technique to track the developing free surfaces of liquids in motion. This method can, for example, be applied to compute the liquid flow patterns in a rotating cone reactor. For this application a spherical coordinate system is most suited. The novel

Multiple faces of contemporary hand knitting

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Pavko-Čuden, A.

2017-10-01

Knitting and crocheting are traditional textile techniques with great significance both in history and modern times. Similar to other textile techniques, knitting has developed into a diversified industrial sector, comprising the production of knitted fabrics, knitwear, hosiery and fashion accessories. At the same time, contemporary knitting and crocheting became hobbies as well as arts-and-crafts activities, extending to various areas of work and leisure. Historical and traditional ethnic knitting and crocheting patterns keep inspiring designers’ collections and also other industrial products. Not so long ago, knitting was seen as an ordinary and unchanging indoor activity and, in its domestic history, it was the preserve of older women making products of dainty work and taste. Today, knitting deals with urban population of all classes. The popularity of leisure hand knitting is increasing; moreover, hand knitting is becoming more and more widespread among young people. With the emergence of artistic and handicraft markets, hand-knitting and crocheting developed into a profitable market activity. Positive effects of hand knitting have become increasingly important - from generating creativity and innovativeness, through knitting and socializing in groups, to medical and therapeutic effects as well as social and global connections. Yarn bombing, yarn storming or graffiti knitting has been used to describe urban social practices of knitted objects placed, or tagged, in public spaces. Knitting became means of communication, artistic and social expression and statement. The advantage of hand knitting is its mobility. One can knit almost everywhere, and for hand knitting, only a ball of yarn and knitting needles are required. Handknitted products have nice touch, they are custom-made and therefore personalized.

Fine motor skills in South African children with symptoms of ADHD: influence of subtype, gender, age, and hand dominance

Directory of Open Access Journals (Sweden)

Meyer Anneke

2006-10-01

Full Text Available Abstract Background Motor problems, often characterised as clumsiness or poor motor coordination, have been associated with ADHD in addition to the main symptom groups of inattention, impulsiveness, and overactivity. The problems addressed in this study were: (1 Are motor problems associated with ADHD symptoms, also in African cultures? (2 Are there differences in motor skills among the subtypes with ADHD symptoms? (3 Are there gender differences? (4 Is there an effect of age? (5 Are there differences in performance between the dominant and non-dominant hand? Method A total of 528 children (264 classified as having symptoms of ADHD and 264 matched comparisons of both genders and from seven different South African ethnic groups participated in the study. They were assessed with three simple, easy to administer instruments which measure various functions of motor speed and eye-hand coordination: The Grooved Pegboard, the Maze Coordination Task, and the Finger Tapping Test. The results were analysed as a function of subtype, gender, age, and hand dominance. Results The findings indicate that children with symptoms of ADHD performed significantly poorer on the Grooved Pegboard and Motor Coordination Task, but not on the Finger Tapping Test than their comparisons without ADHD symptoms. The impairment was most severe for the subtype with symptoms of ADHD-C (combined and less severe for the subtypes with symptoms of ADHD-PI (predominantly inattentive and ADHD-HI (predominantly hyperactive/impulsive. With few exceptions, both genders were equally affected while there were only slight differences in performance between the dominant and non-dominant hand. The deficiencies in motor control were mainly confined to the younger age group (6 – 9 yr. Conclusion An association between the symptoms of ADHD and motor problems was demonstrated in terms of accuracy and speed in fairly complex tasks, but not in simple motor tests of speed. This deficiency is found

On the road to a neuroprosthetic hand: a novel hand grasp orthosis based on functional electrical stimulation.

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Leeb, Robert; Gubler, Miguel; Tavella, Michele; Miller, Heather; Del Millan, Jose R

2010-01-01

To patients who have lost the functionality of their hands as a result of a severe spinal cord injury or brain stroke, the development of new techniques for grasping is indispensable for reintegration and independency in daily life. Functional Electrical Stimulation (FES) of residual muscles can reproduce the most dominant grasping tasks and can be initialized by brain signals. However, due to the very complex hand anatomy and current limitations in FES-technology with surface electrodes, these grasp patterns cannot be smoothly executed. In this paper, we present an adaptable passive hand orthosis which is capable of producing natural and smooth movements when coupled with FES. It evenly synchronizes the grasping movements and applied forces on all fingers, allowing for naturalistic gestures and functional grasps of everyday objects. The orthosis is also equipped with a lock, which allows it to remain in the desired position without the need for long-term stimulation. Furthermore, we quantify improvements offered by the orthosis compare them with natural grasps on healthy subjects.

An Intelligent Inference System for Robot Hand Optimal Grasp Preshaping

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Cabbar Veysel Baysal

2010-11-01

Full Text Available This paper presents a novel Intelligent Inference System (IIS for the determination of an optimum preshape for multifingered robot hand grasping, given object under a manipulation task. The IIS is formed as hybrid agent architecture, by the synthesis of object properties, manipulation task characteristics, grasp space partitioning, lowlevel kinematical analysis, evaluation of contact wrench patterns via fuzzy approximate reasoning and ANN structure for incremental learning. The IIS is implemented in software with a robot hand simulation.

Stiff Hands

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... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Stiff Hands Email to a friend * required fields ...

Hand Infections

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... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Hand Infections Email to a friend * required fields ...

Exercise increases human skeletal muscle insulin sensitivity via coordinated increases in microvascular perfusion and molecular signaling

DEFF Research Database (Denmark)

Sjøberg, Kim Anker; Frøsig, Christian; Kjøbsted, Rasmus

2017-01-01

and increased similarly in both legs during the clamp and L-NMMA had no effect on these insulin-stimulated signaling pathways. Therefore, acute exercise increases insulin sensitivity of muscle by a coordinated increase in insulin-stimulated microvascular perfusion and molecular signaling at the level of TBC1D4...... and glycogen synthase in muscle. This secures improved glucose delivery on the one hand and increased ability to take up and dispose of the delivered glucose on the other hand....

Passive hand movements disrupt adults' counting strategies.

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Imbo, Ineke; Vandierendonck, André; Fias, Wim

2011-01-01

In the present study, we experimentally tested the role of hand motor circuits in simple-arithmetic strategies. Educated adults solved simple additions (e.g., 8 + 3) or simple subtractions (e.g., 11 - 3) while they were required to retrieve the answer from long-term memory (e.g., knowing that 8 + 3 = 11), to transform the problem by making an intermediate step (e.g., 8 + 3 = 8 + 2 + 1 = 10 + 1 = 11) or to count one-by-one (e.g., 8 + 3 = 8…9…10…11). During the process of solving the arithmetic problems, the experimenter did or did not move the participants' hand on a four-point matrix. The results show that passive hand movements disrupted the counting strategy while leaving the other strategies unaffected. This pattern of results is in agreement with a procedural account, showing that the involvement of hand motor circuits in adults' mathematical abilities is reminiscent of finger counting during childhood.

The Model of Coordination of Communication Channels for Small Tourist Communities

Directory of Open Access Journals (Sweden)

Jelena VASKOVIĆ

2013-12-01

Full Text Available By including e-business, small tourist communities were allowed, apart from their classic offers, to appear on the global market, but that caused the need for automation and coordination of booking capacity tasks. Advertising and booking in these communities are performed by a conventional agency arrangement, the Internet, mobile services or by tourists themselves upon their arrival in the local community where they can reserve the accommodation. The possibility of booking accommodation capacities in many ways creates additional benefits for considerable usage of excess capacity, but as a side effect there is a problem of coordination of communication channels in order to avoid double-booking. On the other hand, the local administration has a problem with the registration and the payment of the tourist tax, particularly if the tourists do not stay long. With the automation and coordination of communication channels, conflicts can be completely avoided, and the reservation system informs all interested parties and reports to the local administration.

Look Together: Analyzing Gaze Coordination with Epistemic Network Analysis

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Sean eAndrist

2015-07-01

Full Text Available When conversing and collaborating in everyday situations, people naturally and interactively align their behaviors with each other across various communication channels, including speech, gesture, posture, and gaze. Having access to a partner's referential gaze behavior has been shown to be particularly important in achieving collaborative outcomes, but the process in which people's gaze behaviors unfold over the course of an interaction and become tightly coordinated is not well understood. In this paper, we present work to develop a deeper and more nuanced understanding of coordinated referential gaze in collaborating dyads. We recruited 13 dyads to participate in a collaborative sandwich-making task and used dual mobile eye tracking to synchronously record each participant's gaze behavior. We used a relatively new analysis technique—epistemic network analysis—to jointly model the gaze behaviors of both conversational participants. In this analysis, network nodes represent gaze targets for each participant, and edge strengths convey the likelihood of simultaneous gaze to the connected target nodes during a given time-slice. We divided collaborative task sequences into discrete phases to examine how the networks of shared gaze evolved over longer time windows. We conducted three separate analyses of the data to reveal (1 properties and patterns of how gaze coordination unfolds throughout an interaction sequence, (2 optimal time lags of gaze alignment within a dyad at different phases of the interaction, and (3 differences in gaze coordination patterns for interaction sequences that lead to breakdowns and repairs. In addition to contributing to the growing body of knowledge on the coordination of gaze behaviors in joint activities, this work has implications for the design of future technologies that engage in situated interactions with human users.

Interpersonal movement coordination in jointly moving a rocking board

NARCIS (Netherlands)

Bosga, J.; Meulenbroek, R.G.J.; Cuijpers, R.H.

2010-01-01

In this study, we investigate how two persons (dyads) coordinate their movements when performing cyclical motion patterns on a rocking board. In keeping with the Leading Joint Hypothesis (Dounskaia, 2005), the movement dynamics of the collaborating participants were expected to display features of a

Temporary Nerve Block at Selected Digits Revealed Hand Motor Deficits in Grasping Tasks

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Aude Carteron

2016-11-01

Full Text Available Peripheral sensory feedback plays a crucial role in ensuring correct motor execution throughout hand grasp control. Previous studies utilized local anesthesia to deprive somatosensory feedback in the digits or hand, observations included sensorimotor deficits at both corticospinal and peripheral levels. However, the questions of how the disturbed and intact sensory input integrate and interact with each other to assist the motor program execution, and whether the motor coordination based on motor output variability between affected and non-affected elements (e.g., digits becomes interfered by the local sensory deficiency, have not been answered. The current study aims to investigate the effect of peripheral deafferentation through digital nerve blocks at selective digits on motor performance and motor coordination in grasp control. Our results suggested that the absence of somatosensory information induced motor deficits in hand grasp control, as evidenced by reduced maximal force production ability in both local and non-local digits, impairment of force and moment control during object lift and hold, and attenuated motor synergies in stabilizing task performance variables, namely the tangential force and moment of force. These findings implied that individual sensory input is shared across all the digits and the disturbed signal from local sensory channel(s has a more comprehensive impact on the process of the motor output execution in the sensorimotor integration process. Additionally, a feedback control mechanism with a sensation-based component resides in the formation process for the motor covariation structure.

Improving care coordination using organisational routines.

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Prætorius, Thim

2016-01-01

The purpose of this paper is to systematically apply theory of organisational routines to standardised care pathways. The explanatory power of routines is used to address open questions in the care pathway literature about their coordinating and organising role, the way they change and can be replicated, the way they are influenced by the organisation and the way they influence health care professionals. Theory of routines is systematically applied to care pathways in order to develop theoretically derived propositions. Care pathways mirror routines by being recurrent, collective and embedded and specific to an organisation. In particular, care pathways resemble standard operating procedures that can give rise to recurrent collective action patterns. In all, 11 propositions related to five categories are proposed by building on these insights: care pathways and coordination, change, replication, the organisation and health care professionals. Research limitations/implications - The paper is conceptual and uses care pathways as illustrative instances of hospital routines. The propositions provide a starting point for empirical research. The analysis highlights implications that health care professionals and managers have to consider in relation to coordination, change, replication, the way the organisation influences care pathways and the way care pathways influence health care professionals. Originality/value - Theory on organisational routines offers fundamental, yet unexplored, insights into hospital processes, including in particular care coordination.

Hand Dominance and Age Have Interactive Effects on Motor Cortical Representations

OpenAIRE

Bernard, Jessica A.; Seidler, Rachael D.

2012-01-01

Older adults exhibit more bilateral motor cortical activity during unimanual task performance than young adults. Interestingly, a similar pattern is seen in young adults with reduced hand dominance. However, older adults report stronger hand dominance than young adults, making it unclear how handedness is manifested in the aging motor cortex. Here, we investigated age differences in the relationships between handedness, motor cortical organization, and interhemispheric communication speed. We...

Costing the Australian National Hand Hygiene Initiative.

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Page, K; Barnett, A G; Campbell, M; Brain, D; Martin, E; Fulop, N; Graves, N

2014-11-01

The Australian National Hand Hygiene Initiative (NHHI) is a major patient safety programme co-ordinated by Hand Hygiene Australia (HHA) and funded by the Australian Commission for Safety and Quality in Health Care. The annual costs of running this programme need to be understood to know the cost-effectiveness of a decision to sustain it as part of health services. To estimate the annual health services cost of running the NHHI; the set-up costs are excluded. A health services perspective was adopted for the costing and collected data from the 50 largest public hospitals in Australia that implemented the initiative, covering all states and territories. The costs of HHA, the costs to the state-level infection-prevention groups, the costs incurred by each acute hospital, and the costs for additional alcohol-based hand rub are all included. The programme cost AU$5.56 million each year (US$5.76, £3.63 million). Most of the cost is incurred at the hospital level (65%) and arose from the extra time taken for auditing hand hygiene compliance and doing education and training. On average, each infection control practitioner spent 5h per week on the NHHI, and the running cost per annum to their hospital was approximately AU$120,000 in 2012 (US$124,000, £78,000). Good estimates of the total costs of this programme are fundamental to understanding the cost-effectiveness of implementing the NHHI. This paper reports transparent costing methods, and the results include their uncertainty. Copyright © 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Integrated, multidisciplinary care for hand eczema: design of a randomized controlled trial and cost-effectiveness study

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Boot Cécile RL

2009-12-01

Full Text Available Abstract Background The individual and societal burden of hand eczema is high. Literature indicates that moderate to severe hand eczema is a disease with a poor prognosis. Many patients are hampered in their daily activities, including work. High costs are related to high medical consumption, productivity loss and sick leave. Usual care is suboptimal, due to a lack of optimal instruction and coordination of care, and communication with the general practitioner/occupational physician and people involved at the workplace. Therefore, an integrated, multidisciplinary intervention involving a dermatologist, a care manager, a specialized nurse and a clinical occupational physician was developed. This paper describes the design of a study to investigate the effectiveness and cost-effectiveness of integrated care for hand eczema by a multidisciplinary team, coordinated by a care manager, consisting of instruction on avoiding relevant contact factors, both in the occupational and in the private environment, optimal skin care and treatment, compared to usual, dermatologist-led care. Methods The study is a multicentre, randomized, controlled trial with an economic evaluation alongside. The study population consists of patients with chronic, moderate to severe hand eczema, who visit an outpatient clinic of one of the participating 5 (three university and two general hospitals. Integrated, multidisciplinary care, coordinated by a care manager, including allergo-dermatological evaluation by a dermatologist, occupational intervention by a clinical occupational physician, and counselling by a specialized nurse on optimizing topical treatment and skin care will be compared with usual care by a dermatologist. The primary outcome measure is the cumulative difference in reduction of the clinical severity score HECSI between the groups. Secondary outcome measures are the patient's global assessment, specific quality of life with regard to the hands, generic quality

Hands-On Experiences in Deploying Cost-Effective Ambient-Assisted Living Systems.

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Dasios, Athanasios; Gavalas, Damianos; Pantziou, Grammati; Konstantopoulos, Charalampos

2015-06-18

Older adults' preferences to remain independent in their own homes along with the high costs of nursing home care have motivated the development of Ambient Assisted Living (AAL) technologies which aim at improving the safety, health conditions and wellness of the elderly. This paper reports hands-on experiences in designing, implementing and operating UbiCare, an AAL based prototype system for elderly home care monitoring. The monitoring is based on the recording of environmental parameters like temperature and light intensity as well as micro-level incidents which allows one to infer daily activities like moving, sitting, sleeping, usage of electrical appliances and plumbing components. The prototype is built upon inexpensive, off-the-shelf hardware (e.g., various sensors, Arduino microcontrollers, ZigBee-compatible wireless communication modules) and license-free software, thereby ensuring low system deployment costs. The network comprises nodes placed in a house's main rooms or mounted on furniture, one wearable node, one actuator node and a centralized processing element (coordinator). Upon detecting significant deviations from the ordinary activity patterns of individuals and/or sudden falls, the system issues automated alarms which may be forwarded to authorized caregivers via a variety of communication channels. Furthermore, measured environmental parameters and activity incidents may be monitored through standard web interfaces.

Hands-On Experiences in Deploying Cost-Effective Ambient-Assisted Living Systems

Directory of Open Access Journals (Sweden)

Athanasios Dasios

2015-06-01

Full Text Available Older adults’ preferences to remain independent in their own homes along with the high costs of nursing home care have motivated the development of Ambient Assisted Living (AAL technologies which aim at improving the safety, health conditions and wellness of the elderly. This paper reports hands-on experiences in designing, implementing and operating UbiCare, an AAL based prototype system for elderly home care monitoring. The monitoring is based on the recording of environmental parameters like temperature and light intensity as well as micro-level incidents which allows one to infer daily activities like moving, sitting, sleeping, usage of electrical appliances and plumbing components. The prototype is built upon inexpensive, off-the-shelf hardware (e.g., various sensors, Arduino microcontrollers, ZigBee-compatible wireless communication modules and license-free software, thereby ensuring low system deployment costs. The network comprises nodes placed in a house’s main rooms or mounted on furniture, one wearable node, one actuator node and a centralized processing element (coordinator. Upon detecting significant deviations from the ordinary activity patterns of individuals and/or sudden falls, the system issues automated alarms which may be forwarded to authorized caregivers via a variety of communication channels. Furthermore, measured environmental parameters and activity incidents may be monitored through standard web interfaces.

Mechanical design of a shape memory alloy actuated prosthetic hand.

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De Laurentis, Kathryn J; Mavroidis, Constantinos

2002-01-01

This paper presents the mechanical design for a new five fingered, twenty degree-of-freedom dexterous hand patterned after human anatomy and actuated by Shape Memory Alloy artificial muscles. Two experimental prototypes of a finger, one fabricated by traditional means and another fabricated by rapid prototyping techniques, are described and used to evaluate the design. An important aspect of the Rapid Prototype technique used here is that this multi-articulated hand will be fabricated in one step, without requiring assembly, while maintaining its desired mobility. The use of Shape Memory Alloy actuators combined with the rapid fabrication of the non-assembly type hand, reduce considerably its weight and fabrication time. Therefore, the focus of this paper is the mechanical design of a dexterous hand that combines Rapid Prototype techniques and smart actuators. The type of robotic hand described in this paper can be utilized for applications requiring low weight, compactness, and dexterity such as prosthetic devices, space and planetary exploration.

A synergy-driven approach to a myoelectric hand.

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Godfrey, S B; Ajoudani, A; Catalano, M; Grioli, G; Bicchi, A

2013-06-01

In this paper, we present the Pisa/IIT SoftHand with myoelectric control as a synergy-driven approach for a prosthetic hand. Commercially available myoelectric hands are more expensive, heavier, and less robust than their body-powered counterparts; however, they can offer greater freedom of motion and a more aesthetically pleasing appearance. The Pisa/IIT SoftHand is built on the motor control principle of synergies through which the immense complexity of the hand is simplified into distinct motor patterns. As the SoftHand grasps, it follows a synergistic path with built-in flexibility to allow grasping of a wide variety of objects with a single motor. Here we test, as a proof-of-concept, 4 myoelectric controllers: a standard controller in which the EMG signal is used only as a position reference, an impedance controller that determines both position and stiffness references from the EMG input, a standard controller with vibrotactile force feedback, and finally a combined vibrotactile-impedance (VI) controller. Four healthy subjects tested the control algorithms by grasping various objects. All controllers were sufficient for basic grasping, however the impedance and vibrotactile controllers reduced the physical and cognitive load on the user, while the combined VI mode was the easiest to use of the four. While these results need to be validated with amputees, they suggest a low-cost, robust hand employing hardware-based synergies is a viable alternative to traditional myoelectric prostheses.

Does a not-so-recent ankle sprain influence interjoint coordination during walking?

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Dedieu, Philippe; Chamoun, Rima; Lacaud, Guilhaume; Moulinat, Thibault; Queron, Maxime; Zanone, Pier-Giorgio

2017-12-01

Ankle sprains are common joint injuries in daily and sports activities, whose underlying mechanisms have been amply studied. If joint structures are directly damaged, neuromuscular activity can be affected, particularly in the time domain. This study aims to establish whether previous ankle injury correlates with changes in the inter-joint synergy of the entire lower limb and in the muscle activity pattern during walking. Three-dimensional walking-gait analysis was conducted on twenty-four adults. Ten of them had never suffered from ankle sprain; fourteen had suffered from ankle sprain at least once during the three preceding years. Continuous Relative Phase (CRP) between the moving limbs assessed inter-joint coordination, and muscular activity was recorded by EMG. CRP between ankle and knee and between ankle and hip indicates that both joints moved in tight synchronization in the same direction on the injured side, whereas there was a time lag between joints on the healthy side for each sprained participants or on both side for the control group. Start-time and/or duration of muscular activity of tibialis anterior, soleus and peroneus longus occurred earlier and were longer on the injured side, respectively. Our findings suggest that ankle sprain modifies inter-joint coordination and muscular activity of the injured limb, inducing not an entirely new pattern of coordination but an alteration of the existing pattern. CRP revealed slight modifications in the extant inter-joint coordination which may not be captured by other kinematic variables, which opens perspectives on therapy and relapse prevention. Copyright © 2017 Elsevier Ltd. All rights reserved.

Insights into workplace Return to Work Coordinator training: An Australian perspective.

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Bohatko-Naismith, Joanna; Guest, Maya; Rivett, Darren A; James, Carole

2016-09-27

Following brief training, an Australian workplace Return to Work (RTW) Coordinator is expected to provide information to the injured worker, liaise with key stakeholders and maintain workplace policies and procedures in accordance with legislative requirements. The aim of this study was to provide insights into the experiences and perceptions of the Australian Workplace RTW Coordinator in relation to current training practices and to identify any existing inadequacies within the available training. Twenty-five workplace RTW Coordinators from five Australian states participated in six focus groups.Participants with a minimum of two years' experience as a workplace RTW Coordinator and involved with the development and implementation of workplace policies and procedures, were included in the study. Thematic analysis was performed to identity meaningful themes and patterns. The findings highlighted specific training requirements and additional support mechanisms recommended by current workplace RTW Coordinators. Four key themes clearly emerged: inadequate training; irrelevant content; the need for specialised trainers; and network support services. RTW Coordinators require effective training and support to ensure the appropriate and timely delivery of services to all stakeholders involved in the RTW process. The results of this study may inform future training practices for RTW Coordinators.

Near-infrared image formation and processing for the extraction of hand veins

Science.gov (United States)

Bouzida, Nabila; Hakim Bendada, Abdel; Maldague, Xavier P.

2010-10-01

The main objective of this work is to extract the hand vein network using a non-invasive technique in the near-infrared region (NIR). The visualization of the veins is based on a relevant feature of the blood in relation with certain wavelengths of the electromagnetic spectrum. In the present paper, we first introduce the image formation in the NIR spectral band. Then, the acquisition system will be presented as well as the method used for the image processing in order to extract the vein signature. Extractions of this pattern on the finger, on the wrist and on the dorsal hand are achieved after exposing the hand to an optical stimulation by reflection or transmission of light. We present meaningful results of the extracted vein pattern demonstrating the utility of the method for a clinical application like the diagnosis of vein disease, of primitive varicose vein and also for applications in vein biometrics.

Hand Gesture Modeling and Recognition for Human and Robot Interactive Assembly Using Hidden Markov Models

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Fei Chen

2015-04-01

Full Text Available Gesture recognition is essential for human and robot collaboration. Within an industrial hybrid assembly cell, the performance of such a system significantly affects the safety of human workers. This work presents an approach to recognizing hand gestures accurately during an assembly task while in collaboration with a robot co-worker. We have designed and developed a sensor system for measuring natural human-robot interactions. The position and rotation information of a human worker's hands and fingertips are tracked in 3D space while completing a task. A modified chain-code method is proposed to describe the motion trajectory of the measured hands and fingertips. The Hidden Markov Model (HMM method is adopted to recognize patterns via data streams and identify workers' gesture patterns and assembly intentions. The effectiveness of the proposed system is verified by experimental results. The outcome demonstrates that the proposed system is able to automatically segment the data streams and recognize the gesture patterns thus represented with a reasonable accuracy ratio.

Identification of motion from multi-channel EMG signals for control of prosthetic hand

International Nuclear Information System (INIS)

Geethanjali, P.; Ray, K.K.

2011-01-01

Full text: The authors in this paper propose an effective and efficient pattern recognition technique from four channel electromyogram (EMG) signals for control of multifunction prosthetic hand. Time domain features such as mean absolute value, number of zero crossings, number of slope sign changes and waveform length are considered for pattern recognition. The patterns are classified using simple logistic regression (SLR) technique and decision tree (DT) using J48 algorithm. In this study six specific hand and wrist motions are identified from the EMG signals obtained from ten different able-bodied. By considering relevant dominant features for pattern recognition, the processing time as well as memory space of the SLR and DT classifiers is found to be less in comparison with neural network (NN), k-nearest neighbour model 1 (kNN Model-1), k-nearest neighbour model 2 (kNN-Model-2) and linear discriminant analysis. The classification accuracy of SLR classifier is found to be 91 ± 1.9%. (author)

A synergy-based hand control is encoded in human motor cortical areas

Science.gov (United States)

Leo, Andrea; Handjaras, Giacomo; Bianchi, Matteo; Marino, Hamal; Gabiccini, Marco; Guidi, Andrea; Scilingo, Enzo Pasquale; Pietrini, Pietro; Bicchi, Antonio; Santello, Marco; Ricciardi, Emiliano

2016-01-01

How the human brain controls hand movements to carry out different tasks is still debated. The concept of synergy has been proposed to indicate functional modules that may simplify the control of hand postures by simultaneously recruiting sets of muscles and joints. However, whether and to what extent synergic hand postures are encoded as such at a cortical level remains unknown. Here, we combined kinematic, electromyography, and brain activity measures obtained by functional magnetic resonance imaging while subjects performed a variety of movements towards virtual objects. Hand postural information, encoded through kinematic synergies, were represented in cortical areas devoted to hand motor control and successfully discriminated individual grasping movements, significantly outperforming alternative somatotopic or muscle-based models. Importantly, hand postural synergies were predicted by neural activation patterns within primary motor cortex. These findings support a novel cortical organization for hand movement control and open potential applications for brain-computer interfaces and neuroprostheses. DOI: http://dx.doi.org/10.7554/eLife.13420.001 PMID:26880543

Kinematic design of a finger abduction mechanism for an anthropomorphic robotic hand

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L.-A. A. Demers

2011-02-01

Full Text Available This paper presents the kinematic design of an abduction mechanism for the fingers of an underactuated anthropomorphic robotic hand. This mechanism will enhance the range of feasible grasps of the underactuated hand without significantly increasing its complexity. The analysis of the link between the index finger and the third finger is first assessed, where the parameters are studied in order to follow the amplitude constraint and to minimize the coordination error. Then, the study of the mechanism joining the third finger and the little finger is summarized. Finally, a prototype of the finger's abduction system is presented.

This paper was presented at the IFToMM/ASME International Workshop on Underactuated Grasping (UG2010, 19 August 2010, Montréal, Canada.

Physical activity, sleep pattern and energy expenditure in double-handed offshore sailing.

Science.gov (United States)

Galvani, C; Ardigò, L P; Alberti, M; Daniele, F; Capelli, C

2015-12-01

The aim of the present study was to quantify total energy expenditure, activity energy expenditure and time spent at three levels of physical activity (low, moderate, high intensity) in four two-person crews during a 500-mile double-handed sailing regatta. Physical activity intensity and energy expenditure were assessed during a 500-nautical-mile double-handed offshore competition in eight male sailors (46.3±3.4 years; 180±13 cm; 85.4±12.5 kg). During the whole regatta, they wore an activity monitor that estimated energy expenditure and minutes spent at each level of intensity (sedentary, 6.0 METs). The sailors spent longer periods (Penergy expenditure was 14.26±1.89 MJ/day and the activity energy expenditure was 5.06±1.42 MJ/day. Activity energy expenditure was significantly correlated with total sleep time, boat speed, and distance covered each day (Penergy expenditure was more likely a consequence of the short and rare periods of sleep during the competition rather than of the bouts of moderate and vigorous physical activities.

Protocol to assess the neurophysiology associated with multi-segmental postural coordination

International Nuclear Information System (INIS)

Lomond, Karen V; Henry, Sharon M; Jacobs, Jesse V; Hitt, Juvena R; Horak, Fay B; Cohen, Rajal G; Schwartz, Daniel; Dumas, Julie A; Naylor, Magdalena R; Watts, Richard; DeSarno, Michael J

2013-01-01

Anticipatory postural adjustments (APAs) stabilize potential disturbances to posture caused by movement. Impaired APAs are common with disease and injury. Brain functions associated with generating APAs remain uncertain due to a lack of paired tasks that require similar limb motion from similar postural orientations, but differ in eliciting an APA while also being compatible with brain imaging techniques (e.g., functional magnetic resonance imaging; fMRI). This study developed fMRI-compatible tasks differentiated by the presence or absence of APAs during leg movement. Eighteen healthy subjects performed two leg movement tasks, supported leg raise (SLR) and unsupported leg raise (ULR), to elicit isolated limb motion (no APA) versus multi-segmental coordination patterns (including APA), respectively. Ground reaction forces under the feet and electromyographic activation amplitudes were assessed to determine the coordination strategy elicited for each task. Results demonstrated that the ULR task elicited a multi-segmental coordination that was either minimized or absent in the SLR task, indicating that it would serve as an adequate control task for fMRI protocols. A pilot study with a single subject performing each task in an MRI scanner demonstrated minimal head movement in both tasks and brain activation patterns consistent with an isolated limb movement for the SLR task versus multi-segmental postural coordination for the ULR task. (note)

ActionScript 30 Design Patterns Object Oriented Programming Techniques

CERN Document Server

Sanders, William

2008-01-01

If you're an experienced Flash or Flex developer ready to tackle sophisticated programming techniques with ActionScript 3.0, this hands-on introduction to design patterns takes you step by step through the process. You learn about various types of design patterns and construct small abstract examples before trying your hand at building full-fledged working applications outlined in the book.

Compositional symbol grounding for motor patterns.

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Greco, Alberto; Caneva, Claudio

2010-01-01

We developed a new experimental and simulative paradigm to study the establishing of compositional grounded representations for motor patterns. Participants learned to associate non-sense arm motor patterns, performed in three different hand postures, with non-sense words. There were two group conditions: in the first (compositional), each pattern was associated with a two-word (verb-adverb) sentence; in the second (holistic), each same pattern was associated with a unique word. Two experiments were performed. In the first, motor pattern recognition and naming were tested in the two conditions. Results showed that verbal compositionality had no role in recognition and that the main source of confusability in this task came from discriminating hand postures. As the naming task resulted too difficult, some changes in the learning procedure were implemented in the second experiment. In this experiment, the compositional group achieved better results in naming motor patterns especially for patterns where hand postures discrimination was relevant. In order to ascertain the differential effect, upon this result, of memory load and of systematic grounding, neural network simulations were also made. After a basic simulation that worked as a good model of subjects performance, in following simulations the number of stimuli (motor patterns and words) was increased and the systematic association between words and patterns was disrupted, while keeping the same number of words and syntax. Results showed that in both conditions the advantage for the compositional condition significantly increased. These simulations showed that the advantage for this condition may be more related to the systematicity rather than to the mere informational gain. All results are discussed in connection to the possible support of the hypothesis of a compositional motor representation and toward a more precise explanation of the factors that make compositional representations working.

Compositional symbol grounding for motor patterns

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Alberto eGreco

2010-11-01

Full Text Available We developed a new experimental and simulative paradigm to study the establishing of compositional grounded representations for motor patterns. Participants learned to associate nonsense arm motor patterns, performed in three different hand postures, with nonsense words. There were two group conditions: in the first (compositional, each pattern was associated with a two-word (verb-adverb sentence; in the second (holistic, each same pattern was associated with a unique word. Two experiments were performed. In the first, motor pattern recognition and naming were tested in the two conditions. Results showed that verbal compositionality had no role in recognition and that the main source of confusability in this task came from discriminating hand postures. As the naming task resulted too difficult, some changes in the learning procedure were implemented in the second experiment. In this experiment, the compositional group achieved better results in naming motor patterns especially for patterns where hand postures discrimination was relevant. In order to ascertain the differential effect, upon this result, of memory load and of systematic grounding, neural network simulations were also made. After a basic simulation that worked as a good model of subjects performance, in following simulations the number of stimuli (motor patterns and words was increased and the systematic association between words and patterns was disrupted, while keeping the same number of words and syntax. Results showed that in both conditions the advantage for the compositional condition significantly increased. These simulations showed that the advantage for this condition may be more related to the systematicity rather than to the mere informational gain. All results are discussed in connection to the possible support of the hypothesis of a compositional motor representation and towards a more precise explanation of the factors that make compositional representations working.

EthoHand: A dexterous robotic hand with ball-joint thumb enables complex in-hand object manipulation

OpenAIRE

Konnaris, C; Gavriel, C; Thomik, AAC; Aldo Faisal, A

2016-01-01

Our dexterous hand is a fundmanetal human feature that distinguishes us from other animals by enabling us to go beyond grasping to support sophisticated in-hand object manipulation. Our aim was the design of a dexterous anthropomorphic robotic hand that matches the human hand's 24 degrees of freedom, under-actuated by seven motors. With the ability to replicate human hand movements in a naturalistic manner including in-hand object manipulation. Therefore, we focused on the development of a no...

Hand-related physical function in rheumatic hand conditions

DEFF Research Database (Denmark)

Klokker, Louise; Terwee, Caroline B; Wæhrens, Eva Ejlersen

2016-01-01

as well as those items from the Patient Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) item bank that are relevant to patients with rheumatic hand conditions. Selection will be based on consensus among reviewers. Content validity of selected items will be established......INTRODUCTION: There is no consensus about what constitutes the most appropriate patient-reported outcome measurement (PROM) instrument for measuring physical function in patients with rheumatic hand conditions. Existing instruments lack psychometric testing and vary in feasibility...... and their psychometric qualities. We aim to develop a PROM instrument to assess hand-related physical function in rheumatic hand conditions. METHODS AND ANALYSIS: We will perform a systematic search to identify existing PROMs to rheumatic hand conditions, and select items relevant for hand-related physical function...

Hand-related physical function in rheumatic hand conditions

DEFF Research Database (Denmark)

Klokker, Louise; Terwee, Caroline; Wæhrens, Eva Elisabet Ejlersen

2016-01-01

INTRODUCTION: There is no consensus about what constitutes the most appropriate patient-reported outcome measurement (PROM) instrument for measuring physical function in patients with rheumatic hand conditions. Existing instruments lack psychometric testing and vary in feasibility...... and their psychometric qualities. We aim to develop a PROM instrument to assess hand-related physical function in rheumatic hand conditions. METHODS AND ANALYSIS: We will perform a systematic search to identify existing PROMs to rheumatic hand conditions, and select items relevant for hand-related physical function...... as well as those items from the Patient Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) item bank that are relevant to patients with rheumatic hand conditions. Selection will be based on consensus among reviewers. Content validity of selected items will be established...

Finger-to-beat coordination skill of non-dancers, street dancers, and the world champion of a street-dance competition

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Akito eMiura

2016-04-01

Full Text Available The coordination of body movements to a musical beat is a common feature of many dance styles. However, the auditory-motor coordination skills of dancers remain largely uninvestigated. The purpose of this study was to examine the auditory-motor coordination skills of non-dancers, street dancers, and the winner of a celebrated international street dance competition, while coordinating their rhythmic finger movements to a beat. The beat rate of a metronome increased from 1.0 to 3.7 Hz. The participants were asked to either flex or extend their index fingers on the beat in each condition. Under the extend-on-the-beat condition, both the dancers and non-dancers showed a spontaneous transition from the extend-on-the-beat to the flex-on-the-beat or to a phase wandering pattern. However, the critical frequency at which the transition occurred was significantly higher in the dancers (3.3 Hz than in the non-dancers (2.6 Hz. Under the flex-on-the-beat condition, the dancers were able to maintain their coordination pattern more stably at high beat rates compared to the non-dancers. Furthermore, the world champion matched the timing of movement peak velocity to the beat across the different beat rates. This may give a sense of unity between the movement and the beat for the audience because the peak velocity of the rhythmic movement works as a temporal cue for the audiovisual synchrony perception. These results suggest that the skills of accomplished dancers lie in their small finger movements and that the sensorimotor learning of street dance is characterized by a stabilization of the coordination patterns, including the inhibition of an unintentional transition to other coordination patterns.

Coordination of fictive motor activity in the larval zebrafish is generated by non-segmental mechanisms.

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Timothy D Wiggin

Full Text Available The cellular and network basis for most vertebrate locomotor central pattern generators (CPGs is incompletely characterized, but organizational models based on known CPG architectures have been proposed. Segmental models propose that each spinal segment contains a circuit that controls local coordination and sends longer projections to coordinate activity between segments. Unsegmented/continuous models propose that patterned motor output is driven by gradients of neurons and synapses that do not have segmental boundaries. We tested these ideas in the larval zebrafish, an animal that swims in discrete episodes, each of which is composed of coordinated motor bursts that progress rostrocaudally and alternate from side to side. We perturbed the spinal cord using spinal transections or strychnine application and measured the effect on fictive motor output. Spinal transections eliminated episode structure, and reduced both rostrocaudal and side-to-side coordination. Preparations with fewer intact segments were more severely affected, and preparations consisting of midbody and caudal segments were more severely affected than those consisting of rostral segments. In reduced preparations with the same number of intact spinal segments, side-to-side coordination was more severely disrupted than rostrocaudal coordination. Reducing glycine receptor signaling with strychnine reversibly disrupted both rostrocaudal and side-to-side coordination in spinalized larvae without disrupting episodic structure. Both spinal transection and strychnine decreased the stability of the motor rhythm, but this effect was not causal in reducing coordination. These results are inconsistent with a segmented model of the spinal cord and are better explained by a continuous model in which motor neuron coordination is controlled by segment-spanning microcircuits.

The Effect of Aging on Muscular Dynamics Underlying Movement Patterns Changes.

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Vernooij, Carlijn A; Rao, Guillaume; Berton, Eric; Retornaz, Frédérique; Temprado, Jean-Jacques

2016-01-01

Introduction: Aging leads to alterations not only within the complex subsystems of the neuro-musculo-skeletal system, but also in the coupling between them. Here, we studied how aging affects functional reorganizations that occur both within and between the behavioral and muscular levels, which must be coordinated to produce goal-directed movements. Using unimanual reciprocal Fitts' task, we examined the behavioral and muscular dynamics of older adults (74.4 ± 3.7 years) and compared them to those found for younger adults (23.2 ± 2.0 years). Methods: To achieve this objective, we manipulated the target size to trigger a phase transition in the behavioral regime and searched for concomitant signatures of a phase transition in the muscular coordination. Here, muscular coordination was derived by using the method of muscular synergy extraction. With this technique, we obtained functional muscular patterns through non-negative matrix factorization of the muscular signals followed by clustering the resulting synergies. Results: Older adults showed a phase transition in behavioral regime, although, in contrast to young participants, their kinematic profiles did not show a discontinuity. In parallel, muscular coordination displayed two typical signatures of a phase transition, that is, increased variability of coordination patterns and a reorganization of muscular synergies. Both signatures confirmed the existence of muscular reorganization in older adults, which is coupled with change in dynamical regime at behavioral level. However, relative to young adults, transition occurred at lower index of difficulty (ID) in older participants and the reorganization of muscular patterns lasted longer (over multiple IDs). Discussion: This implies that consistent changes occur in coordination processes across behavior and muscle. Furthermore, the repertoire of muscular patterns was reduced and somewhat modified for older adults, relative to young participants. This suggests that

Piano training in youths with hand motor impairments after damage to the developing brain

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Lampe, Renée; Thienel, Anna; Mitternacht, Jürgen; Blumenstein, Tobias; Turova, Varvara; Alves-Pinto, Ana

2015-01-01

Damage to the developing brain may lead to impairment of the hand motor function and negatively impact on patients’ quality of life. Development of manual dexterity and finger and hand motor function may be promoted by learning to play the piano. The latter brings together music with the intensive training of hand coordination and fine finger mobility. We investigated if learning to play the piano helped to improve hand motor skills in 18 youths with hand motor disorders resulting from damage during early brain development. Participants trained 35–40 minutes twice a week for 18 months with a professional piano teacher. With the use of a Musical Instrument Digital Interface piano, the uniformity of finger strokes could be objectively assessed from the timing of keystrokes. The analysis showed a significant improvement in the uniformity of keystrokes during the training. Furthermore, the youths showed strong motivation and engagement during the study. This is nevertheless an open study, and further studies remain needed to exclude effects of growth and concomitant therapies on the improvements observed and clarify which patients will more likely benefit from learning to play the piano. PMID:26345312

Are human hands and feet affected by climate? A test of Allen's rule.

Science.gov (United States)

Betti, Lia; Lycett, Stephen J; von Cramon-Taubadel, Noreen; Pearson, Osbjorn M

2015-09-01

In recent years, several studies have shown that populations from cold, high-latitude regions tend to have relatively shorter limbs than populations from tropical regions, with most of the difference due to the relative length of the zeugopods (i.e., radius, ulna, tibia, fibula). This pattern has been explained either as the consequence of long-term climatic selection or of phenotypic plasticity, with temperature having a direct effect on bone growth during development. The aims of this study were to test whether this pattern of intra-limb proportions extended to the bones of the hands and feet, and to determine whether the pattern remained significant after taking into account the effects of neutral evolutionary processes related to population history. Measurements of the limb bones, including the first metatarsal and metacarpal, were collected for 393 individuals from 10 globally distributed human populations. The relationship between intra-limb indices and minimum temperature was tested using generalized least squares regression, correcting for spatial autocorrelation. The results confirmed previous observations of a temperature-related gradient in intra-limb proportions, even accounting for population history. This pattern extends to the hands, with populations from cold regions displaying a relatively shorter and stockier first metacarpal; however, the first metatarsal appears to be wider but not shorter in cold-adapted populations. The results suggest that climatic adaptation played a role in shaping variation in limb proportions between human populations. The different patterns shown by the hands and feet might be due to the presence of evolutionary constraints on the foot to maintain efficient bipedal locomotion. © 2015 Wiley Periodicals, Inc.

Coordination of intrinsic and extrinsic hand muscle activity as a function of wrist joint angle during two-digit grasping.

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Johnston, Jamie A; Bobich, Lisa R; Santello, Marco

2010-04-26

Fingertip forces result from the activation of muscles that cross the wrist and muscles whose origins and insertions reside within the hand (extrinsic and intrinsic hand muscles, respectively). Thus, tasks that involve changes in wrist angle affect the moment arm and length, hence the force-producing capabilities, of extrinsic muscles only. If a grasping task requires the exertion of constant fingertip forces, the Central Nervous System (CNS) may respond to changes in wrist angle by modulating the neural drive to extrinsic or intrinsic muscles only or by co-activating both sets of muscles. To distinguish between these scenarios, we recorded electromyographic (EMG) activity of intrinsic and extrinsic muscles of the thumb and index finger as a function of wrist angle during a two-digit object hold task. We hypothesized that changes in wrist angle would elicit EMG amplitude modulation of the extrinsic and intrinsic hand muscles. In one experimental condition we asked subjects to exert the same digit forces at each wrist angle, whereas in a second condition subjects could choose digit forces for holding the object. EMG activity was significantly modulated in both extrinsic and intrinsic muscles as a function of wrist angle (both pextrinsic and intrinsic muscles as a muscle synergy. These findings are discussed within the theoretical frameworks of synergies and common neural input across motor nuclei of hand muscles. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Hand Fractures

Science.gov (United States)

... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is ... Hand Therapist? Media Find a Hand Surgeon Home Anatomy ... DESCRIPTION The bones of the hand serve as a framework. This framework supports the muscles that make the wrist and fingers move. When ...

Deriving Process-Driven Collaborative Editing Pattern from Collaborative Learning Flow Patterns

Science.gov (United States)

Marjanovic, Olivera; Skaf-Molli, Hala; Molli, Pascal; Godart, Claude

2007-01-01

Collaborative Learning Flow Patterns (CLFPs) have recently emerged as a new method to formulate best practices in structuring the flow of activities within various collaborative learning scenarios. The term "learning flow" is used to describe coordination and sequencing of learning tasks. This paper adopts the existing concept of CLFP and argues…

A central pattern generator producing alternative outputs: phase relations of leech heart motor neurons with respect to premotor synaptic input.

Science.gov (United States)

Norris, Brian J; Weaver, Adam L; Wenning, Angela; García, Paul S; Calabrese, Ronald L

2007-11-01

The central pattern generator (CPG) for heartbeat in leeches consists of seven identified pairs of segmental heart interneurons and one unidentified pair. Four of the identified pairs and the unidentified pair of interneurons make inhibitory synaptic connections with segmental heart motor neurons. The CPG produces a side-to-side asymmetric pattern of intersegmental coordination among ipsilateral premotor interneurons corresponding to a similarly asymmetric fictive motor pattern in heart motor neurons, and asymmetric constriction pattern of the two tubular hearts: synchronous and peristaltic. Using extracellular techniques, we recorded, in 61 isolated nerve cords, the activity of motor neurons in conjunction with the phase reference premotor heart interneuron, HN(4), and another premotor interneuron that allowed us to assess the coordination mode. These data were then coupled with a previous description of the temporal pattern of premotor interneuron activity in the two coordination modes to synthesize a global phase diagram for the known elements of the CPG and the entire motor neuron ensemble. These average data reveal the stereotypical side-to-side asymmetric patterns of intersegmental coordination among the motor neurons and show how this pattern meshes with the activity pattern of premotor interneurons. Analysis of animal-to-animal variability in this coordination indicates that the intersegmental phase progression of motor neuron activity in the midbody in the peristaltic coordination mode is the most stereotypical feature of the fictive motor pattern. Bilateral recordings from motor neurons corroborate the main features of the asymmetric motor pattern.

Joint action coordination in 2½- and 3-year old children

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Marlene eMeyer

2010-12-01

Full Text Available When acting jointly with others, adults can be as proficient as when acting individually. However how young children coordinate their actions with another person and how their action coordination develops during early childhood is not well understood. By means of a sequential button-pressing game, which could be played jointly or individually, the action coordination of 2½- and 3-year-old children was examined. Performance accuracy and variability of response timing were taken as indicators of coordination ability. Results showed substantial improvement in joint action coordination between the age of 2½- and 3, but both age groups performed equally well when acting individually. Interestingly, 3-year-olds performed equally well in the joint and the individual condition, whereas 2½-year-olds did not yet show this adult-like pattern as indicated by less accurate performance in the joint action. The findings suggest that in contrast to 3-year-olds, 2½-year-olds still have difficulties in establishing well-coordinated joint action with an adult partner. Possible underlying cognitive abilities such as action planning and action control are discussed.

Whole-brain functional magnetic resonance imaging of human brain during voluntary movements of dominant and subdominant hands

International Nuclear Information System (INIS)

Yu Wei; Yan Zixu; Ma Xiaohai; Zhang Zhaoqi; Lin Chongyu; Zang Yufeng; Weng Xuchu

2003-01-01

Objective: To identify the neural substrates of voluntary movements of dominant and subdominant hands by using the whole-brain functional magnetic resonance imaging. Methods: Seven right-handed healthy volunteers were scanned at a Sonata 1.5 Tesla magnetic resonance imaging scanner (Siemens) while they were performing the visually instructive movement tasks with their right and left index fingers. Image data were co-registered to correct head motion, spatially normalized according to the standard coordinates, and spatially smoothed with isotopic Guassian Kernel. Statistical parametric maps (activation maps) for right and left hands were generated respectively by cross-correlation analysis. Results: Voluntary movements of the right/dominant hand mainly activated contralateral primary motor cortex (MI), bilateral supplementary motor area (SMA), bilateral second motor area (MII), and ipsilateral cerebellum, whereas movements of the left/subdominant hand additionally elicited activation in contralateral premotor area (PMC). Moreover, activation volumes in SMA and MII during movements of the subdominant hand were significantly larger than those during movements of the dominant hand. Conclusion: A large set of structures in the cerebral cortex and cerebellum is involved in voluntary movements, as revealed by whole brain-based fMRI. Movements of the subdominant hand are more dependent on higher control areas, such as SMA and PMC, comparing to movements of the dominant hand

Study of recognizing multiple persons' complicated hand gestures from the video sequence acquired by a moving camera

Science.gov (United States)

Dan, Luo; Ohya, Jun

2010-02-01

Recognizing hand gestures from the video sequence acquired by a dynamic camera could be a useful interface between humans and mobile robots. We develop a state based approach to extract and recognize hand gestures from moving camera images. We improved Human-Following Local Coordinate (HFLC) System, a very simple and stable method for extracting hand motion trajectories, which is obtained from the located human face, body part and hand blob changing factor. Condensation algorithm and PCA-based algorithm was performed to recognize extracted hand trajectories. In last research, this Condensation Algorithm based method only applied for one person's hand gestures. In this paper, we propose a principal component analysis (PCA) based approach to improve the recognition accuracy. For further improvement, temporal changes in the observed hand area changing factor are utilized as new image features to be stored in the database after being analyzed by PCA. Every hand gesture trajectory in the database is classified into either one hand gesture categories, two hand gesture categories, or temporal changes in hand blob changes. We demonstrate the effectiveness of the proposed method by conducting experiments on 45 kinds of sign language based Japanese and American Sign Language gestures obtained from 5 people. Our experimental recognition results show better performance is obtained by PCA based approach than the Condensation algorithm based method.

Assessing Regional Sustainability Using a Model of Coordinated Development Index: A Case Study of Mainland China

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Qing Yang

2014-12-01

Full Text Available From a holistic view, this paper addresses a perspective of coordinated development of economy, society, and environment for regional sustainability assessment. Firstly, a comprehensive indicator system for co-evaluating the level of economic, social, and environmental subsystems is presented based on a holistic understanding of regional sustainability. Then, a coordinated development index model focusing on the level of coordination among the subsystems as well as their comprehensive development level is established. Furthermore, an empirical study of all the provinces and municipalities is conducted by collecting the panel data from 2004 to 2010. The result shows that: (1 the coordinated developments of the most developed and the most underdeveloped regions stay stable while the regions with medium development level possess more fluctuant trends during the study years; (2 regional disparities are indicated according to the grading of CDI (the coordinated development index, which are further analyzed to be related to the local economic development patterns; (3 the conditions and causes of economic, social, and environmental development in real situations under different grades of CDI are discussed through detailed case studies of typical regions, which indicate specific suggestions of sustainable development for regions in the same pattern.

From Adult Finger Tapping to Fetal Heart Beating: Retracing the Role of Coordination in Constituting Agency.

Science.gov (United States)

Solfo, Alessandro; van Leeuwen, Cees

2018-01-01

Sense of agency can be defined as the self-awareness of bodily movement, whereas extended agency as the self-awareness of affecting, through movement, events concomitant with movement. As a distinctive manifestation of agency, we review Spizzo's effect. This effect arises when agents coordinate their rhythmic movements with visual pulses. Once coordination is established, agents feel controlling the onset or the offset of the pulses through their movements. Spizzo's effect, therefore, constitutes a manifest case of extended agency, in which agents are aware of controlling, through movement, the pulses temporally concomitant with movement. We propose that sense of agency requires continuity of kinesthesia, which in turn requires the continuity of selfhood. The continuity of kinesthesia is necessarily deduced from the consistent kinematics observed in movements, whereas the continuity of selfhood may stem from the patterns of rhythmic coordination that humans encounter ever since intrauterine life. The primacy of these patterns in adults is in accordance with phenomena such as Spizzo's effect, which require coordination to be induced. We, therefore, propose coordination as the fundamental interaction from which selfhood, kinesthesia, and agency arise. Copyright © 2017 Cognitive Science Society, Inc.

Poisson Coordinates.

Science.gov (United States)

Li, Xian-Ying; Hu, Shi-Min

2013-02-01

Harmonic functions are the critical points of a Dirichlet energy functional, the linear projections of conformal maps. They play an important role in computer graphics, particularly for gradient-domain image processing and shape-preserving geometric computation. We propose Poisson coordinates, a novel transfinite interpolation scheme based on the Poisson integral formula, as a rapid way to estimate a harmonic function on a certain domain with desired boundary values. Poisson coordinates are an extension of the Mean Value coordinates (MVCs) which inherit their linear precision, smoothness, and kernel positivity. We give explicit formulas for Poisson coordinates in both continuous and 2D discrete forms. Superior to MVCs, Poisson coordinates are proved to be pseudoharmonic (i.e., they reproduce harmonic functions on n-dimensional balls). Our experimental results show that Poisson coordinates have lower Dirichlet energies than MVCs on a number of typical 2D domains (particularly convex domains). As well as presenting a formula, our approach provides useful insights for further studies on coordinates-based interpolation and fast estimation of harmonic functions.

Hand Matters: Left-Hand Gestures Enhance Metaphor Explanation

Science.gov (United States)

Argyriou, Paraskevi; Mohr, Christine; Kita, Sotaro

2017-01-01

Research suggests that speech-accompanying gestures influence cognitive processes, but it is not clear whether the gestural benefit is specific to the gesturing hand. Two experiments tested the "(right/left) hand-specificity" hypothesis for self-oriented functions of gestures: gestures with a particular hand enhance cognitive processes…

[Hand osteoarthritis].

Science.gov (United States)

Šenolt, Ladislav

Hand osteoarthritis (OA) is a common chronic disorder causing pain and limitation of mobility of affected joints. The prevalence of hand OA increases with age and more often affects females. Clinical signs obviously do not correlate with radiographic findings - symptomatic hand OA affects approximately 26 % of adult subjects, but radiographic changes can be found in up to two thirds of females and half of males older than 55 years.Disease course differ among individual patients. Hand OA is a heterogeneous disease. Nodal hand OA is the most common subtype affecting interphalangeal joints, thumb base OA affects first carpometacarpal joint. Erosive OA represents a specific subtype of hand OA, which is associated with joint inflammation, more pain, functional limitation and erosive findings on radiographs.Treatment of OA is limited. Analgesics and nonsteroidal anti-inflammatory drugs are the only agents reducing symptoms. New insights into the pathogenesis of disease should contribute to the development of novel effective treatment of hand OA.

Electrochemically fabricated polypyrrole-cobalt-oxygen coordination complex as high-performance lithium-storage materials.

Science.gov (United States)

Guo, Bingkun; Kong, Qingyu; Zhu, Ying; Mao, Ya; Wang, Zhaoxiang; Wan, Meixiang; Chen, Liquan

2011-12-23

Current lithium-ion battery (LIB) technologies are all based on inorganic electrode materials, though organic materials have been used as electrodes for years. Disadvantages such as limited thermal stability and low specific capacity hinder their applications. On the other hand, the transition metal oxides that provide high lithium-storage capacity by way of electrochemical conversion reaction suffer from poor cycling stability. Here we report a novel high-performance, organic, lithium-storage material, a polypyrrole-cobalt-oxygen (PPy-Co-O) coordination complex, with high lithium-storage capacity and excellent cycling stability. Extended X-ray absorption fine structure and Raman spectroscopy and other physical and electrochemical characterizations demonstrate that this coordination complex can be electrochemically fabricated by cycling PPy-coated Co(3)O(4) between 0.0 V and 3.0 V versus Li(+)/Li. Density functional theory (DFT) calculations indicate that each cobalt atom coordinates with two nitrogen atoms within the PPy-Co coordination layer and the layers are connected with oxygen atoms between them. Coordination weakens the C-H bonds on PPy and makes the complex a novel lithium-storage material with high capacity and high cycling stability. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Patterning a hydrogen-bonded molecular monolayer with a hand-controlled scanning probe microscope

Directory of Open Access Journals (Sweden)

Matthew F. B. Green

2014-10-01

Full Text Available One of the paramount goals in nanotechnology is molecular-scale functional design, which includes arranging molecules into complex structures at will. The first steps towards this goal were made through the invention of the scanning probe microscope (SPM, which put single-atom and single-molecule manipulation into practice for the first time. Extending the controlled manipulation to larger molecules is expected to multiply the potential of engineered nanostructures. Here we report an enhancement of the SPM technique that makes the manipulation of large molecular adsorbates much more effective. By using a commercial motion tracking system, we couple the movements of an operator's hand to the sub-angstrom precise positioning of an SPM tip. Literally moving the tip by hand we write a nanoscale structure in a monolayer of large molecules, thereby showing that our method allows for the successful execution of complex manipulation protocols even when the potential energy surface that governs the interaction behaviour of the manipulated nanoscale object(s is largely unknown.

Developing professional habits of hand hygiene in intensive care settings: An action-research intervention.

Science.gov (United States)

Battistella, Giuseppe; Berto, Giuliana; Bazzo, Stefania

2017-02-01

To explore perceptions and unconscious psychological processes underlying handwashing behaviours of intensive care nurses, to implement organisational innovations for improving hand hygiene in clinical practice. An action-research intervention was performed in 2012 and 2013 in the intensive care unit of a public hospital in Italy, consisting of: structured interviews, semantic analysis, development and validation of a questionnaire, team discussion, project design and implementation. Five general workers, 16 staff nurses and 53 nurse students participated in the various stages. Social handwashing emerged as a structured and efficient habit, which follows automatically the pattern "cue/behaviour/gratification" when hands are perceived as "dirty". The perception of "dirt" starts unconsciously the process of social washing also in professional settings. Professional handwashing is perceived as goal-directed. The main concern identified is the fact that washing hands requires too much time to be performed in a setting of urgency. These findings addressed participants to develop a professional "habit-directed" hand hygiene procedure, to be implemented at beginning of workshifts. Handwashing is a ritualistic behaviour driven by deep and unconscious patterns, and social habits affect professional practice. Creating professional habits of hand hygiene could be a key solution to improve compliance in intensive care settings. Copyright © 2016. Published by Elsevier Ltd.

Virtual Hand Feedback Reduces Reaction Time in an Interactive Finger Reaching Task.

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Johannes Brand

Full Text Available Computer interaction via visually guided hand or finger movements is a ubiquitous part of daily computer usage in work or gaming. Surprisingly, however, little is known about the performance effects of using virtual limb representations versus simpler cursors. In this study 26 healthy right-handed adults performed cued index finger flexion-extension movements towards an on-screen target while wearing a data glove. They received each of four different types of real-time visual feedback: a simple circular cursor, a point light pattern indicating finger joint positions, a cartoon hand and a fully shaded virtual hand. We found that participants initiated the movements faster when receiving feedback in the form of a hand than when receiving circular cursor or point light feedback. This overall difference was robust for three out of four hand versus circle pairwise comparisons. The faster movement initiation for hand feedback was accompanied by a larger movement amplitude and a larger movement error. We suggest that the observed effect may be related to priming of hand information during action perception and execution affecting motor planning and execution. The results may have applications in the use of body representations in virtual reality applications.

Kinematic rate control of simulated robot hand at or near wrist singularity

Science.gov (United States)

Barker, K.; Houck, J. A.; Carzoo, S. W.

1985-01-01

A robot hand should obey movement commands from an operator on a computer program as closely as possible. However, when two of the three rotational axes of the robot wrist are colinear, the wrist loses a degree of freedom, and the usual resolved rate equations (used to move the hand in response to an operator's inputs) are indeterminant. Furthermore, rate limiting occurs in close vicinity to this singularity. An analysis shows that rate limiting occurs not only in the vicinity of this singularity but also substantially away from it, even when the operator commands rotational rates of the robot hand that are only a small percentage of the operational joint rate limits. Therefore, joint angle rates are scaled when they exceed operational limits in a real time simulation of a robot arm. Simulation results show that a small dead band avoids the wrist singularity in the resolved rate equations but can introduce a high frequency oscillation close to the singularity. However, when a coordinated wrist movement is used in conjunction with the resolved rate equations, the high frequency oscillation disappears.

Dynamic Skin Patterns in Cephalopods

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Martin J. How

2017-06-01

Full Text Available Cephalopods are unrivaled in the natural world in their ability to alter their visual appearance. These mollusks have evolved a complex system of dermal units under neural, hormonal, and muscular control to produce an astonishing variety of body patterns. With parallels to the pixels on a television screen, cephalopod chromatophores can be coordinated to produce dramatic, dynamic, and rhythmic displays, defined collectively here as “dynamic patterns.” This study examines the nature, context, and potential functions of dynamic patterns across diverse cephalopod taxa. Examples are presented for 21 species, including 11 previously unreported in the scientific literature. These range from simple flashing or flickering patterns, to highly complex passing wave patterns involving multiple skin fields.

Dynamic Skin Patterns in Cephalopods

Science.gov (United States)

How, Martin J.; Norman, Mark D.; Finn, Julian; Chung, Wen-Sung; Marshall, N. Justin

2017-01-01

Cephalopods are unrivaled in the natural world in their ability to alter their visual appearance. These mollusks have evolved a complex system of dermal units under neural, hormonal, and muscular control to produce an astonishing variety of body patterns. With parallels to the pixels on a television screen, cephalopod chromatophores can be coordinated to produce dramatic, dynamic, and rhythmic displays, defined collectively here as “dynamic patterns.” This study examines the nature, context, and potential functions of dynamic patterns across diverse cephalopod taxa. Examples are presented for 21 species, including 11 previously unreported in the scientific literature. These range from simple flashing or flickering patterns, to highly complex passing wave patterns involving multiple skin fields. PMID:28674500

Development and pilot testing of HEXORR: Hand EXOskeleton Rehabilitation Robot

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Godfrey Sasha B

2010-07-01

Full Text Available Abstract Background Following acute therapeutic interventions, the majority of stroke survivors are left with a poorly functioning hemiparetic hand. Rehabilitation robotics has shown promise in providing patients with intensive therapy leading to functional gains. Because of the hand's crucial role in performing activities of daily living, attention to hand therapy has recently increased. Methods This paper introduces a newly developed Hand Exoskeleton Rehabilitation Robot (HEXORR. This device has been designed to provide full range of motion (ROM for all of the hand's digits. The thumb actuator allows for variable thumb plane of motion to incorporate different degrees of extension/flexion and abduction/adduction. Compensation algorithms have been developed to improve the exoskeleton's backdrivability by counteracting gravity, stiction and kinetic friction. We have also designed a force assistance mode that provides extension assistance based on each individual's needs. A pilot study was conducted on 9 unimpaired and 5 chronic stroke subjects to investigate the device's ability to allow physiologically accurate hand movements throughout the full ROM. The study also tested the efficacy of the force assistance mode with the goal of increasing stroke subjects' active ROM while still requiring active extension torque on the part of the subject. Results For 12 of the hand digits'15 joints in neurologically normal subjects, there were no significant ROM differences (P > 0.05 between active movements performed inside and outside of HEXORR. Interjoint coordination was examined in the 1st and 3rd digits, and no differences were found between inside and outside of the device (P > 0.05. Stroke subjects were capable of performing free hand movements inside of the exoskeleton and the force assistance mode was successful in increasing active ROM by 43 ± 5% (P Conclusions Our pilot study shows that this device is capable of moving the hand's digits through

Development and pilot testing of HEXORR: Hand EXOskeleton Rehabilitation Robot

Science.gov (United States)

2010-01-01

Background Following acute therapeutic interventions, the majority of stroke survivors are left with a poorly functioning hemiparetic hand. Rehabilitation robotics has shown promise in providing patients with intensive therapy leading to functional gains. Because of the hand's crucial role in performing activities of daily living, attention to hand therapy has recently increased. Methods This paper introduces a newly developed Hand Exoskeleton Rehabilitation Robot (HEXORR). This device has been designed to provide full range of motion (ROM) for all of the hand's digits. The thumb actuator allows for variable thumb plane of motion to incorporate different degrees of extension/flexion and abduction/adduction. Compensation algorithms have been developed to improve the exoskeleton's backdrivability by counteracting gravity, stiction and kinetic friction. We have also designed a force assistance mode that provides extension assistance based on each individual's needs. A pilot study was conducted on 9 unimpaired and 5 chronic stroke subjects to investigate the device's ability to allow physiologically accurate hand movements throughout the full ROM. The study also tested the efficacy of the force assistance mode with the goal of increasing stroke subjects' active ROM while still requiring active extension torque on the part of the subject. Results For 12 of the hand digits'15 joints in neurologically normal subjects, there were no significant ROM differences (P > 0.05) between active movements performed inside and outside of HEXORR. Interjoint coordination was examined in the 1st and 3rd digits, and no differences were found between inside and outside of the device (P > 0.05). Stroke subjects were capable of performing free hand movements inside of the exoskeleton and the force assistance mode was successful in increasing active ROM by 43 ± 5% (P < 0.001) and 24 ± 6% (P = 0.041) for the fingers and thumb, respectively. Conclusions Our pilot study shows that this device

Sensitive Ceramics_Pattern #1-#5

DEFF Research Database (Denmark)

2014-01-01

pattern of which are reflecting the position and speed of the hands. In that way the user is able to interact and model a responding pattern. The second level has to do with realizing the modules in ceramics by 3d printing directly in porcelain with a RapMan printer that coils up the 3d shape in layers...

Frequency characteristics of coordinate sequences of linear recurrences over Galois rings

Science.gov (United States)

Kamlovskii, O. V.

2013-12-01

We consider some properties of the coordinate sequences of linear recurrences over Galois rings which characterize the possibility of regarding them as pseudo-random sequences. We study the periodicity properties, linear complexity and frequency characteristics of these sequences. Up to now, these parameters have been studied mainly in the case when the linear recurring sequence has maximal possible period. We investigate the coordinate sequences of linear recurrences of not necessarily maximal period. We obtain sharpened and generalized estimates for the number of elements and r-patterns on the cycles and intervals of these sequences.

Frequency characteristics of coordinate sequences of linear recurrences over Galois rings

International Nuclear Information System (INIS)

Certification Research Center, Moscow (Russian Federation))" data-affiliation=" (LLC Certification Research Center, Moscow (Russian Federation))" >Kamlovskii, O V

2013-01-01

We consider some properties of the coordinate sequences of linear recurrences over Galois rings which characterize the possibility of regarding them as pseudo-random sequences. We study the periodicity properties, linear complexity and frequency characteristics of these sequences. Up to now, these parameters have been studied mainly in the case when the linear recurring sequence has maximal possible period. We investigate the coordinate sequences of linear recurrences of not necessarily maximal period. We obtain sharpened and generalized estimates for the number of elements and r-patterns on the cycles and intervals of these sequences

Denmark: HAND in HAND Policy Questionnaire

DEFF Research Database (Denmark)

Laursen, Hilmar Dyrborg; Nielsen, Birgitte Lund

2018-01-01

Som del af det internationale EU finansierede projekt Hand in Hand, der fokuserer på de såkaldte SEI-kompetencer (Social, Emotional, Intercultural), er dansk policy i relation til elevernes sociale, emotionelle og interkulturelle læring kortlagt i denne rapport. Der refereres bl.a. til "elevernes...

Don't rock the boat: how antiphase crew coordination affects rowing.

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Anouk J de Brouwer

Full Text Available It is generally accepted that crew rowing requires perfect synchronization between the movements of the rowers. However, a long-standing and somewhat counterintuitive idea is that out-of-phase crew rowing might have benefits over in-phase (i.e., synchronous rowing. In synchronous rowing, 5 to 6% of the power produced by the rower(s is lost to velocity fluctuations of the shell within each rowing cycle. Theoretically, a possible way for crews to increase average boat velocity is to reduce these fluctuations by rowing in antiphase coordination, a strategy in which rowers perfectly alternate their movements. On the other hand, the framework of coordination dynamics explicates that antiphase coordination is less stable than in-phase coordination, which may impede performance gains. Therefore, we compared antiphase to in-phase crew rowing performance in an ergometer experiment. Nine pairs of rowers performed a two-minute maximum effort in-phase and antiphase trial at 36 strokes min(-1 on two coupled free-floating ergometers that allowed for power losses to velocity fluctuations. Rower and ergometer kinetics and kinematics were measured during the trials. All nine pairs easily acquired antiphase rowing during the warm-up, while one pair's coordination briefly switched to in-phase during the maximum effort trial. Although antiphase interpersonal coordination was indeed less accurate and more variable, power production was not negatively affected. Importantly, in antiphase rowing the decreased power loss to velocity fluctuations resulted in more useful power being transferred to the ergometer flywheels. These results imply that antiphase rowing may indeed improve performance, even without any experience with antiphase technique. Furthermore, it demonstrates that although perfectly synchronous coordination may be the most stable, it is not necessarily equated with the most efficient or optimal performance.

Eye tracking a self-moved target with complex hand-target dynamics

Science.gov (United States)

Landelle, Caroline; Montagnini, Anna; Madelain, Laurent

2016-01-01

Previous work has shown that the ability to track with the eye a moving target is substantially improved when the target is self-moved by the subject's hand compared with when being externally moved. Here, we explored a situation in which the mapping between hand movement and target motion was perturbed by simulating an elastic relationship between the hand and target. Our objective was to determine whether the predictive mechanisms driving eye-hand coordination could be updated to accommodate this complex hand-target dynamics. To fully appreciate the behavioral effects of this perturbation, we compared eye tracking performance when self-moving a target with a rigid mapping (simple) and a spring mapping as well as when the subject tracked target trajectories that he/she had previously generated when using the rigid or spring mapping. Concerning the rigid mapping, our results confirmed that smooth pursuit was more accurate when the target was self-moved than externally moved. In contrast, with the spring mapping, eye tracking had initially similar low spatial accuracy (though shorter temporal lag) in the self versus externally moved conditions. However, within ∼5 min of practice, smooth pursuit improved in the self-moved spring condition, up to a level similar to the self-moved rigid condition. Subsequently, when the mapping unexpectedly switched from spring to rigid, the eye initially followed the expected target trajectory and not the real one, thereby suggesting that subjects used an internal representation of the new hand-target dynamics. Overall, these results emphasize the stunning adaptability of smooth pursuit when self-maneuvering objects with complex dynamics. PMID:27466129

Non-uniformly sampled grids in double pole coordinate system for freeform reflector construction

Science.gov (United States)

Ma, Donglin; Pacheco, Shaun; Feng, Zexin; Liang, Rongguang

2015-08-01

We propose a new method to design freeform reflectors by nonuniformly sampling the source intensity distribution in double pole coordinate system. In double pole coordinate system, there is no pole for the whole hemisphere because both poles of the spherical coordinate system are moved to southernmost point of the sphere and overlapped together. With symmetric definition of both angular coordinates in the modified double pole coordinate system, a better match between the source intensity distribution and target irradiance distribution can be achieved for reflectors with large acceptance solid angle, leading to higher light efficiency and better uniformity on the target surface. With non-uniform sampling of the source intensity, we can design circular freeform reflector to obtain uniform rectangular illumination pattern. Aided by the feedback optimization, the freeform reflector can achieve the collection efficiency for ideal point source over 0.7 and relative standard deviation (RSD) less than 0.1.

Sinusoidal error perturbation reveals multiple coordinate systems for sensorymotor adaptation.

Science.gov (United States)

Hudson, Todd E; Landy, Michael S

2016-02-01

A coordinate system is composed of an encoding, defining the dimensions of the space, and an origin. We examine the coordinate encoding used to update motor plans during sensory-motor adaptation to center-out reaches. Adaptation is induced using a novel paradigm in which feedback of reach endpoints is perturbed following a sinewave pattern over trials; the perturbed dimensions of the feedback were the axes of a Cartesian coordinate system in one session and a polar coordinate system in another session. For center-out reaches to randomly chosen target locations, reach errors observed at one target will require different corrections at other targets within Cartesian- and polar-coded systems. The sinewave adaptation technique allowed us to simultaneously adapt both dimensions of each coordinate system (x-y, or reach gain and angle), and identify the contributions of each perturbed dimension by adapting each at a distinct temporal frequency. The efficiency of this technique further allowed us to employ perturbations that were a fraction the size normally used, which avoids confounding automatic adaptive processes with deliberate adjustments made in response to obvious experimental manipulations. Subjects independently corrected errors in each coordinate in both sessions, suggesting that the nervous system encodes both a Cartesian- and polar-coordinate-based internal representation for motor adaptation. The gains and phase lags of the adaptive responses are not readily explained by current theories of sensory-motor adaptation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Muscle activation patterns in acceleration-based phases during reach-to-grasp movement.

Science.gov (United States)

Tokuda, Keisuke; Lee, Bumsuk; Shiihara, Yasufumi; Takahashi, Kazuhiro; Wada, Naoki; Shirakura, Kenji; Watanabe, Hideomi

2016-11-01

[Purpose] An earlier study divided reaching activity into characteristic phases based on hand velocity profiles. By synchronizing muscle activities and the acceleration profile, a phasing approach for reaching movement, based on hand acceleration profiles, was attempted in order to elucidate the roles of individual muscle activities in the different phases of the acceleration profile in reaching movements. [Subjects and Methods] Ten healthy volunteer subjects participated in this study. The aim was to electromyographically evaluate muscles around the shoulder, the upper trapezius, the anterior deltoid, the biceps brachii, and the triceps brachii, most of which have been used to evaluate arm motion, as well as the acceleration of the upper limb during simple reaching movement in the reach-to-grasp task. [Results] Analysis showed the kinematic trajectories of the acceleration during a simple biphasic profile of the reaching movement could be divided into four phases: increasing acceleration (IA), decreasing acceleration (DA), increasing deceleration (ID), and decreasing deceleration (DD). Muscles around the shoulder showed different activity patterns, which were closely associated with these acceleration phases. [Conclusion] These results suggest the important role of the four phases, derived from the acceleration trajectory, in the elucidation of the muscular mechanisms which regulate and coordinate the muscles around the shoulder in reaching movements.

Representing tools as hand movements: early and somatotopic visuomotor transformations.

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Bartoli, Eleonora; Maffongelli, Laura; Jacono, Marco; D'Ausilio, Alessandro

2014-08-01

The term affordance defines a property of objects, which relates to the possible interactions that an agent can carry out on that object. In monkeys, canonical neurons encode both the visual and the motor properties of objects with high specificity. However, it is not clear if in humans exists a similarly fine-grained description of these visuomotor transformations. In particular, it has not yet been proven that the processing of visual features related to specific affordances induces both specific and early visuomotor transformations, given that complete specificity has been reported to emerge quite late (300-450ms). In this study, we applied an adaptation-stimulation paradigm to investigate early cortico-spinal facilitation and hand movements׳ synergies evoked by the observation of tools. We adapted, through passive observation of finger movements, neuronal populations coding either for precision or power grip actions. We then presented the picture of one tool affording one of the two grasps types and applied single-pulse Transcranial Magnetic Stimulation (TMS) to the hand primary motor cortex, 150ms after image onset. Cortico-spinal excitability of the Abductor Digiti Minimi and Abductor Pollicis Brevis showed a detailed pattern of modulations, matching tools׳ affordances. Similarly, TMS-induced hand movements showed a pattern of grip-specific whole hand synergies. These results offer a direct proof of the emergence of an early visuomotor transformation when tools are observed, that maintains the same amount of synergistic motor details as the actions we can perform on them. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Hand Surgery: Anesthesia

Science.gov (United States)

... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Hand Surgery Anesthesia Email to a friend * required ...

The Event Coordination Notation: Execution Engine and Programming Framework

DEFF Research Database (Denmark)

Kindler, Ekkart

2012-01-01

that was written manually. In this paper, we rephrase the main concepts of ECNO. The focus of this paper, however, is on the architecture of the ECNO execution engine and its programming framework. We will show how this framework allows us to integrate ECNO with object-oriented models, how it works without any......ECNO (Event Coordination Notation) is a notation for modelling the behaviour of a software system on top of some object-oriented data model. ECNO has two main objectives: On the one hand, ECNO should allow modelling the behaviour of a system on the domain level; on the other hand, it should...... be possible to completely generate code from ECNO and the underlying object-oriented domain models. Today, there are several approaches that would allow to do this. But, most of them would require that the data models and the behaviour models are using the same technology and the code is generated together...

New potential for the Leitz Infinity Coordinate Measuring Machine

CERN Document Server

Sanz, Claude; MAINAUD DURAND , Hélène; Schneider, Jurgen; Steffens, Norbert; Morantz , Paul; Shore , Paul

2015-01-01

The following study is realised within the frame of the PACMAN project: a study on Particle Accelerator Components Metrology and Alignment to the Nanometre scale, which is a Marie Curie program supported by the European commission and hosted by CERN (European Organisation for Nuclear Research). The aim of this program is to develop and build a pre-alignment bench on which each component is aligned to the required level in one single step using a stretched wire. During the operation, the centre of the stretched wire is aligned with the magnetic axis of the magnet. Then, the position of the wire is measured to the highest possible accuracy using a 3D Coordinate Measuring Machine (CMM) Leitz PMM-C Infinity from HEXAGON Metrology. The research described in this paper is two-fold: on one hand we apply a strong magnetic field to the head of the CMM and evaluate its influence on the measurement accuracy; on the other hand we measure the position

Factors influencing hand/eye synchronicity in the computer age.

Science.gov (United States)

Grant, A H

1992-09-01

In using a computer, the relation of vision to hand/finger actuated keyboard usage in performing fine motor-coordinated functions is influenced by the physical location, size, and collective placement of the keys. Traditional nonprehensile flat/rectangular keyboard applications usually require a high and nearly constant level of visual attention. Biometrically shaped keyboards would allow for prehensile hand-posturing, thus affording better tactile familiarity with the keys, requiring less intense and less constant level of visual attention to the task, and providing a greater measure of freedom from having to visualize the key(s). Workpace and related physiological changes, aging, onset of monocularization (intermittent lapsing of binocularity for near vision) that accompanies presbyopia, tool colors, and background contrast are factors affecting constancy of visual attention to task performance. Capitas extension, excessive excyclotorsion, and repetitive strain injuries (such as carpal tunnel syndrome) are common and debilitating concomitants to computer usage. These problems can be remedied by improved keyboard design. The salutary role of mnemonics in minimizing visual dependency is discussed.

Hand Anatomy

Science.gov (United States)

... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is ... Hand Therapist? Media Find a Hand Surgeon Home Anatomy Bones Joints Muscles Nerves Vessels Tendons Anatomy The upper extremity is ...

Control of a Supernumerary Robotic Hand by Foot: An Experimental Study in Virtual Reality.

Science.gov (United States)

Abdi, Elahe; Burdet, Etienne; Bouri, Mohamed; Bleuler, Hannes

2015-01-01

In the operational theater, the surgical team could highly benefit from a robotic supplementary hand under the surgeon's full control. The surgeon may so become more autonomous; this may reduce communication errors with the assistants and take over difficult tasks such as holding tools without tremor. In this paper, we therefore examine the possibility to control a third robotic hand with one foot's movements. Three experiments in virtual reality were designed to assess the feasibility of this control strategy, the learning curve of the subjects in different tasks and the coordination of foot movements with the two natural hands. Results show that the limbs are moved simultaneously, in parallel rather than serially. Participants' performance improved within a few minutes of practice without any specific difficulty to complete the tasks. Subjective assessment by the subjects indicated that controlling a third hand by foot has been easy and required only negligible physical and mental efforts. The sense of ownership was reported to improve through the experiments. The mental burden was not directly related to the level of motion required by a task, but depended on the type of activity and practice. The most difficult task was moving two hands and foot in opposite directions. These results suggest that a combination of practice and appropriate tasks can enhance the learning process for controlling a robotic hand by foot.

Control of a Supernumerary Robotic Hand by Foot: An Experimental Study in Virtual Reality.

Directory of Open Access Journals (Sweden)

Elahe Abdi

Full Text Available In the operational theater, the surgical team could highly benefit from a robotic supplementary hand under the surgeon's full control. The surgeon may so become more autonomous; this may reduce communication errors with the assistants and take over difficult tasks such as holding tools without tremor. In this paper, we therefore examine the possibility to control a third robotic hand with one foot's movements. Three experiments in virtual reality were designed to assess the feasibility of this control strategy, the learning curve of the subjects in different tasks and the coordination of foot movements with the two natural hands. Results show that the limbs are moved simultaneously, in parallel rather than serially. Participants' performance improved within a few minutes of practice without any specific difficulty to complete the tasks. Subjective assessment by the subjects indicated that controlling a third hand by foot has been easy and required only negligible physical and mental efforts. The sense of ownership was reported to improve through the experiments. The mental burden was not directly related to the level of motion required by a task, but depended on the type of activity and practice. The most difficult task was moving two hands and foot in opposite directions. These results suggest that a combination of practice and appropriate tasks can enhance the learning process for controlling a robotic hand by foot.

Functional magnetic resonance imaging exploration of combined hand and speech movements in Parkinson's disease.

Science.gov (United States)

Pinto, Serge; Mancini, Laura; Jahanshahi, Marjan; Thornton, John S; Tripoliti, Elina; Yousry, Tarek A; Limousin, Patricia

2011-10-01

Among the repertoire of motor functions, although hand movement and speech production tasks have been investigated widely by functional neuroimaging, paradigms combining both movements have been studied less so. Such paradigms are of particular interest in Parkinson's disease, in which patients have specific difficulties performing two movements simultaneously. In 9 unmedicated patients with Parkinson's disease and 15 healthy control subjects, externally cued tasks (i.e., hand movement, speech production, and combined hand movement and speech production) were performed twice in a random order and functional magnetic resonance imaging detected cerebral activations, compared to the rest. F-statistics tested within-group (significant activations at P values 10 voxels). For control subjects, the combined task activations comprised the sum of those obtained during hand movement and speech production performed separately, reflecting the neural correlates of performing movements sharing similar programming modalities. In patients with Parkinson's disease, only activations underlying hand movement were observed during the combined task. We interpreted this phenomenon as patients' potential inability to recruit facilitatory activations while performing two movements simultaneously. This lost capacity could be related to a functional prioritization of one movement (i.e., hand movement), in comparison with the other (i.e., speech production). Our observation could also reflect the inability of patients with Parkinson's disease to intrinsically engage the motor coordination necessary to perform a combined task. Copyright © 2011 Movement Disorder Society.

The impact of shoulder abduction loading on EMG-based intention detection of hand opening and closing after stroke.

Science.gov (United States)

Lan, Yiyun; Yao, Jun; Dewald, Julius P A

2011-01-01

Many stroke patients are subject to limited hand functions in the paretic arm due to a significant loss of Corticospinal Tract (CST) fibers. A possible solution for this problem is to classify surface Electromyography (EMG) signals generated by hand movements and uses that to implement Functional Electrical Stimulation (FES). However, EMG usually presents an abnormal muscle coactivation pattern shown as increased coupling between muscles within and/or across joints after stroke. The resulting Abnormal Muscle Synergies (AMS) could make the classification more difficult in individuals with stroke, especially when attempting to use the hand together with other joints in the paretic arm. Therefore, this study is aimed at identifying the impact of AMS following stroke on EMG pattern recognition between two hand movements. In an effort to achieve this goal, 7 chronic hemiparetic chronic stroke subjects were recruited and asked to perform hand opening and closing movements at their paretic arm while being either fully supported by a virtual table or loaded with 25% of subject's maximum shoulder abduction force. During the execution of motor tasks EMG signals from the wrist flexors and extensors were simultaneously acquired. Our results showed that increased synergy-induced activity at elbow flexors, induced by increasing shoulder abduction loading, deteriorated the performance of EMG pattern recognition for hand opening for those with a weak grasp strength and EMG activity. However, no such impact on hand closing has yet been observed possibly because finger/wrist flexion is facilitated by the shoulder abduction-induced flexion synergy.

Return to Work for Nurses With Hand Dermatitis.

Science.gov (United States)

Chen, Jennifer; Gomez, Pilar; Kudla, Irena; DeKoven, Joel; Holness, D Linn; Skotnicki, Sandra

2016-01-01

Occupational skin disease is common in healthcare workers. If the healthcare worker develops moderate to severe dermatitis, return to work (RTW) may be challenging. The study objectives were to review the impact of an RTW program on the work status of nurses with occupational hand dermatitis and to identify successful intervention methods and strategies. Nurses who received RTW services at a tertiary occupational medicine clinic were identified, and information related to their diagnosis and RTW was abstracted from their charts. Eighteen nurses with irritant hand dermatitis who received RTW services were identified. Twelve nurses (67%) were performing administrative duties because of their skin condition when admitted to the RTW program, and others were performing patient care with modifications. A graduated RTW trial was commonly implemented with optimized skin care management and monitoring by physicians and the RTW coordinator. Upon discharge, 14 nurses (78%) had returned to their nursing roles with direct patient care, 3 (17%) were working as nurses in non-patient care roles, and 1 (6%) was on permanent disability. A graduated RTW trial to reduce cumulative irritant exposure is a crucial strategy to facilitate nurses' transition back to work and to maintain direct patient care nursing roles.

Planned development and coordination of public policies as a starting point in the harmonization of national regulations with the EU aquis

Directory of Open Access Journals (Sweden)

Jovanić Tatjana

2014-01-01

Full Text Available One of the most important aspects of harmonizing Serbian legislation with the EU law, however still neglected in Serbia, is the mutual relationship between the design and coordination of public policies on the one hand, and the harmonization of legislation in the course of negotiations for EU accession, on the other hand. This aspect has been largely neglected because of the misuse of emergency procedure for adopting legislation in order to assure compatibility with the EU law, but also due to underdeveloped regulatory policies, which has been reduced to the guillotine of legislation, instead of developing a cycle of policy and analytical phase that precedes the drafting of legislation. Although the negotiating structure of European integration has been improved, the Negotiation Team and Coordination Body certainly can not replace the role of policy makers in their creation. Since the new Law on Ministries envisaged the creation of the Secretariat for the coordination of public policies, an institutional prerequisite for the implementation of the function of harmonizing public policy proposals has been put forward, but is not yet clear what powers in the policy cycle this institution would have. In any case, this administrative body will certainly complement Serbian coordination structure in the negotiation process.

Intra- and Interpersonal Movement Coordination in Jointly Moving a Rocking Board

NARCIS (Netherlands)

Bosga, J.; Meulenbroek, R.G.J.; Cuijpers, R.H.

2010-01-01

In this study, we investigate how two persons (dyads) coordinate their movements when performing cyclical motion patterns on a rocking board. In keeping with the Leading Joint Hypothesis (Dounskaia, 2005), the movement dynamics of the collaborating participants were expected to display features of a

Mathematical and numerical analysis of systems of compressible hydrodynamics and photonics with polar coordinates

International Nuclear Information System (INIS)

Meltz, Bertrand

2015-01-01

This thesis deals with the mathematical and numerical analysis of the systems of compressible hydrodynamics and radiative transfer. More precisely, we study the derivation of numerical methods with 2D polar coordinates (one for the radius, one for the angle) where equations are discretized on regular polar grids. On one hand, these methods are well-suited for the simulation of flows with polar symmetries since they preserve these symmetries by construction. On the other hand, such coordinates systems introduce geometrical singularities as well as geometrical source terms which must be carefully treated. The first part of this document is devoted to the study of hydrodynamics equations, or Euler equations. We propose a new class of arbitrary high-order numerical schemes in both space and time and rely on directional splitting methods for the resolution of 2D equations. Each sub-system is solved using a Lagrange+Remap solver. We study the influence of the r=0 geometrical singularities of the cylindrical and spherical coordinates systems on the precision of the 2D numerical solutions. The second part of this document is devoted to the study of radiative transfer equations. In these equations, the unknowns depend on a large number of variables and a stiff source term is involved. The main difficulty consists in capturing the correct asymptotic behavior on coarse grids. We first construct a class of models where the radiative intensity is projected on a truncated spherical harmonics basis in order to lower the number of mathematical dimensions. Then we propose an Asymptotic Preserving scheme built in polar coordinates and we show that the scheme capture the correct diffusion limit in the radial direction as well as in the polar direction. (author) [fr

Organizing to Coordinate Child Care Services. (With an Appendix) The Greater Minneapolis Day Care Association: Early History.

Science.gov (United States)

Ratliff, Patricia; Berryman, Pauline

Systems of coordinating child care services are analyzed as a guide to organizing. Federal Community Child Care (4-C) are the focus of the analysis. In Part I, evolution of coordination, an initial steering committee is followed through its various phases of expansion--initial impetus, visibility, staffing patterns, parent involvement, community…

Two-phase strategy of controlling motor coordination determined by task performance optimality.

Science.gov (United States)

Shimansky, Yury P; Rand, Miya K

2013-02-01

A quantitative model of optimal coordination between hand transport and grip aperture has been derived in our previous studies of reach-to-grasp movements without utilizing explicit knowledge of the optimality criterion or motor plant dynamics. The model's utility for experimental data analysis has been demonstrated. Here we show how to generalize this model for a broad class of reaching-type, goal-directed movements. The model allows for measuring the variability of motor coordination and studying its dependence on movement phase. The experimentally found characteristics of that dependence imply that execution noise is low and does not affect motor coordination significantly. From those characteristics it is inferred that the cost of neural computations required for information acquisition and processing is included in the criterion of task performance optimality as a function of precision demand for state estimation and decision making. The precision demand is an additional optimized control variable that regulates the amount of neurocomputational resources activated dynamically. It is shown that an optimal control strategy in this case comprises two different phases. During the initial phase, the cost of neural computations is significantly reduced at the expense of reducing the demand for their precision, which results in speed-accuracy tradeoff violation and significant inter-trial variability of motor coordination. During the final phase, neural computations and thus motor coordination are considerably more precise to reduce the cost of errors in making a contact with the target object. The generality of the optimal coordination model and the two-phase control strategy is illustrated on several diverse examples.

Segmentation of turbo generator and reactor coolant pump vibratory patterns: a syntactic pattern recognition approach

International Nuclear Information System (INIS)

Tira, Z.

1993-02-01

This study was undertaken in the context of turbogenerator and reactor coolant pump vibration surveillance. Vibration meters are used to monitor equipment condition. An anomaly will modify the signal mean. At the present time, the expert system DIVA, developed to automate diagnosis, requests the operator to identify the nature of the pattern change thus indicated. In order to minimize operator intervention, we have to automate on the one hand classification and on the other hand, detection and segmentation of the patterns. The purpose of this study is to develop a new automatic system for the segmentation and classification of signals. The segmentation is based on syntactic pattern recognition. For the classification, a decision tree is used. The signals to process are the rms values of the vibrations measured on rotating machines. These signals are randomly sampled. All processing is automatic and no a priori statistical knowledge on the signals is required. The segmentation performances are assessed by tests on vibratory signals. (author). 31 figs

Ordered patterns of cell shape and orientational correlation during spontaneous cell migration.

Directory of Open Access Journals (Sweden)

Yusuke T Maeda

Full Text Available BACKGROUND: In the absence of stimuli, most motile eukaryotic cells move by spontaneously coordinating cell deformation with cell movement in the absence of stimuli. Yet little is known about how cells change their own shape and how cells coordinate the deformation and movement. Here, we investigated the mechanism of spontaneous cell migration by using computational analyses. METHODOLOGY: We observed spontaneously migrating Dictyostelium cells in both a vegetative state (round cell shape and slow motion and starved one (elongated cell shape and fast motion. We then extracted regular patterns of morphological dynamics and the pattern-dependent systematic coordination with filamentous actin (F-actin and cell movement by statistical dynamic analyses. CONCLUSIONS/SIGNIFICANCE: We found that Dictyostelium cells in both vegetative and starved states commonly organize their own shape into three ordered patterns, elongation, rotation, and oscillation, in the absence of external stimuli. Further, cells inactivated for PI3-kinase (PI3K and/or PTEN did not show ordered patterns due to the lack of spatial control in pseudopodial formation in both the vegetative and starved states. We also found that spontaneous polarization was achieved in starved cells by asymmetric localization of PTEN and F-actin. This breaking of the symmetry of protein localization maintained the leading edge and considerably enhanced the persistence of directed migration, and overall random exploration was ensured by switching among the different ordered patterns. Our findings suggest that Dictyostelium cells spontaneously create the ordered patterns of cell shape mediated by PI3K/PTEN/F-actin and control the direction of cell movement by coordination with these patterns even in the absence of external stimuli.

Deadlines in space: Selective effects of coordinate spatial processing in multitasking.

Science.gov (United States)

Todorov, Ivo; Del Missier, Fabio; Konke, Linn Andersson; Mäntylä, Timo

2015-11-01

Many everyday activities require coordination and monitoring of multiple deadlines. One way to handle these temporal demands might be to represent future goals and deadlines as a pattern of spatial relations. We examined the hypothesis that spatial ability, in addition to executive functioning, contributes to individual differences in multitasking. In two studies, participants completed a multitasking session in which they monitored four digital clocks running at different rates. In Study 1, we found that individual differences in spatial ability and executive functions were independent predictors of multiple-task performance. In Study 2, we found that individual differences in specific spatial abilities were selectively related to multiple-task performance, as only coordinate spatial processing, but not categorical, predicted multitasking, even beyond executive functioning and numeracy. In both studies, males outperformed females in spatial ability and multitasking and in Study 2 these sex differences generalized to a simulation of everyday multitasking. Menstrual changes moderated the effects on multitasking, in that sex differences in coordinate spatial processing and multitasking were observed between males and females in the luteal phase of the menstrual cycle, but not between males and females at menses. Overall, these findings suggest that multiple-task performance reflects independent contributions of spatial ability and executive functioning. Furthermore, our results support the distinction of categorical versus coordinate spatial processing, and suggest that these two basic relational processes are selectively affected by female sex hormones and differentially effective in transforming and handling temporal patterns as spatial relations in the context of multitasking.

Coordination and synchronisation of anti-predation vigilance in two crane species.

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Chen Ge

Full Text Available Much of the previous research on anti-predation vigilance in groups has assumed independent scanning for threats among group members. Alternative patterns that are based on monitoring the vigilance levels of companions can also be adaptive. Coordination of vigilance, in which foragers avoid scanning at the same time as others, should decrease the odds that no group member is alert. Synchronisation of vigilance implies that individuals are more likely to be vigilant when companions are already vigilant. While synchronisation will increase the odds that no one is vigilant, it may allow a better assessment of potential threats. We investigated temporal sequences of vigilance in family flocks consisting of two parents and at most two juveniles in two species of cranes in coastal China. We established whether the observed probability that at least one parent is alert was greater (coordination or lower (synchronisation than that predicted under the null hypothesis of independent vigilance. We documented coordination of vigilance in common cranes (Grus grus foraging in an area with high potential for disturbance by people. We documented synchronisation of vigilance in red-crowned cranes (Grus japonensis in the less but not in the more disturbed area. Coordination in small flocks leads to high collective vigilance but low foraging rates that may not be suitable in areas with low disturbance. We also argue that synchronisation should break down in areas with high disturbance because periods with low vigilance are riskier. Results highlight the view that temporal patterns of vigilance can take many forms depending on ecological factors.

Coordination and synchronisation of anti-predation vigilance in two crane species.

Science.gov (United States)

Ge, Chen; Beauchamp, Guy; Li, Zhongqiu

2011-01-01

Much of the previous research on anti-predation vigilance in groups has assumed independent scanning for threats among group members. Alternative patterns that are based on monitoring the vigilance levels of companions can also be adaptive. Coordination of vigilance, in which foragers avoid scanning at the same time as others, should decrease the odds that no group member is alert. Synchronisation of vigilance implies that individuals are more likely to be vigilant when companions are already vigilant. While synchronisation will increase the odds that no one is vigilant, it may allow a better assessment of potential threats. We investigated temporal sequences of vigilance in family flocks consisting of two parents and at most two juveniles in two species of cranes in coastal China. We established whether the observed probability that at least one parent is alert was greater (coordination) or lower (synchronisation) than that predicted under the null hypothesis of independent vigilance. We documented coordination of vigilance in common cranes (Grus grus) foraging in an area with high potential for disturbance by people. We documented synchronisation of vigilance in red-crowned cranes (Grus japonensis) in the less but not in the more disturbed area. Coordination in small flocks leads to high collective vigilance but low foraging rates that may not be suitable in areas with low disturbance. We also argue that synchronisation should break down in areas with high disturbance because periods with low vigilance are riskier. Results highlight the view that temporal patterns of vigilance can take many forms depending on ecological factors.

Neurons in Primary Motor Cortex Encode Hand Orientation in a Reach-to-Grasp Task.

Science.gov (United States)

Ma, Chaolin; Ma, Xuan; Fan, Jing; He, Jiping

2017-08-01

It is disputed whether those neurons in the primary motor cortex (M1) that encode hand orientation constitute an independent channel for orientation control in reach-to-grasp behaviors. Here, we trained two monkeys to reach forward and grasp objects positioned in the frontal plane at different orientation angles, and simultaneously recorded the activity of M1 neurons. Among the 2235 neurons recorded in M1, we found that 18.7% had a high correlation exclusively with hand orientation, 15.9% with movement direction, and 29.5% with both movement direction and hand orientation. The distributions of neurons encoding hand orientation and those encoding movement direction were not uniform but coexisted in the same region. The trajectory of hand rotation was reproduced by the firing patterns of the orientation-related neurons independent of the hand reaching direction. These results suggest that hand orientation is an independent component for the control of reaching and grasping activity.

On the use of polar coordinate system in the projective graphic drawings

Directory of Open Access Journals (Sweden)

Ivashchenko Andrey Viktorovich

2016-11-01

Full Text Available Projective graphics is a polyhedra simulation method, which is based on the use of trace diagrams of initial polyhedron. Previously developed computer software allows using Cartesian coordinates. In some cases it is advisable to use polar coordinate system for description of projective graphics drawings. Using the example of icosahedron the authors analyzed the advantages of using projective graphics drawings in the polar coordinate system. The transition to the polar coordinate system is a tool that allows using certain patterns of projective graphics drawings in the process of calculation. When using polar coordinate system the search of Polar correspondence for the directs is simplified. In order to analyze the two lines in the polar coordinate system it is enough to compare the corresponding coefficients of the equations of these lines. The authors consider a diagram of the icosahedron in polar coordinates, and a corresponding fragment of calculation program in the Mathematica system. Some examples of forming based on icosahedrons are offered. Optimization of computer programs using polar coordinate system will simplifies the calculations of projective graphics drawings, accelerates the process of constructing three-dimensional models, which expand the possibilities of selecting original solutions. Finally, the authors conclude that it is appropriate to use the polar coordinate system only in the construction of projective graphics diagrams of the planes system having rich symmetry. All Platonic and Archimedean solids, Catalan solid possess this property.

Motor Imagery-Based Brain-Computer Interface Coupled to a Robotic Hand Orthosis Aimed for Neurorehabilitation of Stroke Patients

Directory of Open Access Journals (Sweden)

Jessica Cantillo-Negrete

2018-01-01

Full Text Available Motor imagery-based brain-computer interfaces (BCI have shown potential for the rehabilitation of stroke patients; however, low performance has restricted their application in clinical environments. Therefore, this work presents the implementation of a BCI system, coupled to a robotic hand orthosis and driven by hand motor imagery of healthy subjects and the paralysed hand of stroke patients. A novel processing stage was designed using a bank of temporal filters, the common spatial pattern algorithm for feature extraction and particle swarm optimisation for feature selection. Offline tests were performed for testing the proposed processing stage, and results were compared with those computed with common spatial patterns. Afterwards, online tests with healthy subjects were performed in which the orthosis was activated by the system. Stroke patients’ average performance was 74.1 ± 11%. For 4 out of 6 patients, the proposed method showed a statistically significant higher performance than the common spatial pattern method. Healthy subjects’ average offline and online performances were of 76.2 ± 7.6% and 70 ± 6.7, respectively. For 3 out of 8 healthy subjects, the proposed method showed a statistically significant higher performance than the common spatial pattern method. System’s performance showed that it has a potential to be used for hand rehabilitation of stroke patients.

Robotic hand project

OpenAIRE

Karaçizmeli, Cengiz; Çakır, Gökçe; Tükel, Dilek

2014-01-01

In this work, the mechatronic based robotic hand is controlled by the position data taken from the glove which has flex sensors mounted to capture finger bending of the human hand. The angular movement of human hand’s fingers are perceived and processed by a microcontroller, and the robotic hand is controlled by actuating servo motors. It has seen that robotic hand can simulate the movement of the human hand that put on the glove, during tests have done. This robotic hand can be used not only...

Robotic approaches for rehabilitation of hand function after stroke.

Science.gov (United States)

Lum, Peter S; Godfrey, Sasha B; Brokaw, Elizabeth B; Holley, Rahsaan J; Nichols, Diane

2012-11-01

The goal of this review was to discuss the impairments in hand function after stroke and present previous work on robot-assisted approaches to movement neurorehabilitation. Robotic devices offer a unique training environment that may enhance outcomes beyond what is possible with conventional means. Robots apply forces to the hand, allowing completion of movements while preventing inappropriate movement patterns. Evidence from the literature is emerging that certain characteristics of the human-robot interaction are preferable. In light of this evidence, the robotic hand devices that have undergone clinical testing are reviewed, highlighting the authors' work in this area. Finally, suggestions for future work are offered. The ability to deliver therapy doses far higher than what has been previously tested is a potentially key advantage of robotic devices that needs further exploration. In particular, more efforts are needed to develop highly motivating home-based devices, which can increase access to high doses of assisted movement therapy.

Lateralization of brain activity pattern during unilateral movement in Parkinson's disease.

Science.gov (United States)

Wu, Tao; Hou, Yanan; Hallett, Mark; Zhang, Jiarong; Chan, Piu

2015-05-01

We investigated the lateralization of brain activity pattern during performance of unilateral movement in drug-naïve Parkinson's disease (PD) patients with only right hemiparkinsonian symptoms. Functional MRI was obtained when the subjects performed strictly unilateral right hand movement. A laterality index was calculated to examine the lateralization. Patients had decreased activity in the left putamen and left supplementary motor area, but had increased activity in the right primary motor cortex, right premotor cortex, left postcentral gyrus, and bilateral cerebellum. The laterality index was significantly decreased in PD patients compared with controls (0.41 ± 0.14 vs. 0.84 ± 0.09). The connectivity from the left putamen to cortical motor regions and cerebellum was decreased, while the interactions between the cortical motor regions, cerebellum, and right putamen were increased. Our study demonstrates that in early PD, the lateralization of brain activity during unilateral movement is significantly reduced. The dysfunction of the striatum-cortical circuit, decreased transcallosal inhibition, and compensatory efforts from cortical motor regions, cerebellum, and the less affected striatum are likely reasons contributing to the reduced motor lateralization. The disruption of the lateralized brain activity pattern might be a reason underlying some motor deficits in PD, like mirror movements or impaired bilateral motor coordination. © 2015 Wiley Periodicals, Inc.

Pattern formation in optical resonators

International Nuclear Information System (INIS)

Weiss, C O; Larionova, Ye

2007-01-01

We review pattern formation in optical resonators. The emphasis is on 'particle-like' structures such as vortices or spatial solitons. On the one hand, similarities impose themselves with other fields of physics (condensed matter, phase transitions, particle physics, fluds/super fluids). On the other hand the feedback is led by the resonator mirrors to bi- and multi-stability of the spatial field structure, which is the basic ingredient for optical information processing. The spatial dimension or the 'parallelism' is the strength of optics compared to electronics (and will have to be employed to fully use the advantages optics offers in information processing). But even in the 'serial' processing tasks of telecoms (e.g. information buffering) spatial resonator solitons can do better than the schemes proposed so far-including 'slow light'. Pattern formation in optical resonators will likely be the key to brain-like information processing like cognition, learning and association; to complement the precise but limited algorithmic capabilities of electronic processing. But even in the short term it will be useful for solving serial optical processing problems. The prospects for technical uses of pattern formation in resonators are one motivation for this research. The fundamental similarities with other fields of physics, on the other hand, inspire transfer of concepts between fields; something that has always proven fruitful for gaining deeper insights or for solving technical problems

Clean Hands Count

Medline Plus

Full Text Available ... has been rented. This feature is not available right now. Please try again later. Published on May ... 34 How The Clean Hands - Safe Hands System Works - Duration: 3:38. Clean Hands-Safe Hands 5, ...

Robotic Exoskeletons: A Perspective for the Rehabilitation of Arm Coordination in Stroke Patients

Science.gov (United States)

Jarrassé, Nathanaël; Proietti, Tommaso; Crocher, Vincent; Robertson, Johanna; Sahbani, Anis; Morel, Guillaume; Roby-Brami, Agnès

2014-01-01

Upper-limb impairment after stroke is caused by weakness, loss of individual joint control, spasticity, and abnormal synergies. Upper-limb movement frequently involves abnormal, stereotyped, and fixed synergies, likely related to the increased use of sub-cortical networks following the stroke. The flexible coordination of the shoulder and elbow joints is also disrupted. New methods for motor learning, based on the stimulation of activity-dependent neural plasticity have been developed. These include robots that can adaptively assist active movements and generate many movement repetitions. However, most of these robots only control the movement of the hand in space. The aim of the present text is to analyze the potential of robotic exoskeletons to specifically rehabilitate joint motion and particularly inter-joint coordination. First, a review of studies on upper-limb coordination in stroke patients is presented and the potential for recovery of coordination is examined. Second, issues relating to the mechanical design of exoskeletons and the transmission of constraints between the robotic and human limbs are discussed. The third section considers the development of different methods to control exoskeletons: existing rehabilitation devices and approaches to the control and rehabilitation of joint coordinations are then reviewed, along with preliminary clinical results available. Finally, perspectives and future strategies for the design of control mechanisms for rehabilitation exoskeletons are discussed. PMID:25520638

Evaluating fine motor coordination in children who are not ready for handwriting : which test should we take?

NARCIS (Netherlands)

de Vries, Liesbeth; van Hartingsveldt, Margo J.; Cup, Edith H.C.; Nijhuis-van der Sanden, Maria W.G.; de Groot, Imelda J.M.

2015-01-01

When children are not ready to write, assessment of fine motor coordination may be indicated. The purpose of this study was to evaluate which fine motor test, the Nine-Hole Peg Test (9-HPT) or the newly developed Timed Test of In-Hand Manipulation (Timed-TIHM), correlates best with handwriting

Evaluating fine motor coordination in children who are not ready for handwriting: which test should we take?

NARCIS (Netherlands)

Vries, L. de; Hartingsveldt, M.J. van; Cup, E.H.C.; Nijhuis-Van der Sanden, M.W.G.; Groot, I.J.M. de

2015-01-01

When children are not ready to write, assessment of fine motor coordination may be indicated. The purpose of this study was to evaluate which fine motor test, the Nine-Hole Peg Test (9-HPT) or the newly developed Timed Test of In-Hand Manipulation (Timed-TIHM), correlates best with handwriting

Overcurrent protection co-ordination. A modern approach for modern devices

Energy Technology Data Exchange (ETDEWEB)

Hindle, P. [GEC Alsthom Engineering Systems Ltd., Whetstone (United Kingdom); Sanderson, J.V.H. [Power Engineering Consultants Ltd., Cheshire (United Kingdom)

1995-12-31

A modern approach to relay co-ordination that takes advantage of the improved performance of modern protective relays and circuits was proposed. The proposed method dealt with a mixture of new and old equipment and was most useful when implemented using common spreadsheet software. The suggested approach justified reduced time margins for relay co-ordination in many difficult applications. Other established approaches were reviewed. A discussion of fixed and variable time margin allowances was presented. The formulation of an equation to determine the required upstream relay operating time was explained, with sample calculations. Relay performance standards and modern protective equipment were discussed. It was concluded that modern relays and circuit breakers are much more advanced than designs of the recent past. The method described allowed significant reductions in margins which enabled modern relays to operate faster. While calculations for the procedures were said to be tedious to perform by hand, they can be easily done with spreadsheet software. 10 refs., 4 figs.

Temporal predictive mechanisms modulate motor reaction time during initiation and inhibition of speech and hand movement.

Science.gov (United States)

Johari, Karim; Behroozmand, Roozbeh

2017-08-01

Skilled movement is mediated by motor commands executed with extremely fine temporal precision. The question of how the brain incorporates temporal information to perform motor actions has remained unanswered. This study investigated the effect of stimulus temporal predictability on response timing of speech and hand movement. Subjects performed a randomized vowel vocalization or button press task in two counterbalanced blocks in response to temporally-predictable and unpredictable visual cues. Results indicated that speech and hand reaction time was decreased for predictable compared with unpredictable stimuli. This finding suggests that a temporal predictive code is established to capture temporal dynamics of sensory cues in order to produce faster movements in responses to predictable stimuli. In addition, results revealed a main effect of modality, indicating faster hand movement compared with speech. We suggest that this effect is accounted for by the inherent complexity of speech production compared with hand movement. Lastly, we found that movement inhibition was faster than initiation for both hand and speech, suggesting that movement initiation requires a longer processing time to coordinate activities across multiple regions in the brain. These findings provide new insights into the mechanisms of temporal information processing during initiation and inhibition of speech and hand movement. Copyright © 2017 Elsevier B.V. All rights reserved.

A feasibility study of hand kinematics for EVA analysis using magnetic resonance imaging

Science.gov (United States)

Dickenson, Rueben D.; Lorenz, Christine H.; Peterson, Steven W.; Strauss, Alvin M.; Main, John A.

1992-01-01

A new method of analyzing the kinematics of joint motion is developed. Magnetic Resonance Imaging (MRI) offers several distinct advantages. Past methods of studying anatomic joint motion have usually centered on four approaches. These methods are x-ray projection, goniometric linkage analysis, sonic digitization, and landmark measurement of photogrammetry. Of these four, only x-ray is applicable for in vivo studies. The remaining three methods utilize other types of projections of inter-joint measurements, which can cause various types of error. MRI offers accuracy in measurement due to its tomographic nature (as opposed to projection) without the problems associated with x-ray dosage. Once the data acquisition of MR images was complete, the images were processed using a 3D volume rendering workstation. The metacarpalphalangeal (MCP) joint of the left index finger was selected and reconstructed into a three-dimensional graphic display. From the reconstructed volumetric images, measurements of the angles of movement of the applicable bones were obtained and processed by analyzing the screw motion of the MCP joint. Landmark positions were chosen at distinctive locations of the joint at fixed image threshold intensity levels to ensure repeatability. The primarily two dimensional planar motion of this joint was then studied using a method of constructing coordinate systems using three (or more) points. A transformation matrix based on a world coordinate system described the location and orientation of a local target coordinate system. Future research involving volume rendering of MRI data focusing on the internal kinematics of the hand's individual ligaments, cartilage, tendons, etc. will follow. Its findings will show the applicability of MRI to joint kinematics for gaining further knowledge of the hand-glove (power assisted) design for extravehicular activity (EVA).

An Alternative Myoelectric Pattern Recognition Approach for the Control of Hand Prostheses: A Case Study of Use in Daily Life by a Dysmelia Subject

Science.gov (United States)

Ahlberg, Johan; Lendaro, Eva; Hermansson, Liselotte; Håkansson, Bo; Ortiz-Catalan, Max

2018-01-01

The functionality of upper limb prostheses can be improved by intuitive control strategies that use bioelectric signals measured at the stump level. One such strategy is the decoding of motor volition via myoelectric pattern recognition (MPR), which has shown promising results in controlled environments and more recently in clinical practice. Moreover, not much has been reported about daily life implementation and real-time accuracy of these decoding algorithms. This paper introduces an alternative approach in which MPR allows intuitive control of four different grips and open/close in a multifunctional prosthetic hand. We conducted a clinical proof-of-concept in activities of daily life by constructing a self-contained, MPR-controlled, transradial prosthetic system provided with a novel user interface meant to log errors during real-time operation. The system was used for five days by a unilateral dysmelia subject whose hand had never developed, and who nevertheless learned to generate patterns of myoelectric activity, reported as intuitive, for multi-functional prosthetic control. The subject was instructed to manually log errors when they occurred via the user interface mounted on the prosthesis. This allowed the collection of information about prosthesis usage and real-time classification accuracy. The assessment of capacity for myoelectric control test was used to compare the proposed approach to the conventional prosthetic control approach, direct control. Regarding the MPR approach, the subject reported a more intuitive control when selecting the different grips, but also a higher uncertainty during proportional continuous movements. This paper represents an alternative to the conventional use of MPR, and this alternative may be particularly suitable for a certain type of amputee patients. Moreover, it represents a further validation of MPR with dysmelia cases. PMID:29637030

The relative timing between eye and hand rapid sequential pointing is affected by time pressure, but not by advance knowledge

NARCIS (Netherlands)

Deconinck, F.; van Polanen, V.; Savelsbergh, G.J.P.; Bennett, S.

2011-01-01

The present study examined the effect of timing constraints and advance knowledge on eye-hand coordination strategy in a sequential pointing task. Participants were required to point at two successively appearing targets on a screen while the inter-stimulus interval (ISI) and the trial order were

Compensatory motor control after stroke: an alternative joint strategy for object-dependent shaping of hand posture.

Science.gov (United States)

Raghavan, Preeti; Santello, Marco; Gordon, Andrew M; Krakauer, John W

2010-06-01

Efficient grasping requires planned and accurate coordination of finger movements to approximate the shape of an object before contact. In healthy subjects, hand shaping is known to occur early in reach under predominantly feedforward control. In patients with hemiparesis after stroke, execution of coordinated digit motion during grasping is impaired as a result of damage to the corticospinal tract. The question addressed here is whether patients with hemiparesis are able to compensate for their execution deficit with a qualitatively different grasp strategy that still allows them to differentiate hand posture to object shape. Subjects grasped a rectangular, concave, and convex object while wearing an instrumented glove. Reach-to-grasp was divided into three phases based on wrist kinematics: reach acceleration (reach onset to peak horizontal wrist velocity), reach deceleration (peak horizontal wrist velocity to reach offset), and grasp (reach offset to lift-off). Patients showed reduced finger abduction, proximal interphalangeal joint (PIP) flexion, and metacarpophalangeal joint (MCP) extension at object grasp across all three shapes compared with controls; however, they were able to partially differentiate hand posture for the convex and concave shapes using a compensatory strategy that involved increased MCP flexion rather than the PIP flexion seen in controls. Interestingly, shape-specific hand postures did not unfold initially during reach acceleration as seen in controls, but instead evolved later during reach deceleration, which suggests increased reliance on sensory feedback. These results indicate that kinematic analysis can identify and quantify within-limb compensatory motor control strategies after stroke. From a clinical perspective, quantitative study of compensation is important to better understand the process of recovery from brain injury. From a motor control perspective, compensation can be considered a model for how joint redundancy is exploited

Development of a parametric kinematic model of the human hand and a novel robotic exoskeleton.

Science.gov (United States)

Burton, T M W; Vaidyanathan, R; Burgess, S C; Turton, A J; Melhuish, C

2011-01-01

This paper reports the integration of a kinematic model of the human hand during cylindrical grasping, with specific focus on the accurate mapping of thumb movement during grasping motions, and a novel, multi-degree-of-freedom assistive exoskeleton mechanism based on this model. The model includes thumb maximum hyper-extension for grasping large objects (~> 50 mm). The exoskeleton includes a novel four-bar mechanism designed to reproduce natural thumb opposition and a novel synchro-motion pulley mechanism for coordinated finger motion. A computer aided design environment is used to allow the exoskeleton to be rapidly customized to the hand dimensions of a specific patient. Trials comparing the kinematic model to observed data of hand movement show the model to be capable of mapping thumb and finger joint flexion angles during grasping motions. Simulations show the exoskeleton to be capable of reproducing the complex motion of the thumb to oppose the fingers during cylindrical and pinch grip motions. © 2011 IEEE

Hand Hygiene With Alcohol-Based Hand Rub: How Long Is Long Enough?

Science.gov (United States)

Pires, Daniela; Soule, Hervé; Bellissimo-Rodrigues, Fernando; Gayet-Ageron, Angèle; Pittet, Didier

2017-05-01

BACKGROUND Hand hygiene is the core element of infection prevention and control. The optimal hand-hygiene gesture, however, remains poorly defined. OBJECTIVE We aimed to evaluate the influence of hand-rubbing duration on the reduction of bacterial counts on the hands of healthcare personnel (HCP). METHODS We performed an experimental study based on the European Norm 1500. Hand rubbing was performed for 10, 15, 20, 30, 45, or 60 seconds, according to the WHO technique using 3 mL alcohol-based hand rub. Hand contamination with E. coli ATCC 10536 was followed by hand rubbing and sampling. A generalized linear mixed model with a random effect on the subject adjusted for hand size and gender was used to analyze the reduction in bacterial counts after each hand-rubbing action. In addition, hand-rubbing durations of 15 and 30 seconds were compared to assert non-inferiority (0.6 log10). RESULTS In total, 32 HCP performed 123 trials. All durations of hand rubbing led to significant reductions in bacterial counts (Phand rubbing were not significantly different from those obtained after 30 seconds. The mean bacterial reduction after 15 seconds of hand rubbing was 0.11 log10 lower (95% CI, -0.46 to 0.24) than after 30 seconds, demonstrating non-inferiority. CONCLUSIONS Hand rubbing for 15 seconds was not inferior to 30 seconds in reducing bacterial counts on hands under the described experimental conditions. There was no gain in reducing bacterial counts from hand rubbing longer than 30 seconds. Further studies are needed to assess the clinical significance of our findings. Infect Control Hosp Epidemiol 2017;38:547-552.

Impaired Interlimb Coordination of Voluntary Leg Movements in Poststroke Hemiparesis

Science.gov (United States)

Tseng, Shih-Chiao

2010-01-01

Appropriate interlimb coordination of the lower extremities is particularly important for a variety of functional human motor behaviors such as jumping, kicking a ball, or simply walking. Specific interlimb coordination patterns may be especially impaired after a lesion to the motor system such as stroke, yet this has not been thoroughly examined to date. The purpose of this study was to investigate the motor deficits in individuals with chronic stroke and hemiparesis when performing unilateral versus bilateral inphase versus bilateral antiphase voluntary cyclic ankle movements. We recorded ankle angular trajectories and muscle activity from the dorsiflexors and plantarflexors and compared these between subjects with stroke and a group of healthy age-matched control subjects. Results showed clear abnormalities in both the kinematics and EMG of the stroke subjects, with significant movement degradation during the antiphase task compared with either the unilateral or the inphase task. The abnormalities included prolonged cycle durations, reduced ankle excursions, decreased agonist EMG bursts, and reduced EMG modulation across movement phases. By comparison, the control group showed nearly identical performance across all task conditions. These findings suggest that stroke involving the corticospinal system projection to the leg specifically impairs one or more components of the neural circuitry involved in lower extremity interlimb coordination. The express susceptibility of the antiphase pattern to exaggerated motor deficits could contribute to functional deficits in a number of antiphase leg movement tasks, including walking. PMID:20463199

Hand in Hand - SEI Programmes for School Staff

DEFF Research Database (Denmark)

Nielsen, Birgitte Lund; Réol, Lise Andersen; Laursen, Hilmar Dyrborg

2017-01-01

This catalogue of research in the field of SEI programmes for the school staff’s and teachers’ SEI competencies is based on a review performed by the main researchers Birgitte Lund Nielsen, Lise Andersen Réol and Hilmar Dyrborg Laursen, VIA University College, Denmark, but discussed by the entire...... team of Hand in Hand partner countries and researchers. The aim was to identify the central aspects and elements concerning successful implementation, and school staff’s development of professional competencies in the specific field of supporting students’ social, emotional and intercultural (SEI......) competencies. Abstract: Framed by the EU-project Hand in Hand focusing on Social, Emotional and Intercultural (SEI) competencies among students and school staff, the paper discusses implementation and professional competencies based on a research review. The following five topics were identified: 1...

Changes in muscle coordination with training.

Science.gov (United States)

Carson, Richard G

2006-11-01

Three core concepts, activity-dependent coupling, the composition of muscle synergies, and Hebbian adaptation, are discussed with a view to illustrating the nature of the constraints imposed by the organization of the central nervous system on the changes in muscle coordination induced by training. It is argued that training invoked variations in the efficiency with which motor actions can be generated influence the stability of coordination by altering the potential for activity-dependent coupling between the cortical representations of the focal muscles recruited in a movement task and brain circuits that do not contribute directly to the required behavior. The behaviors that can be generated during training are also constrained by the composition of existing intrinsic muscle synergies. In circumstances in which attempts to produce forceful or high velocity movements would otherwise result in the generation of inappropriate actions, training designed to promote the development of control strategies specific to the desired movement outcome may be necessary to compensate for protogenic muscle recruitment patterns. Hebbian adaptation refers to processes whereby, for neurons that release action potentials at the same time, there is an increased probability that synaptic connections will be formed. Neural connectivity induced by the repetition of specific muscle recruitment patterns during training may, however, inhibit the subsequent acquisition of new skills. Consideration is given to the possibility that, in the presence of the appropriate sensory guidance, it is possible to gate Hebbian plasticity and to promote greater subsequent flexibility in the recruitment of the trained muscles in other task contexts.

Cortical Reorganization after Hand Immobilization: The beta qEEG Spectral Coherence Evidences

Science.gov (United States)

Fortuna, Marina; Teixeira, Silmar; Machado, Sérgio; Velasques, Bruna; Bittencourt, Juliana; Peressutti, Caroline; Budde, Henning; Cagy, Mauricio; Nardi, Antonio E.; Piedade, Roberto; Ribeiro, Pedro; Arias-Carrión, Oscar

2013-01-01

There is increasing evidence that hand immobilization is associated with various changes in the brain. Indeed, beta band coherence is strongly related to motor act and sensitive stimuli. In this study we investigate the electrophysiological and cortical changes that occur when subjects are submitted to hand immobilization. We hypothesized that beta coherence oscillations act as a mechanism underlying inter- and intra-hemispheric changes. As a methodology for our study fifteen healthy individuals between the ages of 20 and 30 years were subjected to a right index finger task before and after hand immobilization while their brain activity pattern was recorded using quantitative electroencephalography. This analysis revealed that hand immobilization caused changes in frontal, central and parietal areas of the brain. The main findings showed a lower beta-2 band in frontal regions and greater cortical activity in central and parietal areas. In summary, the coherence increased in the frontal, central and parietal cortex, due to hand immobilization and it adjusted the brains functioning, which had been disrupted by the procedure. Moreover, the brain adaptation upon hand immobilization of the subjects involved inter- and intra-hemispheric changes. PMID:24278213

Between fragmented authoritarianism and policy coordination: Creating a Chinese market for wind energy

International Nuclear Information System (INIS)

Lema, Adrian; Ruby, Kristian

2007-01-01

The Chinese grid-connected wind energy sector has undergone a number of fundamental changes during its 20 years of existence. The scope of this article is to track the reforms of the energy bureaucracy and its policy approach on the one hand and changes in wind energy installations on the other. By comparing three historically distinct phases of wind energy in China it is shown how policy reforms have changed largely from a state of 'fragmented authoritarianism' towards policy coordination. In the initial phase (1986-1993), wind energy was expanding very slowly with disjointed policy making and in the incremental phase (1994-1999), the energy authorities were in dispute over the strategy and launched conflicting policy initiatives with poor results in wind energy output. The latest coordinated phase (2000-2006), however, developed a coherent renewable energy agenda and policy regime for the wind power sector. It is found that this phase with coordinated market regulations and incentives has helped give birth to a take-off in Chinese wind energy installations and substantial cost reductions, although the latter is threatening the profitability of wind farms. The article contributes to the academic debate over the role of policy making in renewable energy development and argues that China should continue, and improve, the coordination of regulations and incentives

Considering Pilot Protection in the Optimal Coordination of Distance and Directional Overcurrent Relays

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Y. Damchi

2015-06-01

Full Text Available The aim of the relay coordination is that protection systems detect and isolate the faulted part as fast and selective as possible. On the other hand, in order to reduce the fault clearing time, distance protection relays are usually equipped with pilot protection schemes. Such schemes can be considered in the distance and directional overcurrent relays (D&DOCRs coordination to achieve faster protection systems, while the selectivity is maintained. Therefore, in this paper, a new formulation is presented for the relay coordination problem considering pilot protection. In the proposed formulation, the selectivity constraints for the primary distance and backup overcurrent relays are defined based on the fault at the end of the transmission lines, rather than those at the end of the first zone of the primary distance relay. To solve this nonlinear optimization problem, a combination of genetic algorithm (GA and linear programming (LP is used as a hybrid genetic algorithm (HGA. The proposed approach is tested on an 8-bus and the IEEE 14-bus test systems. Simulation results indicate that considering the pilot protection in the D&DOCRS coordination, not only obtains feasible and effective solutions for the relay settings, but also reduces the overall operating time of the protection system.

Virtual Incision Pattern Planning using Three-Dimensional Images for Optimization of Syndactyly Surgery

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Inge A. Hoevenaren, MD

2018-03-01

Full Text Available Summary:. Syndactyly is a congenital condition characterized by fusion of the fingers. If not treated correctly during infancy, syndactyly may hinder the normal development of hand function. Many surgical techniques have been developed, with the main goal to create a functional hand with the smallest number of operative corrections. Therefore, exact preoperative planning of the reconstructive procedure is essential. An imaging method commonly used for preoperative planning is 3-dimensional (3D surface imaging. The goal of this study was to implement the use of this technique in hand surgery, by designing a virtual planning tool for a desyndactylization procedure based on 3D hand images. A 3D image of a silicon syndactyly model was made on which the incision pattern was virtually designed. A surgical template of this pattern was printed, placed onto the silicon model and delineated. The accuracy of the transfer from the virtual delineation toward the real delineation was calculated, resulting in a mean difference of 0.82 mm. This first step indicates that by using 3D images, a virtual incision pattern can be created and transferred back onto the patient successfully in an easy and accurate way by using a template. Thereafter, 3D hand images of 3 syndactyly patients were made, and individual virtual incision patterns were created. Each pattern was transferred onto the patient by using a 3D printed template. The resulting incision pattern needed minor modifications by the surgeon before the surgery was performed. Further research and validation are necessary to develop the virtual planning of desyndactylization procedures.

Guideline Implementation: Hand Hygiene.

Science.gov (United States)

Goldberg, Judith L

2017-02-01

Performing proper hand hygiene and surgical hand antisepsis is essential to reducing the rates of health care-associated infections, including surgical site infections. The updated AORN "Guideline for hand hygiene" provides guidance on hand hygiene and surgical hand antisepsis, the wearing of fingernail polish and artificial nails, proper skin care to prevent dermatitis, the wearing of jewelry, hand hygiene product selection, and quality assurance and performance improvement considerations. This article focuses on key points of the guideline to help perioperative personnel make informed decisions about hand hygiene and surgical hand antisepsis. The key points address the necessity of keeping fingernails and skin healthy, not wearing jewelry on the hands or wrists in the perioperative area, properly performing hand hygiene and surgical hand antisepsis, and involving patients and visitors in hand hygiene initiatives. Perioperative RNs should review the complete guideline for additional information and for guidance when writing and updating policies and procedures. Copyright © 2017 AORN, Inc. Published by Elsevier Inc. All rights reserved.

Good and bad in the hands of politicians: spontaneous gestures during positive and negative speech.

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Daniel Casasanto

2010-07-01

Full Text Available According to the body-specificity hypothesis, people with different bodily characteristics should form correspondingly different mental representations, even in highly abstract conceptual domains. In a previous test of this proposal, right- and left-handers were found to associate positive ideas like intelligence, attractiveness, and honesty with their dominant side and negative ideas with their non-dominant side. The goal of the present study was to determine whether 'body-specific' associations of space and valence can be observed beyond the laboratory in spontaneous behavior, and whether these implicit associations have visible consequences.We analyzed speech and gesture (3012 spoken clauses, 1747 gestures from the final debates of the 2004 and 2008 US presidential elections, which involved two right-handers (Kerry, Bush and two left-handers (Obama, McCain. Blind, independent coding of speech and gesture allowed objective hypothesis testing. Right- and left-handed candidates showed contrasting associations between gesture and speech. In both of the left-handed candidates, left-hand gestures were associated more strongly with positive-valence clauses and right-hand gestures with negative-valence clauses; the opposite pattern was found in both right-handed candidates.Speakers associate positive messages more strongly with dominant hand gestures and negative messages with non-dominant hand gestures, revealing a hidden link between action and emotion. This pattern cannot be explained by conventions in language or culture, which associate 'good' with 'right' but not with 'left'; rather, results support and extend the body-specificity hypothesis. Furthermore, results suggest that the hand speakers use to gesture may have unexpected (and probably unintended communicative value, providing the listener with a subtle index of how the speaker feels about the content of the co-occurring speech.

Inspections of Hand Washing Supplies and Hand Sanitizer in Public Schools

Science.gov (United States)

Ramos, Mary M.; Blea, Mary; Trujillo, Rebecca; Greenberg, Cynthia

2010-01-01

Hand washing and hand antisepsis are proven infection control measures in the school setting, yet barriers such as lack of soap, paper towels, and hand sanitizer can hinder compliance. This pilot study measured the prevalence of hand cleaning supplies in public schools. Ten school districts (93 schools) participated in school nurse inspections. In…

Somatic sensory cortex (SmI) of the prosimian primate Galago crassicaudatus: organization of mechanoreceptive input from the hand in relation to cytoarchitecture.

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Carlson, M; Welt, C

1980-01-15

Mechanoreceptive input from the hand to the somatic sensory cortex (SmI) of the prosimian primate Galago crassicaudatus was examined with microelectrode mapping methods. In anesthetized animals, low threshold cutaneous input from the hand projects to SmI cortex in a single, complete, somatotopically organized pattern. Within this single pattern, cells with receptive fields on the glabrous skin of the palm, digits and digit tips are located in the rostral half, and cells with RFs on the hairy skin of the dorsal hand and digits are located in the caudal half of the hand areas. The cutaneous hand area is coextensive with the densely granular architectonic region of SmI. Studies of single cells in this region of awake galagos reveal the same pattern of cutaneous input and, in addition, demonstrate the presence of cells responding to joint movement not detected in anesthetized animals. Cells responsive to joint movement are arranged in vertically oriented columns located adjacent to cutaneous columns with receptive fields on the same part of the hand. In anesthetized animals, cells rostral to the granular region, in an area typified by increasing numbers of pyramidal cells in layer V and decreasing numbers of granular cells in upper layers, respond to high threshold stimulation of large areas of the hand. The few cells isolated in this area in awake animals respond to either active or passive hand movements. In such animals, cells caudal to the granular region, in an area characterized as agranular and alaminar cortex, respond to either passive stimulation of single or multiple joints or to active hand movements. These results, together with similar findings in a related prosimian, Nycticebus coucang, emphasize the generality of a single cutaneous hand area in SmI of prosimian species. The demonstration of multiple hand areas corresponding to multiple cytoarchitectonic subdivisions in SmI of Old and New World simians illustrates the increased degree of Sm

Effect of hand sanitizer location on hand hygiene compliance.

Science.gov (United States)

Cure, Laila; Van Enk, Richard

2015-09-01

Hand hygiene is the most important intervention to prevent infection in hospitals. Health care workers should clean their hands at least before and after contact with patients. Hand sanitizer dispensers are important to support hand hygiene because they can be made available throughout hospital units. The aim of this study was to determine whether the usability of sanitizer dispensers correlates with compliance of staff in using the sanitizer in a hospital. This study took place in a Midwest, 404-bed, private, nonprofit community hospital with 15 inpatient care units in addition to several ambulatory units. The usability and standardization of sanitizers in 12 participating inpatient units were evaluated. The hospital measured compliance of staff with hand hygiene as part of their quality improvement program. Data from 2010-2012 were analyzed to measure the relationship between compliance and usability using mixed-effects logistic regression models. The total usability score (P = .0046), visibility (P = .003), and accessibility of the sanitizer on entrance to the patient room (P = .00055) were statistically associated with higher observed compliance rates. Standardization alone showed no significant impact on observed compliance (P = .37). Hand hygiene compliance can be influenced by visibility and accessibility of dispensers. The sanitizer location should be part of multifaceted interventions to improve hand hygiene. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

The role of the Australian workplace return to work coordinator: essential qualities and attributes.

Science.gov (United States)

Bohatko-Naismith, Joanna; James, Carole; Guest, Maya; Rivett, Darren A

2015-03-01

In the Australian context, a return to work (RTW) Coordinator assists an injured worker with workplace-based support and regulatory guidance for the duration of their injury. Coordinating the RTW process has been considered an effective approach for managing workplace injuries, however few studies have described the skills, traits or characteristics required to fulfil the role of workplace RTW Coordinator. This study aims to provide insight as to the skills and attributes needed for the role of the workplace RTW Coordinator from their experience and perception. Focus groups were conducted with workplace RTW Coordinators from six major Australian cities. Twenty five participants were recruited through a national RTW Coordinator website, and professional RTW interest groups using a snowballing technique. Participating workplace RTW Coordinators were required to have a minimum 2 years' experience and to have been involved with the development and implementation of workplace policies and procedures. Thematic analysis was performed to identify meaningful patterns and themes. The data analysed provided clear insight as to the specific role requirements necessary for working as an Australian workplace RTW Coordinator. Three key themes clearly emerged; communication skills, RTW Coordinator characteristics, and managing the RTW process. The findings indicate that RTW Coordinators require a wide range of traits, skills, and attributes to successfully perform this role. Effective management by the RTW Coordinator of the complex RTW process is essential to facilitate a smooth transition for the injured worker, alongside maintaining a professional relationship with the employer and external stakeholders. The results of this study can be utilised to further improve the selection of future RTW Coordinators.

Die Sprache der Hande zu den Handen sprechen (Talking the Language of the Hands to the Hands). DB-LINK.

Science.gov (United States)

Miles, Barbara

This paper examines the importance of hands for the person who is deafblind, reviews hand development, and identifies specific teaching skills that facilitate hand development and expressiveness in persons who are deafblind. It notes that the hands of a deafblind individual serve not only as tools but also as sense organs (to compensate for their…

The pattern of skeletal anomalies in the cervical spine, hands and feet in patients with Saethre-Chotzen syndrome and Muenke-type mutation

International Nuclear Information System (INIS)

Trusen, Andreas; Beissert, Matthias; Darge, Kassa; Collmann, Hartmut

2003-01-01

Saethre-Chotzen syndrome (SCS) and Muenke-type mutation (MTM) are complex syndromes with craniosynostosis and skeletal anomalies including syndactyly, carpal and tarsal fusions, and cervical spine abnormalities. In this study, we analysed radiographs of the cervical spine, hands and feet of a large patient population with genetically proven SCS and MTM. The aim was to describe the pattern of skeletal anomalies and to determine whether specific features are present that could help differentiate between the two entities. Radiographs of 43 patients (23 males, 20 females) with SCS (n=35) or MTM (n=8) were evaluated. The median age was 8 years (range 1 month-36 years). All radiographs were reviewed by two radiologists. In the hands and feet, a variety of anomalies such as brachyphalangy, clinodactyly, partial syndactyly, partial carpal or tarsal fusion, and cone-shaped epiphyses were noted. Duplicated distal phalanx of the hallux (n=12/35) and triangular deformity of the epiphysis of the distal phalanx of the hallux (n=10/35) were detected in SCS only; calcaneo-cuboid fusion (n=2/35) was detected in MTM only. In the cervical spine, fusion of vertebral bodies and/or the posterior elements occurred only in patients with SCS. Pathognomonic signs for SCS are the triangular shape of the epiphysis and duplicated distal phalanx of the hallux. Calcaneo-cuboid fusion was detected in MTM only. These signs may be helpful in the differentiation of SCS from MTM. (orig.)

Hand hygiene strategies

OpenAIRE

Yazaji, Eskandar Alex

2011-01-01

Hand hygiene is one of the major players in preventing healthcare associated infections. However, healthcare workers compliance with hand hygiene continues to be a challenge. This article will address strategies to help improving hand hygiene compliance. Keywords: hand hygiene; healthcare associated infections; multidisciplinary program; system change; accountability; education; feedback(Published: 18 July 2011)Citation: Journal of Community Hospital Internal Medicine Perspectives 2011, 1: 72...

The human hand as an inspiration for robot hand development

CERN Document Server

Santos, Veronica

2014-01-01

“The Human Hand as an Inspiration for Robot Hand Development” presents an edited collection of authoritative contributions in the area of robot hands. The results described in the volume are expected to lead to more robust, dependable, and inexpensive distributed systems such as those endowed with complex and advanced sensing, actuation, computation, and communication capabilities. The twenty-four chapters discuss the field of robotic grasping and manipulation viewed in light of the human hand’s capabilities and push the state-of-the-art in robot hand design and control. Topics discussed include human hand biomechanics, neural control, sensory feedback and perception, and robotic grasp and manipulation. This book will be useful for researchers from diverse areas such as robotics, biomechanics, neuroscience, and anthropologists.

The Effects of Upper-Limb Training Assisted with an Electromyography-Driven Neuromuscular Electrical Stimulation Robotic Hand on Chronic Stroke

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Chingyi Nam

2017-12-01

Full Text Available BackgroundImpaired hand dexterity is a major disability of the upper limb after stroke. An electromyography (EMG-driven neuromuscular electrical stimulation (NMES robotic hand was designed previously, whereas its rehabilitation effects were not investigated.ObjectivesThis study aims to investigate the rehabilitation effectiveness of the EMG-driven NMES-robotic hand-assisted upper-limb training on persons with chronic stroke.MethodA clinical trial with single-group design was conducted on chronic stroke participants (n = 15 who received 20 sessions of EMG-driven NMES-robotic hand-assisted upper-limb training. The training effects were evaluated by pretraining, posttraining, and 3-month follow-up assessments with the clinical scores of the Fugl-Meyer Assessment (FMA, the Action Research Arm Test (ARAT, the Wolf Motor Function Test, the Motor Functional Independence Measure, and the Modified Ashworth Scale (MAS. Improvements in the muscle coordination across the sessions were investigated by EMG parameters, including EMG activation level and Co-contraction Indexes (CIs of the target muscles in the upper limb.ResultsSignificant improvements in the FMA shoulder/elbow and wrist/hand scores (P < 0.05, the ARAT (P < 0.05, and in the MAS (P < 0.05 were observed after the training and sustained 3 months later. The EMG parameters indicated a significant decrease of the muscle activation level in flexor digitorum (FD and biceps brachii (P < 0.05, as well as a significant reduction of CIs in the muscle pairs of FD and triceps brachii and biceps brachii and triceps brachii (P < 0.05.ConclusionThe upper-limb training integrated with the assistance from the EMG-driven NMES-robotic hand is effective for the improvements of the voluntary motor functions and the muscle coordination in the proximal and distal joints. Furthermore, the motor improvement after the training could be maintained till 3 months later.Trial registration

The Effects of Upper-Limb Training Assisted with an Electromyography-Driven Neuromuscular Electrical Stimulation Robotic Hand on Chronic Stroke.

Science.gov (United States)

Nam, Chingyi; Rong, Wei; Li, Waiming; Xie, Yunong; Hu, Xiaoling; Zheng, Yongping

2017-01-01

Impaired hand dexterity is a major disability of the upper limb after stroke. An electromyography (EMG)-driven neuromuscular electrical stimulation (NMES) robotic hand was designed previously, whereas its rehabilitation effects were not investigated. This study aims to investigate the rehabilitation effectiveness of the EMG-driven NMES-robotic hand-assisted upper-limb training on persons with chronic stroke. A clinical trial with single-group design was conducted on chronic stroke participants ( n  = 15) who received 20 sessions of EMG-driven NMES-robotic hand-assisted upper-limb training. The training effects were evaluated by pretraining, posttraining, and 3-month follow-up assessments with the clinical scores of the Fugl-Meyer Assessment (FMA), the Action Research Arm Test (ARAT), the Wolf Motor Function Test, the Motor Functional Independence Measure, and the Modified Ashworth Scale (MAS). Improvements in the muscle coordination across the sessions were investigated by EMG parameters, including EMG activation level and Co-contraction Indexes (CIs) of the target muscles in the upper limb. Significant improvements in the FMA shoulder/elbow and wrist/hand scores ( P  < 0.05), the ARAT ( P  < 0.05), and in the MAS ( P  < 0.05) were observed after the training and sustained 3 months later. The EMG parameters indicated a significant decrease of the muscle activation level in flexor digitorum (FD) and biceps brachii ( P  < 0.05), as well as a significant reduction of CIs in the muscle pairs of FD and triceps brachii and biceps brachii and triceps brachii ( P  < 0.05). The upper-limb training integrated with the assistance from the EMG-driven NMES-robotic hand is effective for the improvements of the voluntary motor functions and the muscle coordination in the proximal and distal joints. Furthermore, the motor improvement after the training could be maintained till 3 months later. ClinicalTrials.gov. NCT02117089; date of registration: April

Patterns of cooperation: fairness and coordination in networks of interacting agents

Science.gov (United States)

Do, Anne-Ly; Rudolf, Lars; Gross, Thilo

2010-06-01

We study the self-assembly of a complex network of collaborations among self-interested agents. The agents can maintain different levels of cooperation with different partners. Further, they continuously, selectively and independently adapt the amount of resources allocated to each of their collaborations in order to maximize the obtained payoff. We show analytically that the system approaches a state in which the agents make identical investments, and links produce identical benefits. Despite this high degree of social coordination, some agents manage to secure privileged topological positions in the network, enabling them to extract high payoffs. Our analytical investigations provide a rationale for the emergence of unidirectional non-reciprocal collaborations and different responses to the withdrawal of a partner from an interaction that have been reported in the psychological literature.

Pattern recognition in high energy physics

International Nuclear Information System (INIS)

Tenner, A.G.

1980-01-01

In high energy physics experiments tracks of elementary particles are recorded by different types of equipment. Coordinates of points of these tracks have to be measured for the geometrical reconstruction and the further analysis of the observed events. Pattern recognition methods may facilitate the detection of tracks or whole events and the separation of relevant from non-relevant information. They may also serve for the automation of measurement. Generally, all work is done by digital computation. In a bubble chamber tracks appear as strings of vapour bubbles that can be recorded photographically. Two methods of pattern recognition are discussed. The flying spot digitizer encodes the pattern on the photograph into point coordinates in the memory of a computer. The computer carries out the pattern recognition procedure entirely on the basis of the stored information. Cathode ray instruments scan the photograph by means of a computer steered optical device. Data acquisition from the film is performed in a feedback loop of the computation. In electronic experimental equipment tracks are defined by the spacial distribution of hits of counters (wire counters, scintillation counters, spark chambers). Pattern recognition is generally performed in various stages both by on-line and off-line equipment. Problems in the data handling arise both from the great abundance of data and from the time limits imposed on the on-line computation by high measuring rates. The on-line computation is carried out by hardwired logic, small computers, and to an increasing extent by microprocessors. (Auth.)

Constraint Study for a Hand Exoskeleton: Human Hand Kinematics and Dynamics

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Fai Chen Chen

2013-01-01

Full Text Available In the last few years, the number of projects studying the human hand from the robotic point of view has increased rapidly, due to the growing interest in academic and industrial applications. Nevertheless, the complexity of the human hand given its large number of degrees of freedom (DoF within a significantly reduced space requires an exhaustive analysis, before proposing any applications. The aim of this paper is to provide a complete summary of the kinematic and dynamic characteristics of the human hand as a preliminary step towards the development of hand devices such as prosthetic/robotic hands and exoskeletons imitating the human hand shape and functionality. A collection of data and constraints relevant to hand movements is presented, and the direct and inverse kinematics are solved for all the fingers as well as the dynamics; anthropometric data and dynamics equations allow performing simulations to understand the behavior of the finger.

HandTutor™ enhanced hand rehabilitation after stroke--a pilot study.

Science.gov (United States)

Carmeli, Eli; Peleg, Sara; Bartur, Gadi; Elbo, Enbal; Vatine, Jean-Jacques

2011-12-01

This study assessed the potential therapeutic benefi t of using HandTutor™ in combination with traditional rehabilitation in a post-stroke sub-acute population. The study compares an experimental group receiving traditional therapy combined with HandTutorTM treatment, against a control group receiving only traditional therapy. An assessor-blinded, randomized controlled pilot trial, was conducted in the Reuth rehabilitation unit in Israel. Thirty-one stroke patients in the sub-acute phase, were randomly assigned to one of the two groups (experimental or control) in sets of three. The experimental group (n = 16) underwent a hand rehabilitation programme using the HandTutorTM combined with traditional therapy. The control group (n = 15) received only traditional therapy. The treatment schedules for both groups were of similar duration and frequency. Improvements were evaluated using three indicators: 1) The Brunnström-Fugl-Meyer (FM) test, 2) the Box and Blocks (B&B) test and 3) improvement parameters as determined by the HandTutorTM software. Following 15 consecutive treatment sessions, a signifi cant improvement was observed within the experimental group (95% confi dence intervals) compared with the control group: B&B p = 0.015; FM p = 0.041, HandTutor™ performance accuracy on x axis and performance accuracy on y axis p stroke hand function rehabilitation.

Combinatorial pattern discovery approach for the folding trajectory analysis of a beta-hairpin.

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Laxmi Parida

2005-06-01

Full Text Available The study of protein folding mechanisms continues to be one of the most challenging problems in computational biology. Currently, the protein folding mechanism is often characterized by calculating the free energy landscape versus various reaction coordinates, such as the fraction of native contacts, the radius of gyration, RMSD from the native structure, and so on. In this paper, we present a combinatorial pattern discovery approach toward understanding the global state changes during the folding process. This is a first step toward an unsupervised (and perhaps eventually automated approach toward identification of global states. The approach is based on computing biclusters (or patterned clusters-each cluster is a combination of various reaction coordinates, and its signature pattern facilitates the computation of the Z-score for the cluster. For this discovery process, we present an algorithm of time complexity c in RO((N + nm log n, where N is the size of the output patterns and (n x m is the size of the input with n time frames and m reaction coordinates. To date, this is the best time complexity for this problem. We next apply this to a beta-hairpin folding trajectory and demonstrate that this approach extracts crucial information about protein folding intermediate states and mechanism. We make three observations about the approach: (1 The method recovers states previously obtained by visually analyzing free energy surfaces. (2 It also succeeds in extracting meaningful patterns and structures that had been overlooked in previous works, which provides a better understanding of the folding mechanism of the beta-hairpin. These new patterns also interconnect various states in existing free energy surfaces versus different reaction coordinates. (3 The approach does not require calculating the free energy values, yet it offers an analysis comparable to, and sometimes better than, the methods that use free energy landscapes, thus validating the

Combinatorial Pattern Discovery Approach for the Folding Trajectory Analysis of a beta-Hairpin.

Directory of Open Access Journals (Sweden)

2005-06-01

Full Text Available The study of protein folding mechanisms continues to be one of the most challenging problems in computational biology. Currently, the protein folding mechanism is often characterized by calculating the free energy landscape versus various reaction coordinates, such as the fraction of native contacts, the radius of gyration, RMSD from the native structure, and so on. In this paper, we present a combinatorial pattern discovery approach toward understanding the global state changes during the folding process. This is a first step toward an unsupervised (and perhaps eventually automated approach toward identification of global states. The approach is based on computing biclusters (or patterned clusters-each cluster is a combination of various reaction coordinates, and its signature pattern facilitates the computation of the Z-score for the cluster. For this discovery process, we present an algorithm of time complexity cinRO((N + nm log n, where N is the size of the output patterns and (n x m is the size of the input with n time frames and m reaction coordinates. To date, this is the best time complexity for this problem. We next apply this to a beta-hairpin folding trajectory and demonstrate that this approach extracts crucial information about protein folding intermediate states and mechanism. We make three observations about the approach: (1 The method recovers states previously obtained by visually analyzing free energy surfaces. (2 It also succeeds in extracting meaningful patterns and structures that had been overlooked in previous works, which provides a better understanding of the folding mechanism of the beta-hairpin. These new patterns also interconnect various states in existing free energy surfaces versus different reaction coordinates. (3 The approach does not require calculating the free energy values, yet it offers an analysis comparable to, and sometimes better than, the methods that use free energy landscapes, thus validating the

Setup of a novel biofeedback prototype for sensorimotor control of the hand and preliminary application in patients with peripheral nerve injuries.

Science.gov (United States)

Chiu, Haw-Yen; Hsu, Hsiu-Yun; Su, Fong-Chin; Jou, I-Ming; Lin, Cheng-Feng; Kuo, Li-Chieh

2013-02-01

Biofeedback training is widely used for rehabilitative intervention in patients with central or peripheral nervous impairment to train correct movement patterns; however, no biofeedback apparatus is currently available to correct pinch force ratios for patients with sensory deficiencies. A cross-sectional and longitudinal design was used in an observational measurement study for establishing a prototype and to determine the effects of biofeedback intervention, respectively. This study aimed to develop a computerized evaluation and re-education biofeedback (CERB) prototype for application in clinical settings. A CERB prototype was developed integrating pinch apparatus hardware, a biofeedback user-controlled interface, and a data processing/analysis interface to detect momentary pinch performances in 79 people with normal hand sensation. Nine patients with hand sensory impairments were recruited to investigate the effects of training hand function with the CERB prototype. Hand dominance, pinch pattern, and age significantly affected the peak pinch force and force ratio for lifting a 480-g object with a steel surface. In the case of the 79 volunteers with normal hand sensation, hand dominance affected the time lag between peak pinch force and maximum load; however, it was unaffected by pinch pattern or age. Training with the CERB prototype produced significant improvements in force ratio and better performance in the pin insertion subtests, although the results for both 2-point discriminative and Semmes-Weinstein monofilament tests did not change significantly. The intervention findings are preliminary. This study developed a conjunct system suited for evaluating and restoring sensorimotor function for patients with impaired hand sensibility. The results from the participants with normal hand sensation could serve as a reference database for comparison with patients with nerve injuries.

Synaptic and functional linkages between spinal premotor interneurons and hand-muscle activity during precision grip

Directory of Open Access Journals (Sweden)

Tomohiko eTakei

2013-04-01

Full Text Available Grasping is a highly complex movement that requires the coordination of a number of hand joints and muscles. Previous studies showed that spinal premotor interneurons (PreM-INs in the primate cervical spinal cord have divergent synaptic effects on hand motoneurons and that they might contribute to hand-muscle synergies. However, the extent to which these PreM-IN synaptic connections functionally contribute to modulating hand-muscle activity is not clear. In this paper, we explored the contribution of spinal PreM-INs to hand-muscle activation by quantifying the synaptic linkage (SL and functional linkage (FL of the PreM-INs with hand-muscle activities. The activity of 23 PreM-INs was recorded from the cervical spinal cord (C6–T1, with EMG signals measured simultaneously from hand and arm muscles in two macaque monkeys performing a precision grip task. Spike-triggered averages (STAs of rectified EMGs were compiled for 456 neuron–muscle pairs; 63 pairs showed significant post-spike effects (i.e., SL. Conversely, 231 of 456 pairs showed significant cross-correlations between the IN firing rate and rectified EMG (i.e., FL. Importantly, a greater proportion of the neuron–muscle pairs with SL showed FL (43/63 pairs, 68% compared with the pairs without SL (203/393, 52%, and the presence of SL was significantly associated with that of FL. However, a significant number of pairs had SL without FL (SL∩!FL, n = 20 or FL without SL (!SL∩FL, n = 203, and the proportions of these incongruities exceeded the number expected by chance. These results suggested that spinal PreM-INs function to significantly modulate hand-muscle activity during precision grip, but the contribution of other neural structures is also needed to recruit an adequate combination of hand-muscle motoneurons.

The Avocado Hand

LENUS (Irish Health Repository)

Rahmani, G

2017-11-01

Accidental self-inflicted knife injuries to digits are a common cause of tendon and nerve injury requiring hand surgery. There has been an apparent increase in avocado related hand injuries. Classically, the patients hold the avocado in their non-dominant hand while using a knife to cut\\/peel the fruit with their dominant hand. The mechanism of injury is usually a stabbing injury to the non-dominant hand as the knife slips past the stone, through the soft avocado fruit. Despite their apparent increased incidence, we could not find any cases in the literature which describe the “avocado hand”. We present a case of a 32-year-old woman who sustained a significant hand injury while preparing an avocado. She required exploration and repair of a digital nerve under regional anaesthesia and has since made a full recovery.

Massive coordination of dispersed generation using PowerMatcher based software agents

International Nuclear Information System (INIS)

Kamphuis, I.G.; Hommelberg, M.P.F.; Warmer, C.J.; Kok, J.K.

2007-01-01

well as scalability issues, encountered, are discussed. Further issues covered are the stability of the system as reflected by the internal price development pattern that acts as an 'invisible hand' to reach the common optimisation goal. Finally, the effects of scaling-up the technology are discussed in terms of possible 'emergent behaviour' of subsets in the cluster and primary process quality of appliances operating concertedly using the PowerMatcher

Coordinate measuring machines

DEFF Research Database (Denmark)

De Chiffre, Leonardo

This document is used in connection with three exercises of 2 hours duration as a part of the course GEOMETRICAL METROLOGY AND MACHINE TESTING. The exercises concern three aspects of coordinate measuring: 1) Measuring and verification of tolerances on coordinate measuring machines, 2) Traceabilit...... and uncertainty during coordinate measurements, 3) Digitalisation and Reverse Engineering. This document contains a short description of each step in the exercise and schemes with room for taking notes of the results.......This document is used in connection with three exercises of 2 hours duration as a part of the course GEOMETRICAL METROLOGY AND MACHINE TESTING. The exercises concern three aspects of coordinate measuring: 1) Measuring and verification of tolerances on coordinate measuring machines, 2) Traceability...

Noninvasive brain stimulation for treatment of right- and left-handed poststroke aphasics.

Science.gov (United States)

Heiss, Wolf-Dieter; Hartmann, Alexander; Rubi-Fessen, Ilona; Anglade, Carole; Kracht, Lutz; Kessler, Josef; Weiduschat, Nora; Rommel, Thomas; Thiel, Alexander

2013-01-01

Accumulating evidence from single case studies, small case series and randomized controlled trials seems to suggest that inhibitory noninvasive brain stimulation (NIBS) over the contralesional inferior frontal gyrus (IFG) of right-handers in conjunction with speech and language therapy (SLT) improves recovery from poststroke aphasia. Application of inhibitory NIBS to improve recovery in left-handed patients has not yet been reported. A total of 29 right-handed subacute poststroke aphasics were randomized to receive either 10 sessions of SLT following 20 min of inhibitory repetitive transcranial magnetic stimulation (rTMS) over the contralesional IFG or 10 sessions of SLT following sham stimulation; 2 left-handers were treated according to the same protocol with real rTMS. Language activation patterns were assessed with positron emission tomography prior to and after the treatment; 95% confidence intervals for changes in language performance scores and the activated brain volumes in both hemispheres were derived from TMS- and sham-treated right-handed patients and compared to the same parameters in left-handers. Right-handed patients treated with rTMS showed better recovery of language function in global aphasia test scores (t test, p right-handers. In treated right-handers, a shift of activation to the ipsilesional hemisphere was observed, while sham-treated patients consolidated network activity in the contralesional hemisphere (repeated-measures ANOVA, p = 0.009). Both left-handed patients also improved, with 1 patient within the confidence limits of TMS-treated right-handers (23 points, 15.9-28.9) and the other patient within the limits of sham-treated subjects (8 points, 2.8-14.5). Both patients exhibited only a very small interhemispheric shift, much less than expected in TMS-treated right-handers, and more or less consolidated initially active networks in both hemispheres. Inhibitory rTMS over the nondominant IFG appears to be a safe and effective treatment

Hand and wrist arthritis of Behcet disease: Imaging features

International Nuclear Information System (INIS)

Sugawara, Shunsuke; Ehara, Shigeru; Hitachi, Shin; Sugimoto, Hideharu

2010-01-01

Background: Reports on arthritis in Behcet disease are relatively scarce, and imaging features vary. Purpose: To document the various imaging features of articular disorders of the hand and wrist in Behcet disease. Material and Methods: Four patients, four women aged 26 to 65 years, fulfilling the diagnostic criteria of Behcet disease, with imaging findings of hand and wrist arthritis, were seen in two institutions. Radiography and magnetic resonance (MR) imaging were studied to elucidate the pattern and distribution. Results: Both non-erosive arthritis and erosive arthritis of different features were noted: one with non-erosive synovitis of the wrist, one with wrist synovitis with minimal erosion, and two with erosive arthritis of the distal interphalangeal joint. Conclusion: Imaging manifestations of arthritis of Behcet disease vary, and may be similar to other seronegative arthritides

Generating spatiotemporal joint torque patterns from dynamical synchronization of distributed pattern generators

Directory of Open Access Journals (Sweden)

Alex Pitti

2009-10-01

Full Text Available Pattern generators found in the spinal cords are no more seen as simple rhythmic oscillators for motion control. Indeed, they achieve flexible and dynamical coordination in interaction with the body and the environment dynamics to rise motor synergies. Discovering the mechanisms underlying the control of motor synergies constitute an important research question not only for neuroscience but also for robotics: the motors coordination of high dimensional robotic systems is still a drawback and new control methods based on biological solutions may reduce their overall complexity. We propose to model the flexible combination of motor synergies in embodied systems via partial phase synchronization of distributed chaotic systems; for specific coupling strength, chaotic systems are able to phase synchronize their dynamics to the resonant frequencies of one external force. We take advantage of this property to explore and exploit the intrinsic dynamics of one specified embodied system. In two experiments with bipedal walkers, we show how motor synergies emerge when the controllers phase synchronize to the body’s dynamics, entraining it to its intrinsic behavioral patterns. This stage is characterized by directed information flow from the sensors to the motors exhibiting the optimal situation when the body dynamics drive the controllers (mutual entrainment. Based on our results, we discuss the relevance of our findings for modeling the modular control of distributed pattern generators exhibited in the spinal cords, and for exploring the motor synergies in robots.

Ability of Hand Hygiene Interventions Using Alcohol-Based Hand Sanitizers and Soap To Reduce Microbial Load on Farmworker Hands Soiled during Harvest.

Science.gov (United States)

de Aceituno, Anna Fabiszewski; Bartz, Faith E; Hodge, Domonique Watson; Shumaker, David J; Grubb, James E; Arbogast, James W; Dávila-Aviña, Jorgé; Venegas, Fabiola; Heredia, Norma; García, Santos; Leon, Juan S

2015-11-01

Effective hand hygiene is essential to prevent the spread of pathogens on produce farms and reduce foodborne illness. The U.S. Food and Drug Administration Food Safety Modernization Act Proposed Rule for Produce Safety recommends the use of soap and running water for hand hygiene of produce handlers. The use of alcohol-based hand sanitizer (ABHS) may be an effective alternative hygiene intervention where access to water is limited. There are no published data on the efficacy of either soap or ABHS-based interventions to reduce microbial contamination in agricultural settings. The goal of this study was to assess the ability of two soap-based (traditional or pumice) and two ABHS-based (label-use or two-step) hygiene interventions to reduce microbes (coliforms, Escherichia coli, and Enterococcus spp.) and soil (absorbance of hand rinsate at 600 nm [A600]) on farmworker hands after harvesting produce, compared with the results for a no-hand-hygiene control. With no hand hygiene, farmworker hands were soiled (median A600, 0.48) and had high concentrations of coliforms (geometric mean, 3.4 log CFU per hand) and Enterococcus spp. (geometric mean, 5.3 log CFU per hand) after 1 to 2 h of harvesting tomatoes. Differences in microbial loads in comparison to the loads in the control group varied by indicator organism and hygiene intervention (0 to 2.3 log CFU per hand). All interventions yielded lower concentrations of Enterococcus spp. and E. coli (P hands (P hand washing with soap at reducing indicator organisms on farmworker hands. Based on these results, ABHS is an efficacious hand hygiene solution for produce handlers, even on soiled hands.

Hand Therapy

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... from conditions such as carpal tunnel syndrome and tennis elbow , as well as from chronic problems such as ... Tools Advice from a Certified Hand Therapist on Tennis Elbow Advice from a Certified Hand Therapist: Living with( ...