Anthropomorphic Robot Hand And Teaching Glove

NASA Technical Reports Server (NTRS)

Engler, Charles D., Jr.

1991-01-01

Robotic forearm-and-hand assembly manipulates objects by performing wrist and hand motions with nearly human grasping ability and dexterity. Imitates hand motions of human operator who controls robot in real time by programming via exoskeletal "teaching glove". Telemanipulator systems based on this robotic-hand concept useful where humanlike dexterity required. Underwater, high-radiation, vacuum, hot, cold, toxic, or inhospitable environments potential application sites. Particularly suited to assisting astronauts on space station in safely executing unexpected tasks requiring greater dexterity than standard gripper.

Dexterous programmable robot and control system

NASA Astrophysics Data System (ADS)

Engler, Charles D., Jr.

1995-09-01

An anatomically correct, humanlike, mechanical arm and hand is provided that an operator can control to perform with the dexterity and compliance of a human hand. Being humanlike and robotic enhances the device's control and gripper dexterity. Control of the movement of the arm and hand is performed or guided by a 'teach glove' worn by the operator. As he or she performs some hand manipulation, a controller stores signals from sensors on the exoskeleton. The sensors monitor the operator's finger-joint movement positions. These values are later translated into actuator control signals for servomotors, eventually duplicating the operator's movement.

A new approach of active compliance control via fuzzy logic control for multifingered robot hand

NASA Astrophysics Data System (ADS)

Jamil, M. F. A.; Jalani, J.; Ahmad, A.

2016-07-01

Safety is a vital issue in Human-Robot Interaction (HRI). In order to guarantee safety in HRI, a model reference impedance control can be a very useful approach introducing a compliant control. In particular, this paper establishes a fuzzy logic compliance control (i.e. active compliance control) to reduce impact and forces during physical interaction between humans/objects and robots. Exploiting a virtual mass-spring-damper system allows us to determine a desired compliant level by understanding the behavior of the model reference impedance control. The performance of fuzzy logic compliant control is tested in simulation for a robotic hand known as the RED Hand. The results show that the fuzzy logic is a feasible control approach, particularly to control position and to provide compliant control. In addition, the fuzzy logic control allows us to simplify the controller design process (i.e. avoid complex computation) when dealing with nonlinearities and uncertainties.

Hand controller commonality evaluation process

NASA Technical Reports Server (NTRS)

Stuart, Mark A.; Bierschwale, John M.; Wilmington, Robert P.; Adam, Susan C.; Diaz, Manuel F.; Jensen, Dean G.

1993-01-01

Hand controller selection for NASA's Orbiter and Space Station Freedom is an important area of human-telerobot interface design and evaluation. These input devices will control remotely operated systems that include large crane-like manipulators (e.g., Remote Manipulator System or RMS), smaller, more dexterous manipulators (e.g., Flight Telerobotic Servicer or FTS), and free flyers (e.g., Orbital Maneuvering Vehicle or OMV). Candidate hand controller configurations for these systems vary in many ways: shape, size, number of degrees-of-freedom (DOF), operating modes, provision of force reflection, range of movement, and 'naturalness' of use. Unresolved design implementation issues remain, including such topics as how the current Orbiter RMS rotational and translational rate hand controllers compare with the proposed Space Station Freedom hand controllers, the advantages that position hand controllers offer for these applications, and whether separate hand controller configurations are required for each application. Since previous studies contain little empirical hand controller task performance data, a controlled study is needed that tests Space Station Freedom candidate hand controllers during representative tasks. This study also needs to include anthropometric and biomechanical considerations.

Adapting proportional myoelectric-controlled interfaces for prosthetic hands.

PubMed

Pistohl, Tobias; Cipriani, Christian; Jackson, Andrew; Nazarpour, Kianoush

2013-01-01

Powered hand prostheses with many degrees of freedom are moving from research into the market for prosthetics. In order to make use of the prostheses' full functionality, it is essential to find efficient ways to control their multiple actuators. Human subjects can rapidly learn to employ electromyographic (EMG) activity of several hand and arm muscles to control the position of a cursor on a computer screen, even if the muscle-cursor map contradicts directions in which the muscles would act naturally. We investigated whether a similar control scheme, using signals from four hand muscles, could be adopted for real-time operation of a dexterous robotic hand. Despite different mapping strategies, learning to control the robotic hand over time was surprisingly similar to the learning of two-dimensional cursor control.

Improving Fine Control of Grasping Force during Hand–Object Interactions for a Soft Synergy-Inspired Myoelectric Prosthetic Hand

PubMed Central

Fu, Qiushi; Santello, Marco

2018-01-01

The concept of postural synergies of the human hand has been shown to potentially reduce complexity in the neuromuscular control of grasping. By merging this concept with soft robotics approaches, a multi degrees of freedom soft-synergy prosthetic hand [SoftHand-Pro (SHP)] was created. The mechanical innovation of the SHP enables adaptive and robust functional grasps with simple and intuitive myoelectric control from only two surface electromyogram (sEMG) channels. However, the current myoelectric controller has very limited capability for fine control of grasp forces. We addressed this challenge by designing a hybrid-gain myoelectric controller that switches control gains based on the sensorimotor state of the SHP. This controller was tested against a conventional single-gain (SG) controller, as well as against native hand in able-bodied subjects. We used the following tasks to evaluate the performance of grasp force control: (1) pick and place objects with different size, weight, and fragility levels using power or precision grasp and (2) squeezing objects with different stiffness. Sensory feedback of the grasp forces was provided to the user through a non-invasive, mechanotactile haptic feedback device mounted on the upper arm. We demonstrated that the novel hybrid controller enabled superior task completion speed and fine force control over SG controller in object pick-and-place tasks. We also found that the performance of the hybrid controller qualitatively agrees with the performance of native human hands. PMID:29375360

The SmartHand transradial prosthesis

PubMed Central

2011-01-01

Background Prosthetic components and control interfaces for upper limb amputees have barely changed in the past 40 years. Many transradial prostheses have been developed in the past, nonetheless most of them would be inappropriate if/when a large bandwidth human-machine interface for control and perception would be available, due to either their limited (or inexistent) sensorization or limited dexterity. SmartHand tackles this issue as is meant to be clinically experimented in amputees employing different neuro-interfaces, in order to investigate their effectiveness. This paper presents the design and on bench evaluation of the SmartHand. Methods SmartHand design was bio-inspired in terms of its physical appearance, kinematics, sensorization, and its multilevel control system. Underactuated fingers and differential mechanisms were designed and exploited in order to fit all mechatronic components in the size and weight of a natural human hand. Its sensory system was designed with the aim of delivering significant afferent information to the user through adequate interfaces. Results SmartHand is a five fingered self-contained robotic hand, with 16 degrees of freedom, actuated by 4 motors. It integrates a bio-inspired sensory system composed of 40 proprioceptive and exteroceptive sensors and a customized embedded controller both employed for implementing automatic grasp control and for potentially delivering sensory feedback to the amputee. It is able to perform everyday grasps, count and independently point the index. The weight (530 g) and speed (closing time: 1.5 seconds) are comparable to actual commercial prostheses. It is able to lift a 10 kg suitcase; slippage tests showed that within particular friction and geometric conditions the hand is able to stably grasp up to 3.6 kg cylindrical objects. Conclusions Due to its unique embedded features and human-size, the SmartHand holds the promise to be experimentally fitted on transradial amputees and employed as a bi-directional instrument for investigating -during realistic experiments- different interfaces, control and feedback strategies in neuro-engineering studies. PMID:21600048

The Robonaut 2 Hand - Designed to do Work with Tools

NASA Technical Reports Server (NTRS)

Bridgwater, L. B.; Ihrke, C. A.; Diftler, M. A.; Abdallah, M. E.; Radford, N. A.; Rogers, J. M.; Yayathi, S.; Askew, R. S.; Linn, D. M.

2011-01-01

The second generation Robonaut hand has many advantages over its predecessor. This mechatronic device is more dexterous and has improved force control and sensing giving it the capability to grasp and actuate a wider range of tools. It can achieve higher peak forces at higher speeds than the original. Developed as part of a partnership between General Motors and NASA, the hand is designed to more closely approximate a human hand. Having a more anthropomorphic design allows the hand to attain a larger set of useful grasps for working with human interfaces. Key to the hand s improved performance is the use of lower friction drive elements and a redistribution of components from the hand to the forearm, permitting more sensing in the fingers and palm where it is most important. The following describes the design, mechanical/electrical integration, and control features of the hand. Lessons learned during the development and initial operations along with planned refinements to make it more effective are presented.

Multi-finger prehension: control of a redundant mechanical system.

PubMed

Latash, Mark L; Zatsiorsky, Vladimir M

2009-01-01

The human hand has been a fascinating object of study for researchers in both biomechanics and motor control. Studies of human prehension have contributed significantly to the progress in addressing the famous problem of motor redundancy. After a brief review of the hand mechanics, we present results of recent studies that support a general view that the apparently redundant design of the hand is not a source of computational problems but a rich apparatus that allows performing a variety of tasks in a reliable and flexible way (the principle of abundance). Multi-digit synergies have been analyzed at two levels of a hypothetical hierarchy involved in the control of prehensile actions. At the upper level, forces and moments produced by the thumb and virtual finger (an imagined finger with a mechanical action equal to the combined mechanical action of all four fingers of the hand) co-vary to stabilize the gripping action and the orientation of the hand-held object. These results support the principle of superposition suggested earlier in robotics with respect to the control of artificial grippers. At the lower level of the hierarchy, forces and moments produced by individual fingers co-vary to stabilize the magnitude and direction of the force vector and the moment of force produced by the virtual finger. Adjustments to changes in task constraints (such as, for example, friction under individual digits) may be local and synergic. The latter reflect multi-digit prehension synergies and may be analyzed with the so-called chain effects: Sequences of relatively straightforward cause-effect links directly related to mechanical constraints leading to non-trivial strong co-variation between pairs of elemental variables. Analysis of grip force adjustments during motion of hand-held objects suggests that the central nervous system adjusts to gravitational and inertial loads differently. The human hand is a gold mine for researchers interested in the control of natural human movements.

The Hand: Shall We Ever Understand How it Works?

PubMed

Latash, Mark L

2015-04-01

The target article presents a review of the neural control of the human hand. The review emphasizes the physical approach to motor control. It focuses on such concepts as equilibrium-point control, control with referent body configurations, uncontrolled manifold hypothesis, principle of abundance, hierarchical control, multidigit synergies, and anticipatory synergy adjustments. Changes in aspects of the hand neural control with age and neurological disorder are discussed. The target article is followed by six commentaries written by Alexander Aruin, Kelly Cole, Monica Perez, Robert Sainburg, Marco Sanello, and Wei Zhang.

Uncontrolled Manifold Reference Feedback Control of Multi-Joint Robot Arms

PubMed Central

Togo, Shunta; Kagawa, Takahiro; Uno, Yoji

2016-01-01

The brain must coordinate with redundant bodies to perform motion tasks. The aim of the present study is to propose a novel control model that predicts the characteristics of human joint coordination at a behavioral level. To evaluate the joint coordination, an uncontrolled manifold (UCM) analysis that focuses on the trial-to-trial variance of joints has been proposed. The UCM is a nonlinear manifold associated with redundant kinematics. In this study, we directly applied the notion of the UCM to our proposed control model called the “UCM reference feedback control.” To simplify the problem, the present study considered how the redundant joints were controlled to regulate a given target hand position. We considered a conventional method that pre-determined a unique target joint trajectory by inverse kinematics or any other optimization method. In contrast, our proposed control method generates a UCM as a control target at each time step. The target UCM is a subspace of joint angles whose variability does not affect the hand position. The joint combination in the target UCM is then selected so as to minimize the cost function, which consisted of the joint torque and torque change. To examine whether the proposed method could reproduce human-like joint coordination, we conducted simulation and measurement experiments. In the simulation experiments, a three-link arm with a shoulder, elbow, and wrist regulates a one-dimensional target of a hand through proposed method. In the measurement experiments, subjects performed a one-dimensional target-tracking task. The kinematics, dynamics, and joint coordination were quantitatively compared with the simulation data of the proposed method. As a result, the UCM reference feedback control could quantitatively reproduce the difference of the mean value for the end hand position between the initial postures, the peaks of the bell-shape tangential hand velocity, the sum of the squared torque, the mean value for the torque change, the variance components, and the index of synergy as well as the human subjects. We concluded that UCM reference feedback control can reproduce human-like joint coordination. The inference for motor control of the human central nervous system based on the proposed method was discussed. PMID:27462215

The effects of voice and manual control mode on dual task performance

NASA Technical Reports Server (NTRS)

Wickens, C. D.; Zenyuh, J.; Culp, V.; Marshak, W.

1986-01-01

Two fundamental principles of human performance, compatibility and resource competition, are combined with two structural dichotomies in the human information processing system, manual versus voice output, and left versus right cerebral hemisphere, in order to predict the optimum combination of voice and manual control with either hand, for time-sharing performance of a dicrete and continuous task. Eight right handed male subjected performed a discrete first-order tracking task, time-shared with an auditorily presented Sternberg Memory Search Task. Each task could be controlled by voice, or by the left or right hand, in all possible combinations except for a dual voice mode. When performance was analyzed in terms of a dual-task decrement from single task control conditions, the following variables influenced time-sharing efficiency in diminishing order of magnitude, (1) the modality of control, (discrete manual control of tracking was superior to discrete voice control of tracking and the converse was true with the memory search task), (2) response competition, (performance was degraded when both tasks were responded manually), (3) hemispheric competition, (performance degraded whenever two tasks were controlled by the left hemisphere) (i.e., voice or right handed control). The results confirm the value of predictive models invoice control implementation.

Performance evaluation of haptic hand-controllers in a robot-assisted surgical system.

PubMed

Zareinia, Kourosh; Maddahi, Yaser; Ng, Canaan; Sepehri, Nariman; Sutherland, Garnette R

2015-12-01

This paper presents the experimental evaluation of three commercially available haptic hand-controllers to evaluate which was more suitable to the participants. Two surgeons and seven engineers performed two peg-in-hole tasks with different levels of difficulty. Each operator guided the end-effector of a Kuka manipulator that held surgical forceps and was equipped with a surgical microscope. Sigma 7, HD(2) and PHANToM Premium 3.0 hand-controllers were compared. Ten measures were adopted to evaluate operators' performances with respect to effort, speed and accuracy in completing a task, operator improvement during the tests, and the force applied by each haptic device. The best performance was observed with the Premium 3.0; the hand-piece was able to be held in a similar way to that used by surgeons to hold conventional tools. Hand-controllers with a linkage structure similar to the human upper extremity take advantage of the inherent human brain connectome, resulting in improved surgeon performance during robotic-assisted surgery. Copyright © 2015 John Wiley & Sons, Ltd.

Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands

PubMed Central

Santello, Marco; Bianchi, Matteo; Gabiccini, Marco; Ricciardi, Emiliano; Salvietti, Gionata; Prattichizzo, Domenico; Ernst, Marc; Moscatelli, Alessandro; Jörntell, Henrik; Kappers, Astrid M.L.; Kyriakopoulos, Kostas; Albu-Schäffer, Alin; Castellini, Claudio; Bicchi, Antonio

2017-01-01

The term ‘synergy’ – from the Greek synergia – means ‘working together’. The concept of multiple elements working together towards a common goal has been extensively used in neuroscience to develop theoretical frameworks, experimental approaches, and analytical techniques to understand neural control of movement, and for applications for neuro-rehabilitation. In the past decade, roboticists have successfully applied the framework of synergies to create novel design and control concepts for artificial hands, i.e., robotic hands and prostheses. At the same time, robotic research on the sensorimotor integration underlying the control and sensing of artificial hands has inspired new research approaches in neuroscience, and has provided useful instruments for novel experiments. The ambitious goal of integrating expertise and research approaches in robotics and neuroscience to study the properties and applications of the concept of synergies is generating a number of multidisciplinary cooperative projects, among which the recently finished 4-year European project “The Hand Embodied” (THE). This paper reviews the main insights provided by this framework. Specifically, we provide an overview of neuroscientific bases of hand synergies and introduce how robotics has leveraged the insights from neuroscience for innovative design in hardware and controllers for biomedical engineering applications, including myoelectric hand prostheses, devices for haptics research, and wearable sensing of human hand kinematics. The review also emphasizes how this multidisciplinary collaboration has generated new ways to conceptualize a synergy-based approach for robotics, and provides guidelines and principles for analyzing human behavior and synthesizing artificial robotic systems based on a theory of synergies. PMID:26923030

Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands.

PubMed

Santello, Marco; Bianchi, Matteo; Gabiccini, Marco; Ricciardi, Emiliano; Salvietti, Gionata; Prattichizzo, Domenico; Ernst, Marc; Moscatelli, Alessandro; Jörntell, Henrik; Kappers, Astrid M L; Kyriakopoulos, Kostas; Albu-Schäffer, Alin; Castellini, Claudio; Bicchi, Antonio

2016-07-01

The term 'synergy' - from the Greek synergia - means 'working together'. The concept of multiple elements working together towards a common goal has been extensively used in neuroscience to develop theoretical frameworks, experimental approaches, and analytical techniques to understand neural control of movement, and for applications for neuro-rehabilitation. In the past decade, roboticists have successfully applied the framework of synergies to create novel design and control concepts for artificial hands, i.e., robotic hands and prostheses. At the same time, robotic research on the sensorimotor integration underlying the control and sensing of artificial hands has inspired new research approaches in neuroscience, and has provided useful instruments for novel experiments. The ambitious goal of integrating expertise and research approaches in robotics and neuroscience to study the properties and applications of the concept of synergies is generating a number of multidisciplinary cooperative projects, among which the recently finished 4-year European project "The Hand Embodied" (THE). This paper reviews the main insights provided by this framework. Specifically, we provide an overview of neuroscientific bases of hand synergies and introduce how robotics has leveraged the insights from neuroscience for innovative design in hardware and controllers for biomedical engineering applications, including myoelectric hand prostheses, devices for haptics research, and wearable sensing of human hand kinematics. The review also emphasizes how this multidisciplinary collaboration has generated new ways to conceptualize a synergy-based approach for robotics, and provides guidelines and principles for analyzing human behavior and synthesizing artificial robotic systems based on a theory of synergies. Copyright © 2016 Elsevier B.V. All rights reserved.

Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands

NASA Astrophysics Data System (ADS)

Santello, Marco; Bianchi, Matteo; Gabiccini, Marco; Ricciardi, Emiliano; Salvietti, Gionata; Prattichizzo, Domenico; Ernst, Marc; Moscatelli, Alessandro; Jörntell, Henrik; Kappers, Astrid M. L.; Kyriakopoulos, Kostas; Albu-Schäffer, Alin; Castellini, Claudio; Bicchi, Antonio

2016-07-01

The term 'synergy' - from the Greek synergia - means 'working together'. The concept of multiple elements working together towards a common goal has been extensively used in neuroscience to develop theoretical frameworks, experimental approaches, and analytical techniques to understand neural control of movement, and for applications for neuro-rehabilitation. In the past decade, roboticists have successfully applied the framework of synergies to create novel design and control concepts for artificial hands, i.e., robotic hands and prostheses. At the same time, robotic research on the sensorimotor integration underlying the control and sensing of artificial hands has inspired new research approaches in neuroscience, and has provided useful instruments for novel experiments. The ambitious goal of integrating expertise and research approaches in robotics and neuroscience to study the properties and applications of the concept of synergies is generating a number of multidisciplinary cooperative projects, among which the recently finished 4-year European project ;The Hand Embodied; (THE). This paper reviews the main insights provided by this framework. Specifically, we provide an overview of neuroscientific bases of hand synergies and introduce how robotics has leveraged the insights from neuroscience for innovative design in hardware and controllers for biomedical engineering applications, including myoelectric hand prostheses, devices for haptics research, and wearable sensing of human hand kinematics. The review also emphasizes how this multidisciplinary collaboration has generated new ways to conceptualize a synergy-based approach for robotics, and provides guidelines and principles for analyzing human behavior and synthesizing artificial robotic systems based on a theory of synergies.

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

PubMed

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.

Compensatory changes accompanying chronic forced use of the nondominant hand by unilateral amputees.

PubMed

Philip, Benjamin A; Frey, Scott H

2014-03-05

Amputation of the dominant hand forces patients to use the nondominant hand exclusively, including for tasks (e.g., writing and drawing) that were formerly the sole domain of the dominant hand. The behavioral and neurological effects of this chronic forced use of the nondominant hand remain largely unknown. Yet, these effects may shed light on the potential to compensate for degradation or loss of dominant hand function, as well as the mechanisms that support motor learning under conditions of very long-term training. We used a novel precision drawing task and fMRI to investigate 8 adult human amputees with chronic (mean 33 years) unilateral dominant (right) hand absence, and right-handed matched controls (8 for fMRI, 19 for behavior). Amputees' precision drawing performances with their left hands reached levels of smoothness (associated with left hemisphere control), acceleration time (associated with right hemisphere control), and speed equivalent to controls' right hands, whereas accuracy maintained a level comparable with controls' left hands. This compensation is supported by an experience-dependent shift from heavy reliance on the dorsodorsal parietofrontal pathway (feedback control) to the ventrodorsal pathway and prefrontal regions involved in the cognitive control of goal-directed actions. Relative to controls, amputees also showed increased activity within the former cortical sensorimotor hand territory in the left (ipsilateral) hemisphere. These data demonstrate that, with chronic and exclusive forced use, the speed and quality of nondominant hand precision endpoint control in drawing can achieve levels nearly comparable with the dominant hand.

Tool making, hand morphology and fossil hominins.

PubMed

Marzke, Mary W

2013-11-19

Was stone tool making a factor in the evolution of human hand morphology? Is it possible to find evidence in fossil hominin hands for this capability? These questions are being addressed with increasingly sophisticated studies that are testing two hypotheses; (i) that humans have unique patterns of grip and hand movement capabilities compatible with effective stone tool making and use of the tools and, if this is the case, (ii) that there exist unique patterns of morphology in human hands that are consistent with these capabilities. Comparative analyses of human stone tool behaviours and chimpanzee feeding behaviours have revealed a distinctive set of forceful pinch grips by humans that are effective in the control of stones by one hand during manufacture and use of the tools. Comparative dissections, kinematic analyses and biomechanical studies indicate that humans do have a unique pattern of muscle architecture and joint surface form and functions consistent with the derived capabilities. A major remaining challenge is to identify skeletal features that reflect the full morphological pattern, and therefore may serve as clues to fossil hominin manipulative capabilities. Hominin fossils are evaluated for evidence of patterns of derived human grip and stress-accommodation features.

Tool making, hand morphology and fossil hominins

PubMed Central

Marzke, Mary W.

2013-01-01

Was stone tool making a factor in the evolution of human hand morphology? Is it possible to find evidence in fossil hominin hands for this capability? These questions are being addressed with increasingly sophisticated studies that are testing two hypotheses; (i) that humans have unique patterns of grip and hand movement capabilities compatible with effective stone tool making and use of the tools and, if this is the case, (ii) that there exist unique patterns of morphology in human hands that are consistent with these capabilities. Comparative analyses of human stone tool behaviours and chimpanzee feeding behaviours have revealed a distinctive set of forceful pinch grips by humans that are effective in the control of stones by one hand during manufacture and use of the tools. Comparative dissections, kinematic analyses and biomechanical studies indicate that humans do have a unique pattern of muscle architecture and joint surface form and functions consistent with the derived capabilities. A major remaining challenge is to identify skeletal features that reflect the full morphological pattern, and therefore may serve as clues to fossil hominin manipulative capabilities. Hominin fossils are evaluated for evidence of patterns of derived human grip and stress-accommodation features. PMID:24101624

The Control of Behavior: Human and Environmental

ERIC Educational Resources Information Center

Burhoe, Ralph Wendell

1972-01-01

Theological perspective on human and environmental behavior, with a view toward man's ultimate concerns or longest range values and the ultimate controls of behavior. Maintains that all human behavior and destiny is ultimately in the hand of a transcendent power which prevails over any human errors.'' (LK)

To react or not to react? Intrinsic stochasticity of human control in virtual stick balancing

PubMed Central

Zgonnikov, Arkady; Lubashevsky, Ihor; Kanemoto, Shigeru; Miyazawa, Toru; Suzuki, Takashi

2014-01-01

Understanding how humans control unstable systems is central to many research problems, with applications ranging from quiet standing to aircraft landing. Increasingly, much evidence appears in favour of event-driven control hypothesis: human operators only start actively controlling the system when the discrepancy between the current and desired system states becomes large enough. The event-driven models based on the concept of threshold can explain many features of the experimentally observed dynamics. However, much still remains unclear about the dynamics of human-controlled systems, which likely indicates that humans use more intricate control mechanisms. This paper argues that control activation in humans may be not threshold-driven, but instead intrinsically stochastic, noise-driven. Specifically, we suggest that control activation stems from stochastic interplay between the operator's need to keep the controlled system near the goal state, on the one hand, and the tendency to postpone interrupting the system dynamics, on the other hand. We propose a model capturing this interplay and show that it matches the experimental data on human balancing of virtual overdamped stick. Our results illuminate that the noise-driven activation mechanism plays a crucial role at least in the considered task, and, hypothetically, in a broad range of human-controlled processes. PMID:25056217

The Effect of Part-simulation of Weightlessness on Human Control of Bilateral Teleoperation: Neuromotor Considerations

NASA Technical Reports Server (NTRS)

Corker, K.; Bejczy, A. K.

1984-01-01

The effect of weightlessness on the human operator's performance in force reflecting position control of remote manipulators was investigated. A gravity compensation system was developed to simulate the effect of weightlessness on the operator's arm. A universal force reflecting hand controller (FRHC) and task simulation software were employed. Two experiments were performed because of anticipated disturbances in neuromotor control specification on the human operator in an orbital control environment to investigate: (1) the effect of controller stiffness on the attainment of a learned terminal position in the three dimensional controller space, and (2) the effect of controller stiffness and damping on force tracking of the contour of a simulated three dimensional cube using the part simulation of weightless conditions. The results support the extension of neuromotor control models, which postulate a stiffness balance encoding of terminal position, to three dimensional motion of a multilink system, confirm the existence of a disturbance in human manual control performance under gravity compensated conditions, and suggest techniques for compensation of weightlessness induced performance decrement through appropriate specification of hand controller response characteristics. These techniques are based on the human control model.

Kinematics and force analysis of a robot hand based on an artificial biological control scheme

NASA Astrophysics Data System (ADS)

Kim, Man Guen

An artificial biological control scheme (ABCS) is used to study the kinematics and statics of a multifingered hand with a view to developing an efficient control scheme for grasping. The ABCS is based on observation of human grasping, intuitively taking it as the optimum model for robotic grasping. A final chapter proposes several grasping measures to be applied to the design and control of a robot hand. The ABCS leads to the definition of two modes of the grasping action: natural grasping (NG), which is the human motion to grasp the object without any special task command, and forced grasping (FG), which is the motion with a specific task. The grasping direction line (GDL) is defined to determine the position and orientation of the object in the hand. The kinematic model of a redundant robot arm and hand is developed by reconstructing the human upper extremity and using anthropometric measurement data. The inverse kinematic analyses of various types of precision and power grasping are studied by replacing the three-link with one virtual link and using the GDL. The static force analysis for grasping with fingertips is studied by applying the ABCS. A measure of grasping stability, that maintains the positions of contacts as well as the configurations of the redundant fingers, is derived. The grasping stability measure (GSM), a measure of how well the hand maintains grasping under the existence of external disturbance, is derived by the torque vector of the hand calculated from the external force applied to the object. The grasping manipulability measure (GMM), a measure of how well the hand manipulates the object for the task, is derived by the joint velocity vector of the hand calculated from the object velocity. The grasping performance measure (GPM) is defined by the sum of the directional components of the GSM and the GMM. Finally, a planar redundant hand with two fingers is examined in order to study the various postures of the hand performing pinch grasping by applying the GSM and the GMM.

Augmented robotic device for EVA hand manoeuvres

NASA Astrophysics Data System (ADS)

Matheson, Eloise; Brooker, Graham

2012-12-01

During extravehicular activities (EVAs), pressurised space suits can lead to difficulties in performing hand manoeuvres and fatigue. This is often the cause of EVAs being terminated early, or taking longer to complete. Assistive robotic gloves can be used to augment the natural motion of a human hand, meaning work can be carried out more efficiently with less stress to the astronaut. Lightweight and low profile solutions must be found in order for the assistive robotic glove to be easily integrated with a space suit pressure garment. Pneumatic muscle actuators combined with force sensors are one such solution. These actuators are extremely light, yet can output high forces using pressurised gases as the actuation drive. Their movement is omnidirectional, so when combined with a flexible exoskeleton that itself provides a degree of freedom of movement, individual fingers can be controlled during flexion and extension. This setup allows actuators and other hardware to be stored remotely on the user's body, resulting in the least possible mass being supported by the hand. Two prototype gloves have been developed at the University of Sydney; prototype I using a fibreglass exoskeleton to provide flexion force, and prototype II using torsion springs to achieve the same result. The gloves have been designed to increase the ease of human movements, rather than to add unnatural ability to the hand. A state space control algorithm has been developed to ensure that human initiated movements are recognised, and calibration methods have been implemented to accommodate the different characteristics of each wearer's hands. For this calibration technique, it was necessary to take into account the natural tremors of the human hand which may have otherwise initiated unexpected control signals. Prototype I was able to actuate the user's hand in 1 degree of freedom (DOF) from full flexion to partial extension, and prototype II actuated a user's finger in 2 DOF with forces achieved comparable to those of a natural, healthy hand. The minimum mass held by the user on the hand was 240 g, with remote hardware, including a compressed air bottle, having a further mass of 1.6 kg. These results indicate that the design is able to augment human motion in a low profile, low mass package, and could be a valuable addition to a space suit during an EVA.

Surface EMG in advanced hand prosthetics.

PubMed

Castellini, Claudio; van der Smagt, Patrick

2009-01-01

One of the major problems when dealing with highly dexterous, active hand prostheses is their control by the patient wearing them. With the advances in mechatronics, building prosthetic hands with multiple active degrees of freedom is realisable, but actively controlling the position and especially the exerted force of each finger cannot yet be done naturally. This paper deals with advanced robotic hand control via surface electromyography. Building upon recent results, we show that machine learning, together with a simple downsampling algorithm, can be effectively used to control on-line, in real time, finger position as well as finger force of a highly dexterous robotic hand. The system determines the type of grasp a human subject is willing to use, and the required amount of force involved, with a high degree of accuracy. This represents a remarkable improvement with respect to the state-of-the-art of feed-forward control of dexterous mechanical hands, and opens up a scenario in which amputees will be able to control hand prostheses in a much finer way than it has so far been possible.

Cyber integrated MEMS microhand for biological applications

NASA Astrophysics Data System (ADS)

Weissman, Adam; Frazier, Athena; Pepen, Michael; Lu, Yen-Wen; Yang, Shanchieh Jay

2009-05-01

Anthropomorphous robotic hands at microscales have been developed to receive information and perform tasks for biological applications. To emulate a human hand's dexterity, the microhand requires a master-slave interface with a wearable controller, force sensors, and perception displays for tele-manipulation. Recognizing the constraints and complexity imposed in developing feedback interface during miniaturization, this project address the need by creating an integrated cyber environment incorporating sensors with a microhand, haptic/visual display, and object model, to emulates human hands' psychophysical perception at microscale.

Telepresence master glove controller for dexterous robotic end-effectors

NASA Technical Reports Server (NTRS)

Fisher, Scott S.

1987-01-01

This paper describes recent research in the Aerospace Human Factors Research Division at NASA's Ames Research Center to develop a glove-like, control and data-recording device (DataGlove) that records and transmits to a host computer in real time, and at appropriate resolution, a numeric data-record of a user's hand/finger shape and dynamics. System configuration and performance specifications are detailed, and current research is discussed investigating its applications in operator control of dexterous robotic end-effectors and for use as a human factors research tool in evaluation of operator hand function requirements and performance in other specialized task environments.

Single treatment with ethanol hand rub is ineffective against human rhinovirus--hand washing with soap and water removes the virus efficiently.

PubMed

Savolainen-Kopra, Carita; Korpela, Terttu; Simonen-Tikka, Marja-Leena; Amiryousefi, Ali; Ziegler, Thedi; Roivainen, Merja; Hovi, Tapani

2012-03-01

Ethanol-containing hand rubs are used frequently as a substitute for hand washing with water and soap. However, not all viruses are inactivated by a short term rubbing with alcohol. The capacity of a single round of instructed and controlled hand cleaning with water and soap or ethanol-containing hand rub, respectively, was tested for removal of human rhinovirus administered onto the skin of healthy volunteers on the back of the hands. Hand washing with soap and water appeared to be much more efficient for removing rhinoviruses from skin than rubbing hands with an ethanol-containing disinfectant. After washing with soap and water the virus was detected in 3/9 (33.3%) test persons from the left hand and 1/9 (11.1%) cases from the right hand, whereas the virus was detected invariably by real-time RT-PCR from both hands after cleaning with alcohol hand rub (P-value <0.01). Both substances evaluated clinically were also tested in vitro for virucidal efficacy against Human rhinovirus2 (HRV2) using a standardized assay. Both tested substances were poor within the contact time used in the hand-cleaning test. In conclusion, thorough and conventional hand washing with water and soap can clean efficiently hands contaminated with the virus responsible for an extensive share of common cold episodes. Copyright © 2012 Wiley Periodicals, Inc.

Development of hand rehabilitation system for paralysis patient - universal design using wire-driven mechanism.

PubMed

Yamaura, Hiroshi; Matsushita, Kojiro; Kato, Ryu; Yokoi, Hiroshi

2009-01-01

We have developed a hand rehabilitation system for patients suffering from paralysis or contracture. It consists of two components: a hand rehabilitation machine, which moves human finger joints with motors, and a data glove, which provides control of the movement of finger joints attached to the rehabilitation machine. The machine is based on the arm structure type of hand rehabilitation machine; a motor indirectly moves a finger joint via a closed four-link mechanism. We employ a wire-driven mechanism and develop a compact design that can control all three joints (i.e., PIP, DIP and MP ) of a finger and that offers a wider range of joint motion than conventional systems. Furthermore, we demonstrate the hand rehabilitation process, finger joints of the left hand attached to the machine are controlled by the finger joints of the right hand wearing the data glove.

Frontoparietal Tracts Linked to Lateralized Hand Preference and Manual Specialization.

PubMed

Howells, Henrietta; Thiebaut de Schotten, Michel; Dell'Acqua, Flavio; Beyh, Ahmad; Zappalà, Giuseppe; Leslie, Anoushka; Simmons, Andrew; Murphy, Declan G; Catani, Marco

2018-04-21

Humans show a preference for using the right hand over the left for tasks and activities of everyday life. While experimental work in non-human primates has identified the neural systems responsible for reaching and grasping, the neural basis of lateralized motor behavior in humans remains elusive. The advent of diffusion imaging tractography for studying connectional anatomy in the living human brain provides the possibility of understanding the relationship between hemispheric asymmetry, hand preference, and manual specialization. In this study, diffusion tractography was used to demonstrate an interaction between hand preference and the asymmetry of frontoparietal tracts, specifically the dorsal branch of the superior longitudinal fasciculus, responsible for visuospatial integration and motor planning. This is in contrast to the corticospinal tract and the superior cerebellar peduncle, for which asymmetry was not related to hand preference. Asymmetry of the dorsal frontoparietal tract was also highly correlated with the degree of lateralization in tasks requiring visuospatial integration and fine motor control. These results suggest a common anatomical substrate for hand preference and lateralized manual specialization in frontoparietal tracts important for visuomotor processing.

Integration of robotics and neuroscience beyond the hand: What kind of synergies?. Comment on "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

NASA Astrophysics Data System (ADS)

d'Avella, Andrea

2016-07-01

Santello et al. [1] review an impressive amount of work on the control of biological and artificial hands that demonstrates how the concept of synergies can lead to a successful integration of robotics and neuroscience. Is it possible to generalize the same approach to the control of biological and artificial limbs and bodies beyond the hand? The human hand synergies that appear most relevant for robotic hands are those defined at the kinematic level, i.e. postural synergies [2]. Postural synergies capture the geometric relations among the many joints of the hand and allow for a low dimensional characterization and synthesis of the static hand postures involved in grasping and manipulating a large set of objects. However, many other complex motor skills such as walking, reaching, throwing, and catching require controlling multi-articular time-varying trajectories rather than static postures. Dynamic control of biological and artificial limbs and bodies, especially when geometric and inertial parameters are uncertain and the joints are compliant, poses great challenges. What kind of synergies might simplify the dynamic control of motor skills involving upper and lower limbs as well as the whole body?

Web-based interactive drone control using hand gesture

NASA Astrophysics Data System (ADS)

Zhao, Zhenfei; Luo, Hao; Song, Guang-Hua; Chen, Zhou; Lu, Zhe-Ming; Wu, Xiaofeng

2018-01-01

This paper develops a drone control prototype based on web technology with the aid of hand gesture. The uplink control command and downlink data (e.g., video) are transmitted by WiFi communication, and all the information exchange is realized on web. The control command is translated from various predetermined hand gestures. Specifically, the hardware of this friendly interactive control system is composed by a quadrotor drone, a computer vision-based hand gesture sensor, and a cost-effective computer. The software is simplified as a web-based user interface program. Aided by natural hand gestures, this system significantly reduces the complexity of traditional human-computer interaction, making remote drone operation more intuitive. Meanwhile, a web-based automatic control mode is provided in addition to the hand gesture control mode. For both operation modes, no extra application program is needed to be installed on the computer. Experimental results demonstrate the effectiveness and efficiency of the proposed system, including control accuracy, operation latency, etc. This system can be used in many applications such as controlling a drone in global positioning system denied environment or by handlers without professional drone control knowledge since it is easy to get started.

Web-based interactive drone control using hand gesture.

PubMed

Zhao, Zhenfei; Luo, Hao; Song, Guang-Hua; Chen, Zhou; Lu, Zhe-Ming; Wu, Xiaofeng

2018-01-01

This paper develops a drone control prototype based on web technology with the aid of hand gesture. The uplink control command and downlink data (e.g., video) are transmitted by WiFi communication, and all the information exchange is realized on web. The control command is translated from various predetermined hand gestures. Specifically, the hardware of this friendly interactive control system is composed by a quadrotor drone, a computer vision-based hand gesture sensor, and a cost-effective computer. The software is simplified as a web-based user interface program. Aided by natural hand gestures, this system significantly reduces the complexity of traditional human-computer interaction, making remote drone operation more intuitive. Meanwhile, a web-based automatic control mode is provided in addition to the hand gesture control mode. For both operation modes, no extra application program is needed to be installed on the computer. Experimental results demonstrate the effectiveness and efficiency of the proposed system, including control accuracy, operation latency, etc. This system can be used in many applications such as controlling a drone in global positioning system denied environment or by handlers without professional drone control knowledge since it is easy to get started.

The evolution of functional hand replacement: From iron prostheses to hand transplantation

PubMed Central

Zuo, Kevin J; Olson, Jaret L

2014-01-01

The hand is an integral component of the human body, with an incredible spectrum of functionality. In addition to possessing gross and fine motor capabilities essential for physical survival, the hand is fundamental to social conventions, enabling greeting, grooming, artistic expression and syntactical communication. The loss of one or both hands is, thus, a devastating experience, requiring significant psychological support and physical rehabilitation. The majority of hand amputations occur in working-age males, most commonly as a result of work-related trauma or as casualties sustained during combat. For millennia, humans have used state-of-the-art technology to design clever devices to facilitate the reintegration of hand amputees into society. The present article provides a historical overview of the progress in replacing a missing hand, from early iron hands intended primarily for use in battle, to today’s standard body-powered and myoelectric prostheses, to revolutionary advancements in the restoration of sensorimotor control with targeted reinnervation and hand transplantation. PMID:25152647

Object-based task-level control: A hierarchical control architecture for remote operation of space robots

NASA Technical Reports Server (NTRS)

Stevens, H. D.; Miles, E. S.; Rock, S. J.; Cannon, R. H.

1994-01-01

Expanding man's presence in space requires capable, dexterous robots capable of being controlled from the Earth. Traditional 'hand-in-glove' control paradigms require the human operator to directly control virtually every aspect of the robot's operation. While the human provides excellent judgment and perception, human interaction is limited by low bandwidth, delayed communications. These delays make 'hand-in-glove' operation from Earth impractical. In order to alleviate many of the problems inherent to remote operation, Stanford University's Aerospace Robotics Laboratory (ARL) has developed the Object-Based Task-Level Control architecture. Object-Based Task-Level Control (OBTLC) removes the burden of teleoperation from the human operator and enables execution of tasks not possible with current techniques. OBTLC is a hierarchical approach to control where the human operator is able to specify high-level, object-related tasks through an intuitive graphical user interface. Infrequent task-level command replace constant joystick operations, eliminating communications bandwidth and time delay problems. The details of robot control and task execution are handled entirely by the robot and computer control system. The ARL has implemented the OBTLC architecture on a set of Free-Flying Space Robots. The capability of the OBTLC architecture has been demonstrated by controlling the ARL Free-Flying Space Robots from NASA Ames Research Center.

[Study on an Exoskeleton Hand Function Training Device].

PubMed

Hu, Xin; Zhang, Ying; Li, Jicai; Yi, Jinhua; Yu, Hongliu; He, Rongrong

2016-02-01

Based on the structure and motion bionic principle of the normal adult fingers, biological characteristics of human hands were analyzed, and a wearable exoskeleton hand function training device for the rehabilitation of stroke patients or patients with hand trauma was designed. This device includes the exoskeleton mechanical structure and the electromyography (EMG) control system. With adjustable mechanism, the device was capable to fit different finger lengths, and by capturing the EMG of the users' contralateral limb, the motion state of the exoskeleton hand was controlled. Then driven by the device, the user's fingers conducting adduction/abduction rehabilitation training was carried out. Finally, the mechanical properties and training effect of the exoskeleton hand were verified through mechanism simulation and the experiments on the experimental prototype of the wearable exoskeleton hand function training device.

An effective 3-fingered augmenting exoskeleton for the human hand.

PubMed

Gearhart, C J; Varone, B; Stella, M H; BuSha, B F

2016-08-01

Every year, thousands of Americans suffer from pathological and traumatic events that result in loss of dexterity and strength of the hand. Although many supportive devices have been designed to restore functional hand movement, most are very complex and expensive. The goal of this project was to design and implement a cost-effective, electrically powered exoskeleton for the human hand that could improve grasping strength. A 3-D printed thermoplastic exoskeleton that allowed independent and enhanced movement of the index, middle and ring fingers was constructed. In addition, a 3-D printed structure was designed to house three linear actuators, an Arduino-based control system, and a power supply. A single force sensing resistor was located on the lower inner-surface of the index fingertip which was used to proportionally activate the three motors, one motor per finger, as a function of finger force applied to the sensor. The device was tested on 4 normal human subjects. Results showed that the activation of the motor control system significantly reduced the muscle effort needed to maintain a sub-maximal grasp effort.

Ten-dimensional anthropomorphic arm control in a human brain-machine interface: difficulties, solutions, and limitations

NASA Astrophysics Data System (ADS)

Wodlinger, B.; Downey, J. E.; Tyler-Kabara, E. C.; Schwartz, A. B.; Boninger, M. L.; Collinger, J. L.

2015-02-01

Objective. In a previous study we demonstrated continuous translation, orientation and one-dimensional grasping control of a prosthetic limb (seven degrees of freedom) by a human subject with tetraplegia using a brain-machine interface (BMI). The current study, in the same subject, immediately followed the previous work and expanded the scope of the control signal by also extracting hand-shape commands from the two 96-channel intracortical electrode arrays implanted in the subject’s left motor cortex. Approach. Four new control signals, dictating prosthetic hand shape, replaced the one-dimensional grasping in the previous study, allowing the subject to control the prosthetic limb with ten degrees of freedom (three-dimensional (3D) translation, 3D orientation, four-dimensional hand shaping) simultaneously. Main results. Robust neural tuning to hand shaping was found, leading to ten-dimensional (10D) performance well above chance levels in all tests. Neural unit preferred directions were broadly distributed through the 10D space, with the majority of units significantly tuned to all ten dimensions, instead of being restricted to isolated domains (e.g. translation, orientation or hand shape). The addition of hand shaping emphasized object-interaction behavior. A fundamental component of BMIs is the calibration used to associate neural activity to intended movement. We found that the presence of an object during calibration enhanced successful shaping of the prosthetic hand as it closed around the object during grasping. Significance. Our results show that individual motor cortical neurons encode many parameters of movement, that object interaction is an important factor when extracting these signals, and that high-dimensional operation of prosthetic devices can be achieved with simple decoding algorithms. ClinicalTrials.gov Identifier: NCT01364480.

Design of a force reflecting hand controller for space telemanipulation studies

NASA Technical Reports Server (NTRS)

Paines, J. D. B.

1987-01-01

The potential importance of space telemanipulator systems is reviewed, along with past studies of master-slave manipulation using a generalized force reflecting master arm. Problems concerning their dynamic interaction with the human operator have been revealed in the use of these systems, with marked differences between 1-g and simulated weightless conditions. A study is outlined to investigate the optimization of the man machine dynamics of master-slave manipulation, and a set of specifications is determined for the apparatus necessary to perform this investigation. This apparatus is a one degree of freedom force reflecting hand controller with closed loop servo control which enables it to simulate arbitrary dynamic properties to high bandwidth. Design of the complete system and its performance is discussed. Finally, the experimental adjustment of the hand controller dynamics for smooth manual control performance with good operator force perception is described, resulting in low inertia, viscously damped hand controller dynamics.

Development of Pneumatic Robot Hand and Construction of Master-Slave System

NASA Astrophysics Data System (ADS)

Tsujiuchi, Nobutaka; Koizumi, Takayuki; Nishino, Shinya; Komatsubara, Hiroyuki; Kudawara, Tatsuwo; Hirano, Masanori

Recently, research and development has focused on robots that work in place of people. It is necessary for robots to perform the same flexible motions as people. Additionally, such robots need to incorporate high-level safety features in order not to injure people. For creation of such robots, we need to develop a robot hand that functions like a human hand. At the same time, this type of robot hand can be used as an artificial hand. Here, we present artificial muscle-type pneumatic actuators as the driving source of a robot hand that is both safe and flexible. Some development of robot hands using pneumatic actuators has already taken place. But, until now, when a pneumatic actuator is used, a big compressor is needed. So, the driving system also needs to be big; enlargement of the driving system is a major problem. Consequently, in this research, we develop a low-pressure, low-volume pneumatic actuator for driving a robot hand that works flexibly and safely on the assumption that it will be in contact with people. We develop a five-fingered robot hand with pneumatic actuators. And, we construct a master-slave system to enable the robot hand to perform the same operations as a human hand. We make a 1-link arm that has one degree of freedom using a pneumatic actuator, and construct a control system for the 1-link arm and verify its control performance.

Cortex Inspired Model for Inverse Kinematics Computation for a Humanoid Robotic Finger

PubMed Central

Gentili, Rodolphe J.; Oh, Hyuk; Molina, Javier; Reggia, James A.; Contreras-Vidal, José L.

2013-01-01

In order to approach human hand performance levels, artificial anthropomorphic hands/fingers have increasingly incorporated human biomechanical features. However, the performance of finger reaching movements to visual targets involving the complex kinematics of multi-jointed, anthropomorphic actuators is a difficult problem. This is because the relationship between sensory and motor coordinates is highly nonlinear, and also often includes mechanical coupling of the two last joints. Recently, we developed a cortical model that learns the inverse kinematics of a simulated anthropomorphic finger. Here, we expand this previous work by assessing if this cortical model is able to learn the inverse kinematics for an actual anthropomorphic humanoid finger having its two last joints coupled and controlled by pneumatic muscles. The findings revealed that single 3D reaching movements, as well as more complex patterns of motion of the humanoid finger, were accurately and robustly performed by this cortical model while producing kinematics comparable to those of humans. This work contributes to the development of a bioinspired controller providing adaptive, robust and flexible control of dexterous robotic and prosthetic hands. PMID:23366569

Gesture-Based Robot Control with Variable Autonomy from the JPL Biosleeve

NASA Technical Reports Server (NTRS)

Wolf, Michael T.; Assad, Christopher; Vernacchia, Matthew T.; Fromm, Joshua; Jethani, Henna L.

2013-01-01

This paper presents a new gesture-based human interface for natural robot control. Detailed activity of the user's hand and arm is acquired via a novel device, called the BioSleeve, which packages dry-contact surface electromyography (EMG) and an inertial measurement unit (IMU) into a sleeve worn on the forearm. The BioSleeve's accompanying algorithms can reliably decode as many as sixteen discrete hand gestures and estimate the continuous orientation of the forearm. These gestures and positions are mapped to robot commands that, to varying degrees, integrate with the robot's perception of its environment and its ability to complete tasks autonomously. This flexible approach enables, for example, supervisory point-to-goal commands, virtual joystick for guarded teleoperation, and high degree of freedom mimicked manipulation, all from a single device. The BioSleeve is meant for portable field use; unlike other gesture recognition systems, use of the BioSleeve for robot control is invariant to lighting conditions, occlusions, and the human-robot spatial relationship and does not encumber the user's hands. The BioSleeve control approach has been implemented on three robot types, and we present proof-of-principle demonstrations with mobile ground robots, manipulation robots, and prosthetic hands.

Design and control of five fingered under-actuated robotic hand

NASA Astrophysics Data System (ADS)

Sahoo, Biswojit; Parida, Pramod Kumar

2018-04-01

Now a day's research regarding humanoid robots and its application in different fields (industry, household, rehabilitation and exploratory) is going on entire the globe. Among which a challenging topic is to design a dexterous robotic hand which not only can perform as a hand of a robot but also can be used in re habilitation. The basic key concern is a dexterous robot hand which can be able to mimic the function of biological hand to perform different operations. This thesis work is regarding design and control of a under-actuated robotic hand consisting of four under actuated fingers (index finger, middle finger, little finger and ring finger ) , a thumb and a dexterous palm which can copy the motions and grasp type of human hand which having 21degrees of freedom instead of 25Degree Of Freedom.

A cortically-inspired model for inverse kinematics computation of a humanoid finger with mechanically coupled joints.

PubMed

Gentili, Rodolphe J; Oh, Hyuk; Kregling, Alissa V; Reggia, James A

2016-05-19

The human hand's versatility allows for robust and flexible grasping. To obtain such efficiency, many robotic hands include human biomechanical features such as fingers having their two last joints mechanically coupled. Although such coupling enables human-like grasping, controlling the inverse kinematics of such mechanical systems is challenging. Here we propose a cortical model for fine motor control of a humanoid finger, having its two last joints coupled, that learns the inverse kinematics of the effector. This neural model functionally mimics the population vector coding as well as sensorimotor prediction processes of the brain's motor/premotor and parietal regions, respectively. After learning, this neural architecture could both overtly (actual execution) and covertly (mental execution or motor imagery) perform accurate, robust and flexible finger movements while reproducing the main human finger kinematic states. This work contributes to developing neuro-mimetic controllers for dexterous humanoid robotic/prosthetic upper-extremities, and has the potential to promote human-robot interactions.

Improvement of Hand Movement on Visual Target Tracking by Assistant Force of Model-Based Compensator

NASA Astrophysics Data System (ADS)

Ide, Junko; Sugi, Takenao; Nakamura, Masatoshi; Shibasaki, Hiroshi

Human motor control is achieved by the appropriate motor commands generating from the central nerve system. A test of visual target tracking is one of the effective methods for analyzing the human motor functions. We have previously examined a possibility for improving the hand movement on visual target tracking by additional assistant force through a simulation study. In this study, a method for compensating the human hand movement on visual target tracking by adding an assistant force was proposed. Effectiveness of the compensation method was investigated through the experiment for four healthy adults. The proposed compensator precisely improved the reaction time, the position error and the variability of the velocity of the human hand. The model-based compensator proposed in this study is constructed by using the measurement data on visual target tracking for each subject. The properties of the hand movement for different subjects can be reflected in the structure of the compensator. Therefore, the proposed method has possibility to adjust the individual properties of patients with various movement disorders caused from brain dysfunctions.

Comparison of human and electronic observation for the measurement of compliance with hand hygiene.

PubMed

Filho, Miguel Almeida O; Marra, Alexandre R; Magnus, Thyago Pereira; Rodrigues, Rodrigo Dias; Prado, Marcelo; de Souza Santini, Tales Roberto; da Silva Victor, Elivane; Ishibe, Eder Issao; Pavão Dos Santos, Oscar Fernando; Edmond, Michael B

2014-11-01

Monitoring of hand hygiene is an important part of the improvement of hospital quality indicators. This study was prospectively performed over a 14-week (electronic observer) period from December 3, 2013-March 9, 2014, to evaluate hand hygiene compliance in an adult step-down unit. We compared electronic handwash counters with the application of radiofrequency identification (RFID - ZigBee; i-Healthsys, São Carlos, Brazil) (electronic observer), which counts each activation of the alcohol gel dispenser to direct observation (human observer) using the iScrub application. For the overall time period of simultaneous electronic and human observation, we found that the electronic observer identified 414 hand hygiene episodes, whereas the human observers identified 448 episodes. Therefore, we found 92% (95% confidence interval [CI], 90%-95%) overall concordance (414/448), with an intraclass correlation coefficient of .87 (95% CI, 0.77-0.92). Our RFID (ZigBee) system showed good accuracy (92%) and is a useful method to monitor hand hygiene compliance. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Vision-Based Pose Estimation for Robot-Mediated Hand Telerehabilitation

PubMed Central

Airò Farulla, Giuseppe; Pianu, Daniele; Cempini, Marco; Cortese, Mario; Russo, Ludovico O.; Indaco, Marco; Nerino, Roberto; Chimienti, Antonio; Oddo, Calogero M.; Vitiello, Nicola

2016-01-01

Vision-based Pose Estimation (VPE) represents a non-invasive solution to allow a smooth and natural interaction between a human user and a robotic system, without requiring complex calibration procedures. Moreover, VPE interfaces are gaining momentum as they are highly intuitive, such that they can be used from untrained personnel (e.g., a generic caregiver) even in delicate tasks as rehabilitation exercises. In this paper, we present a novel master–slave setup for hand telerehabilitation with an intuitive and simple interface for remote control of a wearable hand exoskeleton, named HX. While performing rehabilitative exercises, the master unit evaluates the 3D position of a human operator’s hand joints in real-time using only a RGB-D camera, and commands remotely the slave exoskeleton. Within the slave unit, the exoskeleton replicates hand movements and an external grip sensor records interaction forces, that are fed back to the operator-therapist, allowing a direct real-time assessment of the rehabilitative task. Experimental data collected with an operator and six volunteers are provided to show the feasibility of the proposed system and its performances. The results demonstrate that, leveraging on our system, the operator was able to directly control volunteers’ hands movements. PMID:26861333

Vision-Based Pose Estimation for Robot-Mediated Hand Telerehabilitation.

PubMed

Airò Farulla, Giuseppe; Pianu, Daniele; Cempini, Marco; Cortese, Mario; Russo, Ludovico O; Indaco, Marco; Nerino, Roberto; Chimienti, Antonio; Oddo, Calogero M; Vitiello, Nicola

2016-02-05

Vision-based Pose Estimation (VPE) represents a non-invasive solution to allow a smooth and natural interaction between a human user and a robotic system, without requiring complex calibration procedures. Moreover, VPE interfaces are gaining momentum as they are highly intuitive, such that they can be used from untrained personnel (e.g., a generic caregiver) even in delicate tasks as rehabilitation exercises. In this paper, we present a novel master-slave setup for hand telerehabilitation with an intuitive and simple interface for remote control of a wearable hand exoskeleton, named HX. While performing rehabilitative exercises, the master unit evaluates the 3D position of a human operator's hand joints in real-time using only a RGB-D camera, and commands remotely the slave exoskeleton. Within the slave unit, the exoskeleton replicates hand movements and an external grip sensor records interaction forces, that are fed back to the operator-therapist, allowing a direct real-time assessment of the rehabilitative task. Experimental data collected with an operator and six volunteers are provided to show the feasibility of the proposed system and its performances. The results demonstrate that, leveraging on our system, the operator was able to directly control volunteers' hands movements.

Experimental and simulation studies of hard contact in force reflecting teleoperation

NASA Technical Reports Server (NTRS)

Hannaford, Blake; Anderson, Robert

1988-01-01

Experiments and simulations of a single-axis force-reflecting teleoperation system have been conducted to investigate the problem of contacting a hard environment and maintaining a controlled force in teleoperation in which position is fed forward from the hand controller (master) to the manipulator (slave), and force is fed back to the human operator through motors in the master. The simulations, using an electrical circuit model, reproduce the behavior of the real system, including effects of human operator biomechanics. It is shown that human operator properties, which vary as a result of different types of grasp of the handle, affect the stability of the system in the hard-contact task. The effect of a heavier grasp on the handle is equivalent to increased hand-controller velocity damping in terms of the systems stability in the contact task, but control system damping sufficient to guarantee stable contact results in perceptible sluggishness of the control handle's response in free motion. These results suggest that human operator biomechanics must be taken into account to guarantee stable and ergonomic performance of advanced teleoperators.

Binocular and Monocular Depth Cues in Online Feedback Control of 3-D Pointing Movement

PubMed Central

Hu, Bo; Knill, David C.

2012-01-01

Previous work has shown that humans continuously use visual feedback of the hand to control goal-directed movements online. In most studies, visual error signals were predominantly in the image plane and thus were available in an observer’s retinal image. We investigate how humans use visual feedback about finger depth provided by binocular and monocular depth cues to control pointing movements. When binocularly viewing a scene in which the hand movement was made in free space, subjects were about 60 ms slower in responding to perturbations in depth than in the image plane. When monocularly viewing a scene designed to maximize the available monocular cues to finger depth (motion, changing size and cast shadows), subjects showed no response to perturbations in depth. Thus, binocular cues from the finger are critical to effective online control of hand movements in depth. An optimal feedback controller that takes into account of the low peripheral stereoacuity and inherent ambiguity in cast shadows can explain the difference in response time in the binocular conditions and lack of response in monocular conditions. PMID:21724567

Control of robot assistant for rehabilitation of upper extremities.

PubMed

Kostić, Miloš D; Popović, Mirjana B; Popović, Dejan B

2012-01-01

The assisted movement in humans with paresis of upper extremities is becoming popular for neurorehabilitation. We propose a novel method for trajectory selection and assistance control. This paper presents simulation of a planar two degrees of freedom robot that assists horizontal movement of the hand. The control assumes that during the exercise the hand needs to follow healthy alike trajectories. The robot is assumed to provide minimal assistance and operate as a teacher of the movement.

Intermanual Transfer of Shapes in Preterm Human Infants from 33 to 34 + 6 Weeks Postconceptional Age

ERIC Educational Resources Information Center

Lejeune, Fleur; Marcus, Leila; Berne-Audeoud, Frederique; Streri, Arlette; Debillon, Thierry; Gentaz, Edouard

2012-01-01

This study investigated the ability of preterm infants to learn an object shape with one hand and discriminate a new shape in the opposite hand (without visual control). Twenty-four preterm infants between 33 and 34 + 6 gestational weeks received a tactile habituation task with either their right or left hand followed by a tactile discrimination…

Abstract and proportional myoelectric control for multi-fingered hand prostheses.

PubMed

Pistohl, Tobias; Cipriani, Christian; Jackson, Andrew; Nazarpour, Kianoush

2013-12-01

Powered hand prostheses with many degrees of freedom are moving from research into the market for prosthetics. In order to make use of the prostheses' full functionality, it is essential to study efficient ways of high dimensional myoelectric control. Human subjects can rapidly learn to employ electromyographic (EMG) activity of several hand and arm muscles to control the position of a cursor on a computer screen, even if the muscle-cursor map contradicts directions in which the muscles would act naturally. But can a similar control scheme be translated into real-time operation of a dexterous robotic hand? We found that despite different degrees of freedom in the effector output, the learning process for controlling a robotic hand was surprisingly similar to that for a virtual two-dimensional cursor. Control signals were derived from the EMG in two different ways, with a linear and a Bayesian filter, to test how stable user intentions could be conveyed through them. Our analysis indicates that without visual feedback, control accuracy benefits from filters that reject high EMG amplitudes. In summary, we conclude that findings on myoelectric control principles, studied in abstract, virtual tasks can be transferred to real-life prosthetic applications.

Sensing And Force-Reflecting Exoskeleton

NASA Technical Reports Server (NTRS)

Eberman, Brian; Fontana, Richard; Marcus, Beth

1993-01-01

Sensing and force-reflecting exoskeleton (SAFiRE) provides control signals to robot hand and force feedback from robot hand to human operator. Operator makes robot hand touch objects gently and manipulates them finely without exerting excessive forces. Device attaches to operator's hand; comfortable and lightweight. Includes finger exoskeleton, cable mechanical transmission, two dc servomotors, partial thumb exoskeleton, harness, amplifier box, two computer circuit boards, and software. Transduces motion of index finger and thumb. Video monitor of associated computer displays image corresponding to motion.

Tactile interactions activate mirror system regions in the human brain.

PubMed

McKyton, Ayelet

2011-12-07

Communicating with others is essential for the development of a society. Although types of communications, such as language and visual gestures, were thoroughly investigated in the past, little research has been done to investigate interactions through touch. To study this we used functional magnetic resonance imaging. Twelve participants were scanned with their eyes covered while stroking four kinds of items, representing different somatosensory stimuli: a human hand, a realistic rubber hand, an object, and a simple texture. Although the human and the rubber hands had the same overall shape, in three regions there was significantly more blood oxygen level dependent activation when touching the real hand: the anterior medial prefrontal cortex, the ventral premotor cortex, and the posterior superior temporal cortex. The last two regions are part of the mirror network and are known to be activated through visual interactions such as gestures. Interestingly, in this study, these areas were activated through a somatosensory interaction. A control experiment was performed to eliminate confounds of temperature, texture, and imagery, suggesting that the activation in these areas was correlated with the touch of a human hand. These results reveal the neuronal network working behind human tactile interactions, and highlight the participation of the mirror system in such functions.

Spoken language and arm gestures are controlled by the same motor control system.

PubMed

Gentilucci, Maurizio; Dalla Volta, Riccardo

2008-06-01

Arm movements can influence language comprehension much as semantics can influence arm movement planning. Arm movement itself can be used as a linguistic signal. We reviewed neurophysiological and behavioural evidence that manual gestures and vocal language share the same control system. Studies of primate premotor cortex and, in particular, of the so-called "mirror system", including humans, suggest the existence of a dual hand/mouth motor command system involved in ingestion activities. This may be the platform on which a combined manual and vocal communication system was constructed. In humans, speech is typically accompanied by manual gesture, speech production itself is influenced by executing or observing transitive hand actions, and manual actions play an important role in the development of speech, from the babbling stage onwards. Behavioural data also show reciprocal influence between word and symbolic gestures. Neuroimaging and repetitive transcranial magnetic stimulation (rTMS) data suggest that the system governing both speech and gesture is located in Broca's area. In general, the presented data support the hypothesis that the hand motor-control system is involved in higher order cognition.

Neuroprosthetic-enabled control of graded arm muscle contraction in a paralyzed human.

PubMed

Friedenberg, David A; Schwemmer, Michael A; Landgraf, Andrew J; Annetta, Nicholas V; Bockbrader, Marcia A; Bouton, Chad E; Zhang, Mingming; Rezai, Ali R; Mysiw, W Jerry; Bresler, Herbert S; Sharma, Gaurav

2017-08-21

Neuroprosthetics that combine a brain computer interface (BCI) with functional electrical stimulation (FES) can restore voluntary control of a patients' own paralyzed limbs. To date, human studies have demonstrated an "all-or-none" type of control for a fixed number of pre-determined states, like hand-open and hand-closed. To be practical for everyday use, a BCI-FES system should enable smooth control of limb movements through a continuum of states and generate situationally appropriate, graded muscle contractions. Crucially, this functionality will allow users of BCI-FES neuroprosthetics to manipulate objects of different sizes and weights without dropping or crushing them. In this study, we present the first evidence that using a BCI-FES system, a human with tetraplegia can regain volitional, graded control of muscle contraction in his paralyzed limb. In addition, we show the critical ability of the system to generalize beyond training states and accurately generate wrist flexion states that are intermediate to training levels. These innovations provide the groundwork for enabling enhanced and more natural fine motor control of paralyzed limbs by BCI-FES neuroprosthetics.

Control Model for Dampening Hand Vibrations Using Information of Internal and External Coordinates

PubMed Central

Togo, Shunta; Kagawa, Takahiro; Uno, Yoji

2015-01-01

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. PMID:25876037

When does tool use become distinctively human?: Hammering in young children

PubMed Central

Kahrs, Björn; Lockman, Jeffrey J.; Jung, Wendy

2013-01-01

This study examines the development of hammering within an ontogenetic and evolutionary framework using motion-capture technology. Twenty-four right-handed toddlers (19–35 months) wore reflective markers while hammering a peg into a peg-board. The study focuses on the motor characteristics that make tool use uniquely human: wrist involvement, lateralization, and handle use. Older children showed more distally controlled movements, characterized by relatively more reliance on the wrist, but only when hammering with their right hand. Greater age, use of the right hand, and more wrist involvement were associated with higher accuracy; handle use did not systematically change with age. Collectively, the results provide new insights about the emergence of hammering in young children and when hammering begins to manifest distinctively human characteristics. PMID:24128178

Development of a Self-Balancing Human Transportation Vehicle for the Teaching of Feedback Control

ERIC Educational Resources Information Center

Lin, Shui-Chun; Tsai, Ching-Chih

2009-01-01

Control systems education often needs to design interesting hands-on exercises that keep students interested in the control theory presented in lectures. These exercises include system modeling, system analyses, controller syntheses, implementation, experimentation, and performance evaluation of a control system. This paper presents an interesting…

The Treatment of Smith's Invisible Hand

ERIC Educational Resources Information Center

Wight, Jonathan B.

2007-01-01

Adam Smith used the metaphor of an invisible hand to represent the instincts of human nature that direct behavior. Moderated by self-control and guided by proper institutional incentives, actions grounded in instincts can be shown to generate a beneficial social order even if not intended. Smith's concept, however, has been diluted and distorted…

Engaging Cervical Spinal Cord Networks to Reenable Volitional Control of Hand Function in Tetraplegic Patients.

PubMed

Lu, Daniel C; Edgerton, V Reggie; Modaber, Morteza; AuYong, Nicholas; Morikawa, Erika; Zdunowski, Sharon; Sarino, Melanie E; Sarrafzadeh, Majid; Nuwer, Marc R; Roy, Roland R; Gerasimenko, Yury

2016-11-01

Paralysis of the upper limbs from spinal cord injury results in an enormous loss of independence in an individual's daily life. Meaningful improvement in hand function is rare after 1 year of tetraparesis. Therapeutic developments that result in even modest gains in hand volitional function will significantly affect the quality of life for patients afflicted with high cervical injury. The ability to neuromodulate the lumbosacral spinal circuitry via epidural stimulation in regaining postural function and volitional control of the legs has been recently shown. A key question is whether a similar neuromodulatory strategy can be used to improve volitional motor control of the upper limbs, that is, performance of motor tasks considered to be less "automatic" than posture and locomotion. In this study, the effects of cervical epidural stimulation on hand function are characterized in subjects with chronic cervical cord injury. Herein we show that epidural stimulation can be applied to the chronic injured human cervical spinal cord to promote volitional hand function. Two subjects implanted with a cervical epidural electrode array demonstrated improved hand strength (approximately 3-fold) and volitional hand control in the presence of epidural stimulation. The present data are sufficient to suggest that hand motor function in individuals with chronic tetraplegia can be improved with cervical cord neuromodulation and thus should be comprehensively explored as a possible clinical intervention. © The Author(s) 2016.

Development of a Prototype Over-Actuated Biomimetic Prosthetic Hand

PubMed Central

Williams, Matthew R.; Walter, Wayne

2015-01-01

The loss of a hand can greatly affect quality of life. A prosthetic device that can mimic normal hand function is very important to physical and mental recuperation after hand amputation, but the currently available prosthetics do not fully meet the needs of the amputee community. Most prosthetic hands are not dexterous enough to grasp a variety of shaped objects, and those that are tend to be heavy, leading to discomfort while wearing the device. In order to attempt to better simulate human hand function, a dexterous hand was developed that uses an over-actuated mechanism to form grasp shape using intrinsic joint mounted motors in addition to a finger tendon to produce large flexion force for a tight grip. This novel actuation method allows the hand to use small actuators for grip shape formation, and the tendon to produce high grip strength. The hand was capable of producing fingertip flexion force suitable for most activities of daily living. In addition, it was able to produce a range of grasp shapes with natural, independent finger motion, and appearance similar to that of a human hand. The hand also had a mass distribution more similar to a natural forearm and hand compared to contemporary prosthetics due to the more proximal location of the heavier components of the system. This paper describes the design of the hand and controller, as well as the test results. PMID:25790306

Gaussian Process Autoregression for Simultaneous Proportional Multi-Modal Prosthetic Control With Natural Hand Kinematics.

PubMed

Xiloyannis, Michele; Gavriel, Constantinos; Thomik, Andreas A C; Faisal, A Aldo

2017-10-01

Matching the dexterity, versatility, and robustness of the human hand is still an unachieved goal in bionics, robotics, and neural engineering. A major limitation for hand prosthetics lies in the challenges of reliably decoding user intention from muscle signals when controlling complex robotic hands. Most of the commercially available prosthetic hands use muscle-related signals to decode a finite number of predefined motions and some offer proportional control of open/close movements of the whole hand. Here, in contrast, we aim to offer users flexible control of individual joints of their artificial hand. We propose a novel framework for decoding neural information that enables a user to independently control 11 joints of the hand in a continuous manner-much like we control our natural hands. Toward this end, we instructed six able-bodied subjects to perform everyday object manipulation tasks combining both dynamic, free movements (e.g., grasping) and isometric force tasks (e.g., squeezing). We recorded the electromyographic and mechanomyographic activities of five extrinsic muscles of the hand in the forearm, while simultaneously monitoring 11 joints of hand and fingers using a sensorized data glove that tracked the joints of the hand. Instead of learning just a direct mapping from current muscle activity to intended hand movement, we formulated a novel autoregressive approach that combines the context of previous hand movements with instantaneous muscle activity to predict future hand movements. Specifically, we evaluated a linear vector autoregressive moving average model with exogenous inputs and a novel Gaussian process ( ) autoregressive framework to learn the continuous mapping from hand joint dynamics and muscle activity to decode intended hand movement. Our approach achieves high levels of performance (RMSE of 8°/s and ). Crucially, we use a small set of sensors that allows us to control a larger set of independently actuated degrees of freedom of a hand. This novel undersensored control is enabled through the combination of nonlinear autoregressive continuous mapping between muscle activity and joint angles. The system evaluates the muscle signals in the context of previous natural hand movements. This enables us to resolve ambiguities in situations, where muscle signals alone cannot determine the correct action as we evaluate the muscle signals in their context of natural hand movements. autoregression is a particularly powerful approach which makes not only a prediction based on the context but also represents the associated uncertainty of its predictions, thus enabling the novel notion of risk-based control in neuroprosthetics. Our results suggest that autoregressive approaches with exogenous inputs lend themselves for natural, intuitive, and continuous control in neurotechnology, with the particular focus on prosthetic restoration of natural limb function, where high dexterity is required for complex movements.

Sex differences in motor and cognitive abilities predicted from human evolutionary history with some implications for models of the visual system.

PubMed

Sanders, Geoff

2013-01-01

This article expands the knowledge base available to sex researchers by reviewing recent evidence for sex differences in coincidence-anticipation timing (CAT), motor control with the hand and arm, and visual processing of stimuli in near and far space. In CAT, the differences are between sex and, therefore, typical of other widely reported sex differences. Men perform CAT tasks with greater accuracy and precision than women, who tend to underestimate time to arrival. Null findings arise because significant sex differences are found with easy but not with difficult tasks. The differences in motor control and visual processing are within sex, and they underlie reciprocal patterns of performance in women and men. Motor control is exerted better by women with the hand than the arm. In contrast, men showed the reverse pattern. Visual processing is performed better by women with stimuli within hand reach (near space) as opposed to beyond hand reach (far space); men showed the reverse pattern. The sex differences seen in each of these three abilities are consistent with the evolutionary selection of men for hunting-related skills and women for gathering-related skills. The implications of the sex differences in visual processing for two visual system models of human vision are discussed.

The relationship between human security, demand for arms and disarmament in the horn of Africa.

PubMed

Gebrewold, Kiflemariam

2002-01-01

The drive to find security through possession of weapons is linked to the history and culture of a social group. Amongst pastoralists in the Horn of Africa there is a failure of security through state systems such as police and the recent replacement of less-lethal traditional weapons by small arms and other light weapons. A warrior or vendetta culture with these arms leads to violent inter-clan clashes with many casualties, although traditional methods of weapons control still seem operational within clans. Understanding the drive to seek weapons is essential in finding ways to control their use. Improving the capacities of the police must come hand in hand with human rights training and an end to corruption. Further work is required on how traditional methods of arms control can be co-operatively linked with state controls.

Selection of suitable hand gestures for reliable myoelectric human computer interface.

PubMed

Castro, Maria Claudia F; Arjunan, Sridhar P; Kumar, Dinesh K

2015-04-09

Myoelectric controlled prosthetic hand requires machine based identification of hand gestures using surface electromyogram (sEMG) recorded from the forearm muscles. This study has observed that a sub-set of the hand gestures have to be selected for an accurate automated hand gesture recognition, and reports a method to select these gestures to maximize the sensitivity and specificity. Experiments were conducted where sEMG was recorded from the muscles of the forearm while subjects performed hand gestures and then was classified off-line. The performances of ten gestures were ranked using the proposed Positive-Negative Performance Measurement Index (PNM), generated by a series of confusion matrices. When using all the ten gestures, the sensitivity and specificity was 80.0% and 97.8%. After ranking the gestures using the PNM, six gestures were selected and these gave sensitivity and specificity greater than 95% (96.5% and 99.3%); Hand open, Hand close, Little finger flexion, Ring finger flexion, Middle finger flexion and Thumb flexion. This work has shown that reliable myoelectric based human computer interface systems require careful selection of the gestures that have to be recognized and without such selection, the reliability is poor.

Electromyography (EMG) signal recognition using combined discrete wavelet transform based adaptive neuro-fuzzy inference systems (ANFIS)

NASA Astrophysics Data System (ADS)

Arozi, Moh; Putri, Farika T.; Ariyanto, Mochammad; Khusnul Ari, M.; Munadi, Setiawan, Joga D.

2017-01-01

People with disabilities are increasing from year to year either due to congenital factors, sickness, accident factors and war. One form of disability is the case of interruptions of hand function. The condition requires and encourages the search for solutions in the form of creating an artificial hand with the ability as a human hand. The development of science in the field of neuroscience currently allows the use of electromyography (EMG) to control the motion of artificial prosthetic hand into the necessary use of EMG as an input signal to control artificial prosthetic hand. This study is the beginning of a significant research planned in the development of artificial prosthetic hand with EMG signal input. This initial research focused on the study of EMG signal recognition. Preliminary results show that the EMG signal recognition using combined discrete wavelet transform and Adaptive Neuro-Fuzzy Inference System (ANFIS) produces accuracy 98.3 % for training and 98.51% for testing. Thus the results can be used as an input signal for Simulink block diagram of a prosthetic hand that will be developed on next study. The research will proceed with the construction of artificial prosthetic hand along with Simulink program controlling and integrating everything into one system.

Depth Camera-Based 3D Hand Gesture Controls with Immersive Tactile Feedback for Natural Mid-Air Gesture Interactions

PubMed Central

Kim, Kwangtaek; Kim, Joongrock; Choi, Jaesung; Kim, Junghyun; Lee, Sangyoun

2015-01-01

Vision-based hand gesture interactions are natural and intuitive when interacting with computers, since we naturally exploit gestures to communicate with other people. However, it is agreed that users suffer from discomfort and fatigue when using gesture-controlled interfaces, due to the lack of physical feedback. To solve the problem, we propose a novel complete solution of a hand gesture control system employing immersive tactile feedback to the user's hand. For this goal, we first developed a fast and accurate hand-tracking algorithm with a Kinect sensor using the proposed MLBP (modified local binary pattern) that can efficiently analyze 3D shapes in depth images. The superiority of our tracking method was verified in terms of tracking accuracy and speed by comparing with existing methods, Natural Interaction Technology for End-user (NITE), 3D Hand Tracker and CamShift. As the second step, a new tactile feedback technology with a piezoelectric actuator has been developed and integrated into the developed hand tracking algorithm, including the DTW (dynamic time warping) gesture recognition algorithm for a complete solution of an immersive gesture control system. The quantitative and qualitative evaluations of the integrated system were conducted with human subjects, and the results demonstrate that our gesture control with tactile feedback is a promising technology compared to a vision-based gesture control system that has typically no feedback for the user's gesture inputs. Our study provides researchers and designers with informative guidelines to develop more natural gesture control systems or immersive user interfaces with haptic feedback. PMID:25580901

Depth camera-based 3D hand gesture controls with immersive tactile feedback for natural mid-air gesture interactions.

PubMed

Kim, Kwangtaek; Kim, Joongrock; Choi, Jaesung; Kim, Junghyun; Lee, Sangyoun

2015-01-08

Vision-based hand gesture interactions are natural and intuitive when interacting with computers, since we naturally exploit gestures to communicate with other people. However, it is agreed that users suffer from discomfort and fatigue when using gesture-controlled interfaces, due to the lack of physical feedback. To solve the problem, we propose a novel complete solution of a hand gesture control system employing immersive tactile feedback to the user's hand. For this goal, we first developed a fast and accurate hand-tracking algorithm with a Kinect sensor using the proposed MLBP (modified local binary pattern) that can efficiently analyze 3D shapes in depth images. The superiority of our tracking method was verified in terms of tracking accuracy and speed by comparing with existing methods, Natural Interaction Technology for End-user (NITE), 3D Hand Tracker and CamShift. As the second step, a new tactile feedback technology with a piezoelectric actuator has been developed and integrated into the developed hand tracking algorithm, including the DTW (dynamic time warping) gesture recognition algorithm for a complete solution of an immersive gesture control system. The quantitative and qualitative evaluations of the integrated system were conducted with human subjects, and the results demonstrate that our gesture control with tactile feedback is a promising technology compared to a vision-based gesture control system that has typically no feedback for the user's gesture inputs. Our study provides researchers and designers with informative guidelines to develop more natural gesture control systems or immersive user interfaces with haptic feedback.

Medical, Psychophysiological, and Human Performance Problems During Extended EVA

NASA Technical Reports Server (NTRS)

1997-01-01

In this session, Session JP1, the discussion focuses on the following topics: New Developments in the Assessment of the Risk of Decompression Sickness in Null Gravity During Extravehicular Activity; The Dynamic of Physiological Reactions of Cosmonauts Under the Influence of Repeated EVA Workouts, The Russian Experience; Medical Emergencies in Space; The Evolution from 'Physiological Adequacy' to 'Physiological Tuning'; Five Zones of Symmetrical and Asymmetrical Conflicting Temperatures on the Human Body, Physiological Consequences; Human Performance and Subjective Perception in Nonuniform Thermal Conditions; The Hand as a Control System, Implications for Hand-Finger Dexterity During Extended EVA; and Understanding the Skill of Extravehicular Mass Handling.

Chimpanzees' context-dependent tool use provides evidence for separable representations of hand and tool even during active use within peripersonal space.

PubMed

Povinelli, Daniel J; Reaux, James E; Frey, Scott H

2010-01-01

Considerable attention has been devoted to behaviors in which tools are used to perform actions in extrapersonal space by extending the reach. Evidence suggests that these behaviors result in an expansion of the body schema and peripersonal space. However, humans often use tools to perform tasks within peripersonal space that cannot be accomplished with the hands. In some of these instances (e.g., cooking), a tool is used as a substitute for the hand in order to pursue actions that would otherwise be hazardous. These behaviors suggest that even during the active use of tools, we maintain non-isomorphic representations that distinguish between our hands and handheld tools. Understanding whether such representations are a human specialization is of potentially great relevance to understand the evolutionary history of technological behaviors including the controlled use of fire. We tested six captive adult chimpanzees to determine whether they would elect to use a tool, rather than their hands, when acting in potentially hazardous vs. nonhazardous circumstances located within reach. Their behavior suggests that, like humans, chimpanzees represent the distinction between the hand vs. tool even during active use. We discuss the implications of this evidence for our understanding of tool use and its evolution.

Biomechanical Reconstruction Using the Tacit Learning System: Intuitive Control of Prosthetic Hand Rotation.

PubMed

Oyama, Shintaro; Shimoda, Shingo; Alnajjar, Fady S K; Iwatsuki, Katsuyuki; Hoshiyama, Minoru; Tanaka, Hirotaka; Hirata, Hitoshi

2016-01-01

Background: For mechanically reconstructing human biomechanical function, intuitive proportional control, and robustness to unexpected situations are required. Particularly, creating a functional hand prosthesis is a typical challenge in the reconstruction of lost biomechanical function. Nevertheless, currently available control algorithms are in the development phase. The most advanced algorithms for controlling multifunctional prosthesis are machine learning and pattern recognition of myoelectric signals. Despite the increase in computational speed, these methods cannot avoid the requirement of user consciousness and classified separation errors. "Tacit Learning System" is a simple but novel adaptive control strategy that can self-adapt its posture to environment changes. We introduced the strategy in the prosthesis rotation control to achieve compensatory reduction, as well as evaluated the system and its effects on the user. Methods: We conducted a non-randomized study involving eight prosthesis users to perform a bar relocation task with/without Tacit Learning System support. Hand piece and body motions were recorded continuously with goniometers, videos, and a motion-capture system. Findings: Reduction in the participants' upper extremity rotatory compensation motion was monitored during the relocation task in all participants. The estimated profile of total body energy consumption improved in five out of six participants. Interpretation: Our system rapidly accomplished nearly natural motion without unexpected errors. The Tacit Learning System not only adapts human motions but also enhances the human ability to adapt to the system quickly, while the system amplifies compensation generated by the residual limb. The concept can be extended to various situations for reconstructing lost functions that can be compensated.

Comparative study of state-of-the-art myoelectric controllers for multigrasp prosthetic hands.

PubMed

Segil, Jacob L; Controzzi, Marco; Weir, Richard F ff; Cipriani, Christian

2014-01-01

A myoelectric controller should provide an intuitive and effective human-machine interface that deciphers user intent in real-time and is robust enough to operate in daily life. Many myoelectric control architectures have been developed, including pattern recognition systems, finite state machines, and more recently, postural control schemes. Here, we present a comparative study of two types of finite state machines and a postural control scheme using both virtual and physical assessment procedures with seven nondisabled subjects. The Southampton Hand Assessment Procedure (SHAP) was used in order to compare the effectiveness of the controllers during activities of daily living using a multigrasp artificial hand. Also, a virtual hand posture matching task was used to compare the controllers when reproducing six target postures. The performance when using the postural control scheme was significantly better (p < 0.05) than the finite state machines during the physical assessment when comparing within-subject averages using the SHAP percent difference metric. The virtual assessment results described significantly greater completion rates (97% and 99%) for the finite state machines, but the movement time tended to be faster (2.7 s) for the postural control scheme. Our results substantiate that postural control schemes rival other state-of-the-art myoelectric controllers.

The efficacy of using human myoelectric signals to control the limbs of robots in space

NASA Technical Reports Server (NTRS)

Clark, Jane E.; Phillips, Sally J.

1988-01-01

This project was designed to investigate the usefulness of the myoelectric signal as a control in robotics applications. More specifically, the neural patterns associated with human arm and hand actions were studied to determine the efficacy of using these myoelectric signals to control the manipulator arm of a robot. The advantage of this approach to robotic control was the use of well-defined and well-practiced neural patterns already available to the system, as opposed to requiring the human operator to learn new tasks and establish new neural patterns in learning to control a joystick or mechanical coupling device.

Learned Manipulation at Unconstrained Contacts Does Not Transfer across Hands

PubMed Central

Fu, Qiushi; Choi, Jason Y.; Gordon, Andrew M.; Jesunathadas, Mark; Santello, Marco

2014-01-01

Recent studies about sensorimotor control of the human hand have focused on how dexterous manipulation is learned and generalized. Here we address this question by testing the extent to which learned manipulation can be transferred when the contralateral hand is used and/or object orientation is reversed. We asked subjects to use a precision grip to lift a grip device with an asymmetrical mass distribution while minimizing object roll during lifting by generating a compensatory torque. Subjects were allowed to grasp anywhere on the object’s vertical surfaces, and were therefore able to modulate both digit positions and forces. After every block of eight trials performed in one manipulation context (i.e., using the right hand and at a given object orientation), subjects had to lift the same object in the second context for one trial (transfer trial). Context changes were made by asking subjects to switch the hand used to lift the object and/or rotate the object 180° about a vertical axis. Therefore, three transfer conditions, hand switch (HS), object rotation (OR), and both hand switch and object rotation (HS+OR), were tested and compared with hand matched control groups who did not experience context changes. We found that subjects in all transfer conditions adapted digit positions across multiple transfer trials similar to the learning of control groups, regardless of different changes of contexts. Moreover, subjects in both HS and HS+OR group also adapted digit forces similar to the control group, suggesting independent learning of the left hand. In contrast, the OR group showed significant negative transfer of the compensatory torque due to an inability to adapt digit forces. Our results indicate that internal representations of dexterous manipulation tasks may be primarily built through the hand used for learning and cannot be transferred across hands. PMID:25233091

Design of the NASA Robonaut Hand

NASA Technical Reports Server (NTRS)

Lovchik, Chris S.; Aldridge, H. A.; Driftler, Myron A.

1999-01-01

The design of a highly anthropomorphic human scale robot hand for space based operations is described. This five finger hand combined with its integrated wrist and forearm has fourteen independent degrees of freedom. The device approximates very well the kinematics and required strength of an astronaut's hand when operating through a pressurized space suit glove. The mechanisms used to meet these requirements are explained in detail along with the design philosophy behind them. Integration experiences reveal the challenges associated with obtaining the required capabilities within the desired size. The initial finger control strategy is presented along with examples of obtainable grasps.

Advances in graphonomics: studies on fine motor control, its development and disorders.

PubMed

Van Gemmert, Arend W A; Teulings, Hans-Leo

2006-10-01

During the past 20 years graphonomic research has become a major contributor to the understanding of human movement science. Graphonomic research investigates the relationship between the planning and generation of fine motor tasks, in particular, handwriting and drawing. Scientists in this field are at the forefront of using new paradigms to investigate human movement. The 16 articles in this special issue of Human Movement Science show that the field of graphonomics makes an important contribution to the understanding of fine motor control, motor development, and movement disorders. Topics discussed include writer's cramp, multiple sclerosis, Parkinson's disease, schizophrenia, drug-induced parkinsonism, dopamine depletion, dysgraphia, motor development, developmental coordination disorder, caffeine, alertness, arousal, sleep deprivation, visual feedback transformation and suppression, eye-hand coordination, pen grip, pen pressure, movement fluency, bimanual interference, dominant versus non-dominant hand, tracing, freehand drawing, spiral drawing, reading, typewriting, and automatic segmentation.

Engaging cervical spinal cord networks to re-enable volitional control of hand function in tetraplegic patients

PubMed Central

Lu, Daniel C.; Edgerton, V. Reggie; Modaber, Morteza; AuYong, Nicholas; Morikawa, Erika; Zdunowski, Sharon; Sarino, Melanie E.; Nuwer, Marc R.; Roy, Roland R.; Gerasimenko, Yury

2016-01-01

Background Paralysis of the upper-limbs from spinal cord injury results in an enormous loss of independence in an individual’s daily life. Meaningful improvement in hand function is rare after one year of tetraparesis. Therapeutic developments that result in even modest gains in hand volitional function will significantly impact the quality of life for patients afflicted with high cervical injury. The ability to neuromodulate the lumbosacral spinal circuitry via epidural stimulation in regaining postural function and volitional control of the legs has been recently shown. A key question is whether a similar neuromodulatory strategy can be used to improve volitional motor control of the upper-limbs, i.e., performance of motor tasks considered to be less “automatic” than posture and locomotion. In this study, the effects of cervical epidural stimulation on hand function are characterized in subjects with chronic cervical cord injury. Objective Herein we show that epidural stimulation can be applied to the chronic injured human cervical spinal cord to promote volitional hand function. Methods and results Two subjects implanted with an cervical epidural electrode array demonstrated improved hand strength (approximately three-fold) and volitional hand control in the presence of epidural stimulation. Conclusions The present data are sufficient to suggest that hand motor function in individuals with chronic tetraplegia can be improved with cervical cord neuromodulation and thus should be comprehensively explored as a possible clinical intervention. PMID:27198185

Synchronizing movements with the metronome: nonlinear error correction and unstable periodic orbits.

PubMed

Engbert, Ralf; Krampe, Ralf Th; Kurths, Jürgen; Kliegl, Reinhold

2002-02-01

The control of human hand movements is investigated in a simple synchronization task. We propose and analyze a stochastic model based on nonlinear error correction; a mechanism which implies the existence of unstable periodic orbits. This prediction is tested in an experiment with human subjects. We find that our experimental data are in good agreement with numerical simulations of our theoretical model. These results suggest that feedback control of the human motor systems shows nonlinear behavior. Copyright 2001 Elsevier Science (USA).

Predictability, Force and (Anti-)Resonance in Complex Object Control.

PubMed

Maurice, Pauline; Hogan, Neville; Sternad, Dagmar

2018-04-18

Manipulation of complex objects as in tool use is ubiquitous and has given humans an evolutionary advantage. This study examined the strategies humans choose when manipulating an object with underactuated internal dynamics, such as a cup of coffee. The object's dynamics renders the temporal evolution complex, possibly even chaotic, and difficult to predict. A cart-and-pendulum model, loosely mimicking coffee sloshing in a cup, was implemented in a virtual environment with a haptic interface. Participants rhythmically manipulated the virtual cup containing a rolling ball; they could choose the oscillation frequency, while the amplitude was prescribed. Three hypotheses were tested: 1) humans decrease interaction forces between hand and object; 2) humans increase the predictability of the object dynamics; 3) humans exploit the resonances of the coupled object-hand system. Analysis revealed that humans chose either a high-frequency strategy with anti-phase cup-and-ball movements or a low-frequency strategy with in-phase cup-and-ball movements. Counter Hypothesis 1, they did not decrease interaction force; instead, they increased the predictability of the interaction dynamics, quantified by mutual information, supporting Hypothesis 2. To address Hypothesis 3, frequency analysis of the coupled hand-object system revealed two resonance frequencies separated by an anti-resonance frequency. The low-frequency strategy exploited one resonance, while the high-frequency strategy afforded more choice, consistent with the frequency response of the coupled system; both strategies avoided the anti-resonance. Hence, humans did not prioritize interaction force, but rather strategies that rendered interactions predictable. These findings highlight that physical interactions with complex objects pose control challenges not present in unconstrained movements.

A Tactile Stimulator for Studying Passive Shape Perception

PubMed Central

Lane, John W.; Fitzgerald, Paul J.; Yau, Jeffrey M.; Pembeci, Izzet; Hsiao, Steven S.

2009-01-01

We describe a computer-controlled tactile stimulator for use in human psychophysical and monkey neurophysiological studies of 3-D shape perception. The stimulator is constructed primarily of commercially available parts, as well as a few custom-built pieces for which we will supply diagrams upon request. There are two components to the stimulator: a tactile component and a hand positioner component. The tactile component consists of multiple stimulating units that move about in a Cartesian plane above the restrained hand. Each stimulating unit contains a servo-controlled linear motor with an attached small rotary stepper motor, allowing arbitrary stimulus shapes to contact the skin through vibration, static indentation, or scanning. The hand positioner component modifies the conformation of the restrained hand through a set of mechanical linkages under motorized control. The present design controls the amount of spread between digits two and three, the spread between digits four and three, and the degree to which digit three is flexed or extended, thereby simulating different conformations of the hand in contact with objects. This design is easily modified to suit the needs of the experimenter. Because the two components of the stimulator are independently controlled, the stimulator allows for parametric study of the mechanoreceptive and proprioceptive contributions to 3-D tactile shape perception. PMID:19800916

Learning in robotic manipulation: The role of dimensionality reduction in policy search methods. Comment on "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

NASA Astrophysics Data System (ADS)

Ficuciello, Fanny; Siciliano, Bruno

2016-07-01

A question that often arises, among researchers working on artificial hands and robotic manipulation, concerns the real meaning of synergies. Namely, are they a realistic representation of the central nervous system control of manipulation activities at different levels and of the sensory-motor manipulation apparatus of the human being, or do they constitute just a theoretical framework exploiting analytical methods to simplify the representation of grasping and manipulation activities? Apparently, this is not a simple question to answer and, in this regard, many minds from the field of neuroscience and robotics are addressing the issue [1]. The interest of robotics is definitely oriented towards the adoption of synergies to tackle the control problem of devices with high number of degrees of freedom (DoFs) which are required to achieve motor and learning skills comparable to those of humans. The synergy concept is useful for innovative underactuated design of anthropomorphic hands [2], while the resulting dimensionality reduction simplifies the control of biomedical devices such as myoelectric hand prostheses [3]. Synergies might also be useful in conjunction with the learning process [4]. This aspect is less explored since few works on synergy-based learning have been realized in robotics. In learning new tasks through trial-and-error, physical interaction is important. On the other hand, advanced mechanical designs such as tendon-driven actuation, underactuated compliant mechanisms and hyper-redundant/continuum robots might exhibit enhanced capabilities of adapting to changing environments and learning from exploration. In particular, high DoFs and compliance increase the complexity of modelling and control of these devices. An analytical approach to manipulation planning requires a precise model of the object, an accurate description of the task, and an evaluation of the object affordance, which all make the process rather time consuming. The integration of learning into control naturally leads to relaxing the above requirements through the adoption of coordinated motion patterns and sensory-motor synergies as useful tools leading to a problem of reduced dimension. To this purpose, model-based control strategies relying on synergistic models of manipulation activities learned from human experience can be integrated with real-time learning from actions strategies [5]. In [6] a classification of learning strategies for robotics is provided, while the difference between imitation learning and reinforcement learning (RL) is highlighted in [7]. From recent research in the field [8,9], it seems that RL represents the future toward autonomous and intelligent robots since it provides learning capabilities as those of humans, i.e. based on exploration and trial-and-error policies. In this context, suitable policy search methods to be implemented in a synergy-based framework are to be sought in order to reduce the search space dimension while guaranteeing the convergence and efficiency of the learning algorithm.

Assessment of Myoelectric Controller Performance and Kinematic Behavior of a Novel Soft Synergy-Inspired Robotic Hand for Prosthetic Applications

PubMed Central

Fani, Simone; Bianchi, Matteo; Jain, Sonal; Pimenta Neto, José Simões; Boege, Scott; Grioli, Giorgio; Bicchi, Antonio; Santello, Marco

2016-01-01

Myoelectric artificial limbs can significantly advance the state of the art in prosthetics, since they can be used to control mechatronic devices through muscular activity in a way that mimics how the subjects used to activate their muscles before limb loss. However, surveys indicate that dissatisfaction with the functionality of terminal devices underlies the widespread abandonment of prostheses. We believe that one key factor to improve acceptability of prosthetic devices is to attain human likeness of prosthesis movements, a goal which is being pursued by research on social and human–robot interactions. Therefore, to reduce early abandonment of terminal devices, we propose that controllers should be designed so as to ensure effective task accomplishment in a natural fashion. In this work, we have analyzed and compared the performance of three types of myoelectric controller algorithms based on surface electromyography to control an underactuated and multi-degrees of freedom prosthetic hand, the SoftHand Pro. The goal of the present study was to identify the myoelectric algorithm that best mimics the native hand movements. As a preliminary step, we first quantified the repeatability of the SoftHand Pro finger movements and identified the electromyographic recording sites for able-bodied individuals with the highest signal-to-noise ratio from two pairs of muscles, i.e., flexor digitorum superficialis/extensor digitorum communis, and flexor carpi radialis/extensor carpi ulnaris. Able-bodied volunteers were then asked to execute reach-to-grasp movements, while electromyography signals were recorded from flexor digitorum superficialis/extensor digitorum communis as this was identified as the muscle pair characterized by high signal-to-noise ratio and intuitive control. Subsequently, we tested three myoelectric controllers that mapped electromyography signals to position of the SoftHand Pro. We found that a differential electromyography-to-position mapping ensured the highest coherence with hand movements. Our results represent a first step toward a more effective and intuitive control of myoelectric hand prostheses. PMID:27799908

Diffuse noxious inhibitory control. Reappraisal by pain-related somatosensory evoked potentials following CO2 laser stimulation.

PubMed

Kakigi, R

1994-09-01

The effects of DNIC (diffuse noxious inhibitory control) in humans were evaluated by means of pain SEPs (somatosensory evoked potentials) and pain visual analogue scale (VAS) following CO2 laser stimulation applied to the left knee while conditioning stimuli (non-noxious and noxious thermal stimuli) applied to the right hand. Pain SEPs were recorded from scalp electrodes following laser stimulation applied to the left knee during various conditions as follows: (1) control (without any interference), (2) non-noxious (dipping the right hand in water at 41 degrees C for 3 min), (3) noxious (dipping the right hand in water at 46 degrees C for 3 min), and (4) after-effect (3-6 min after taking the hand from the water at 46 degrees C). The present pain SEPs findings confirmed the presence of DNIC in humans, and indicates: (1) degree of pain relief was significantly correlated with changes in pain SEPs, particularly a marked decrease in amplitude, and a decrease in VAS; (2) DNIC was more effective on the second pain than the first pain; (3) the effect of DNIC gradually increased over time, but it rapidly disappeared after the conditioning stimuli ceased; and (4) DNIC was not due merely to changes of attention. I propose that the site responsible for DNIC is the brainstem or the spinal cord rather than the cerebral hemisphere.

Evidence from intrinsic activity that asymmetry of the human brain is controlled by multiple factors.

PubMed

Liu, Hesheng; Stufflebeam, Steven M; Sepulcre, Jorge; Hedden, Trey; Buckner, Randy L

2009-12-01

Cerebral lateralization is a fundamental property of the human brain and a marker of successful development. Here we provide evidence that multiple mechanisms control asymmetry for distinct brain systems. Using intrinsic activity to measure asymmetry in 300 adults, we mapped the most strongly lateralized brain regions. Both men and women showed strong asymmetries with a significant, but small, group difference. Factor analysis on the asymmetric regions revealed 4 separate factors that each accounted for significant variation across subjects. The factors were associated with brain systems involved in vision, internal thought (the default network), attention, and language. An independent sample of right- and left-handed individuals showed that hand dominance affects brain asymmetry but differentially across the 4 factors supporting their independence. These findings show the feasibility of measuring brain asymmetry using intrinsic activity fluctuations and suggest that multiple genetic or environmental mechanisms control cerebral lateralization.

Handwashing: a simple, economical and effective method for preventing nosocomial infections in intensive care units.

PubMed

Akyol, A; Ulusoy, H; Ozen, I

2006-04-01

As most nosocomial infections are thought to be transmitted by the hands of healthcare workers, handwashing is considered to be the single most important intervention to prevent nosocomial infections. However, studies have shown that handwashing practices are poor, especially among medical personnel. This review gives an overview of handwashing in health care and in the community, including some aspects that have attracted little attention, such as hand drying and cultural issues determining hand hygiene behaviour. Hand hygiene is the most effective measure for interrupting the transmission of micro-organisms which cause infection, both in the community and in the healthcare setting. Using hand hygiene as a sole measure to reduce infection is unlikely to be successful when other factors in infection control, such as environmental hygiene, crowding, staffing levels and education, are inadequate. Hand hygiene must be part of an integrated approach to infection control. Compliance with hand hygiene recommendations is poor worldwide. While the techniques involved in hand hygiene are simple, the complex interdependence of factors that determine hand hygiene behaviour makes the study of hand hygiene complex. It is now recognized that improving compliance with hand hygiene recommendations depends on altering human behaviour. Input from behavioural and social sciences is essential when designing studies to investigate compliance. Interventions to increase compliance with hand hygiene practices must be appropriate for different cultural and social needs.

Short- and Long-Term Effects of Unpredictable Repeated Negative Stimuli on Japanese Quail's Fear of Humans

PubMed Central

Laurence, Agathe; Lumineau, Sophie; Calandreau, Ludovic; Arnould, Cécile; Leterrier, Christine; Boissy, Alain; Houdelier, Cécilia

2014-01-01

Numerous aversive events occur in poultry production, and if repeated and unpredictable, can result in an impaired welfare. Some events such as handling can be perceived negatively and it is of interest to understand how humans' behaviour could affect poultry's behaviours and especially its avoidance of humans. Our aim was to evaluate short- and long-lasting effects of a 3-week procedure involving unpredictable repeated negative stimuli (URNS) applied during the post-juvenile period on quail's reactivity to humans. We compared the reactions of two sets of quail: URNS was applied to one set (treated quail) and the other set was left undisturbed (control quail). When two weeks old, treated quail were exposed to a variety of negative stimuli, either applied automatically or involving human presence. One and seven weeks after the termination of the procedure, the reactivity of control and treated quail to a passive human being was evaluated. Furthermore, the experimenter with her hand on a trough containing a mealworm assessed the propensity of quail of both groups to habituate to feed close to a human being. In the presence of a seated observer, treated quail were more inhibited and more alert than control quail. Likewise, seven weeks after the end of the URNS procedure, more treated than control quail adopted a fear posture. Moreover, whereas control quail spent as much time in the different areas of their cages, treated quail spent more time in the rear part of their cages. Finally, whereas control quail habituated gradually to feed near the experimenter's hand, treated quail did not. All these tests evidence negative short- and long-term effects on treated quail's reactivity to a passive human being and on their habituation to a human being when her presence is positively reinforced. This highlights the importance of young poultry's experience with humans in production. PMID:24668017

Neuronal ensemble control of prosthetic devices by a human with tetraplegia

NASA Astrophysics Data System (ADS)

Hochberg, Leigh R.; Serruya, Mijail D.; Friehs, Gerhard M.; Mukand, Jon A.; Saleh, Maryam; Caplan, Abraham H.; Branner, Almut; Chen, David; Penn, Richard D.; Donoghue, John P.

2006-07-01

Neuromotor prostheses (NMPs) aim to replace or restore lost motor functions in paralysed humans by routeing movement-related signals from the brain, around damaged parts of the nervous system, to external effectors. To translate preclinical results from intact animals to a clinically useful NMP, movement signals must persist in cortex after spinal cord injury and be engaged by movement intent when sensory inputs and limb movement are long absent. Furthermore, NMPs would require that intention-driven neuronal activity be converted into a control signal that enables useful tasks. Here we show initial results for a tetraplegic human (MN) using a pilot NMP. Neuronal ensemble activity recorded through a 96-microelectrode array implanted in primary motor cortex demonstrated that intended hand motion modulates cortical spiking patterns three years after spinal cord injury. Decoders were created, providing a `neural cursor' with which MN opened simulated e-mail and operated devices such as a television, even while conversing. Furthermore, MN used neural control to open and close a prosthetic hand, and perform rudimentary actions with a multi-jointed robotic arm. These early results suggest that NMPs based upon intracortical neuronal ensemble spiking activity could provide a valuable new neurotechnology to restore independence for humans with paralysis.

Human Performance in Space

NASA Technical Reports Server (NTRS)

Jones, Patricia M.; Fiedler, Edna

2010-01-01

Human factors is a critical discipline for human spaceflight. Nearly every human factors research area is relevant to space exploration -- from the ergonomics of hand tools used by astronauts, to the displays and controls of a spacecraft cockpit or mission control workstation, to levels of automation designed into rovers on Mars, to organizational issues of communication between crew and ground. This chapter focuses more on the ways in which the space environment (especially altered gravity and the isolated and confined nature of long-duration spaceflight) affects crew performance, and thus has specific novel implications for human factors research and practice. We focus on four aspects of human performance: neurovestibular integration, motor control and musculo-skeletal effects, cognitive effects, and behavioral health. We also provide a sampler of recent human factors studies from NASA.

The Neural Correlates of Grasping in Left-Handers: When Handedness Does Not Matter.

PubMed

Begliomini, Chiara; Sartori, Luisa; Di Bono, Maria G; Budisavljević, Sanja; Castiello, Umberto

2018-01-01

Neurophysiological studies showed that in macaques, grasp-related visuomotor transformations are supported by a circuit involving the anterior part of the intraparietal sulcus, the ventral and the dorsal region of the premotor area. In humans, a similar grasp-related circuit has been revealed by means of neuroimaging techniques. However, the majority of "human" studies considered movements performed by right-handers only, leaving open the question of whether the dynamics underlying motor control during grasping is simply reversed in left-handers with respect to right-handers or not. To address this question, a group of left-handed participants has been scanned with functional magnetic resonance imaging while performing a precision grasping task with the left or the right hand. Dynamic causal modeling was used to assess how brain regions of the two hemispheres contribute to grasping execution and whether the intra- and inter-hemispheric connectivity is modulated by the choice of the performing hand. Results showed enhanced inter-hemispheric connectivity between anterior intraparietal and dorsal premotor cortices during grasping execution with the left dominant hand (LDH) (e.g., right hemisphere) compared to the right (e.g., left hemisphere). These findings suggest that that the left hand, although dominant and theoretically more skilled in left handers, might need additional resources in terms of the visuomotor control and on-line monitoring to accomplish a precision grasping movement. The results are discussed in light of theories on the modulation of parieto-frontal networks during the execution of prehensile movements, providing novel evidence supporting the hypothesis of a handedness-independent specialization of the left hemisphere in visuomotor control.

System description document for the Anthrobot-2: A dexterous robot hand

NASA Technical Reports Server (NTRS)

Ali, Michael S.; Engler, Charles, Jr.

1991-01-01

The Anthrobot-2 is an anatomically correct, fully functioning robot hand. The number of fingers, the proportions of the links, the placement and motion of the thumb, and the shape of the palm follow those of the human hand. Each of the finger and thumb joints are servo-controlled. The Anthrobot-2 also includes a two-degree-of-freedom wrist. The entire package, including wrist, hand, and actuators, will mount on the ends of a variety of industrial manipulators. A patent has been applied for on the design. The Anthrobot-2 will be useful in tasks where dexterous manipulation or telemanipulation are required.

Intermittently-visual Tracking Experiments Reveal the Roles of Error-correction and Predictive Mechanisms in the Human Visual-motor Control System

NASA Astrophysics Data System (ADS)

Hayashi, Yoshikatsu; Tamura, Yurie; Sase, Kazuya; Sugawara, Ken; Sawada, Yasuji

Prediction mechanism is necessary for human visual motion to compensate a delay of sensory-motor system. In a previous study, “proactive control” was discussed as one example of predictive function of human beings, in which motion of hands preceded the virtual moving target in visual tracking experiments. To study the roles of the positional-error correction mechanism and the prediction mechanism, we carried out an intermittently-visual tracking experiment where a circular orbit is segmented into the target-visible regions and the target-invisible regions. Main results found in this research were following. A rhythmic component appeared in the tracer velocity when the target velocity was relatively high. The period of the rhythm in the brain obtained from environmental stimuli is shortened more than 10%. The shortening of the period of rhythm in the brain accelerates the hand motion as soon as the visual information is cut-off, and causes the precedence of hand motion to the target motion. Although the precedence of the hand in the blind region is reset by the environmental information when the target enters the visible region, the hand motion precedes the target in average when the predictive mechanism dominates the error-corrective mechanism.

Tobacco smoking and hand eczema - is there an association?

PubMed

Sørensen, Jennifer A; Clemmensen, Kim K; Nixon, Rosemary L; Diepgen, Thomas L; Agner, Tove

2015-12-01

Numerous risk factors have been suggested for hand eczema. This systematic review evaluates the association between tobacco smoking and hand eczema. To review the literature systematically on the association between smoking and hand eczema. The PubMed and EMBASE databases were searched up to 27 January 2015 for articles on the association between tobacco smoking and hand eczema, including human studies in English and German only. Experimental studies, studies on tobacco allergy, case reports, reviews and studies on second-hand smoking were excluded. Twenty articles were included. Among studies in occupational settings, three of seven found a statistically significant positive association between tobacco smoking and hand eczema prevalence rate, as did four of eight population-based studies. The association was stronger for studies in occupational settings than for population-based studies. No studies reported tobacco to be a clear protective factor for hand eczema. Two of five studies regarding severity found a positive association between smoking and hand eczema severity. Overall, the data indicate that smoking may cause an increased frequency of hand eczema, particularly in high-risk occupations. However, data from studies controlling for other risk factors are conflicting, and few prospective studies are available. Studies controlling for other risk factors are needed, and information regarding the diagnosis of subclasses of hand eczema, as well as severity, may be important. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Single DoF Hand Orthosis for Rehabilitation of Stroke and SCI Patients

NASA Astrophysics Data System (ADS)

Kannan Megalingam, Rajesh; Apuroop, K. G. S.; Boddupalli, Sricharan

2017-08-01

Many stroke and spinal cord injury patients suffer from paralysis which range from severe to nominal. Some of them, after therapy, could regain most of the motor control, particularly in hands if the severity level is not so high. In this paper we propose a hand orthosis for such patients whose stroke and spinal cord injury severity is nominal and the motor control in hands can be regained by therapy as part of their rehabilitation process. The patients can wear this orthosis and the therapy can be done with simple Human Computer Interface. The physicians, the physiotherapists and the patients themselves can carry out the therapy with the help of this device. The tests conducted in the lab and the results obtained are very promising that this can be an effective mechanism for stroke and spinal cord injury patients in their rehabilitation process. The hand orthosis is designed and fabricated locally so that it can be made available to such patients at an affordable cost.

Assessing the manipulative potentials of monkeys, apes and humans from hand proportions: implications for hand evolution.

PubMed

Liu, Ming-Jin; Xiong, Cai-Hua; Hu, Di

2016-11-30

The hand structure possesses a greater potential for performing manipulative skills than is typically observed, whether in humans or non-human anthropoids. However, a precise assessment of the potential manipulative skills of hands has been challenging, which hampers our understanding of the evolution of manipulative abilities in anthropoid hands. Here, we establish a functional model to quantitatively infer the manipulative potentials of anthropoid hands based on hand proportions. Our results reveal a large disparity of manipulative potentials among anthropoid hands. From the aspect of hand proportions, the human hand has the best manipulative potential among anthropoids. However, the species with a manipulative potential closer to that of humans are not our nearest relatives, chimpanzees, but rather, are certain monkey species. In combination with the phylogenetically informed morphometric analyses, our results suggest that the morphological changes of non-human anthropoid hands did not coevolve with the brain to facilitate the manipulative ability during the evolutionary process, although the manipulative ability is a survival skill. The changes in non-human anthropoid hands may have more likely evolved under selective pressure for locomotion than manipulation. © 2016 The Author(s).

An Interactive Astronaut-Robot System with Gesture Control

PubMed Central

Liu, Jinguo; Luo, Yifan; Ju, Zhaojie

2016-01-01

Human-robot interaction (HRI) plays an important role in future planetary exploration mission, where astronauts with extravehicular activities (EVA) have to communicate with robot assistants by speech-type or gesture-type user interfaces embedded in their space suits. This paper presents an interactive astronaut-robot system integrating a data-glove with a space suit for the astronaut to use hand gestures to control a snake-like robot. Support vector machine (SVM) is employed to recognize hand gestures and particle swarm optimization (PSO) algorithm is used to optimize the parameters of SVM to further improve its recognition accuracy. Various hand gestures from American Sign Language (ASL) have been selected and used to test and validate the performance of the proposed system. PMID:27190503

Bio-inspired grasp control in a robotic hand with massive sensorial input.

PubMed

Ascari, Luca; Bertocchi, Ulisse; Corradi, Paolo; Laschi, Cecilia; Dario, Paolo

2009-02-01

The capability of grasping and lifting an object in a suitable, stable and controlled way is an outstanding feature for a robot, and thus far, one of the major problems to be solved in robotics. No robotic tools able to perform an advanced control of the grasp as, for instance, the human hand does, have been demonstrated to date. Due to its capital importance in science and in many applications, namely from biomedics to manufacturing, the issue has been matter of deep scientific investigations in both the field of neurophysiology and robotics. While the former is contributing with a profound understanding of the dynamics of real-time control of the slippage and grasp force in the human hand, the latter tries more and more to reproduce, or take inspiration by, the nature's approach, by means of hardware and software technology. On this regard, one of the major constraints robotics has to overcome is the real-time processing of a large amounts of data generated by the tactile sensors while grasping, which poses serious problems to the available computational power. In this paper a bio-inspired approach to tactile data processing has been followed in order to design and test a hardware-software robotic architecture that works on the parallel processing of a large amount of tactile sensing signals. The working principle of the architecture bases on the cellular nonlinear/neural network (CNN) paradigm, while using both hand shape and spatial-temporal features obtained from an array of microfabricated force sensors, in order to control the sensory-motor coordination of the robotic system. Prototypical grasping tasks were selected to measure the system performances applied to a computer-interfaced robotic hand. Successful grasps of several objects, completely unknown to the robot, e.g. soft and deformable objects like plastic bottles, soft balls, and Japanese tofu, have been demonstrated.

Illusory sense of human touch from a warm and soft artificial hand.

PubMed

Cabibihan, John-John; Joshi, Deepak; Srinivasa, Yeshwin Mysore; Chan, Mark Aaron; Muruganantham, Arrchana

2015-05-01

To touch and be touched are vital to human development, well-being, and relationships. However, to those who have lost their arms and hands due to accident or war, touching becomes a serious concern that often leads to psychosocial issues and social stigma. In this paper, we demonstrate that the touch from a warm and soft rubber hand can be perceived by another person as if the touch were coming from a human hand. We describe a three-step process toward this goal. First, we made participants select artificial skin samples according to their preferred warmth and softness characteristics. At room temperature, the preferred warmth was found to be 28.4 °C at the skin surface of a soft silicone rubber material that has a Shore durometer value of 30 at the OO scale. Second, we developed a process to create a rubber hand replica of a human hand. To compare the skin softness of a human hand and artificial hands, a robotic indenter was employed to produce a softness map by recording the displacement data when constant indentation force of 1 N was applied to 780 data points on the palmar side of the hand. Results showed that an artificial hand with skeletal structure is as soft as a human hand. Lastly, the participants' arms were touched with human and artificial hands, but they were prevented from seeing the hand that touched them. Receiver operating characteristic curve analysis suggests that a warm and soft artificial hand can create an illusion that the touch is from a human hand. These findings open the possibilities for prosthetic and robotic hands that are life-like and are more socially acceptable.

EXOS research on force-reflecting controllers

NASA Astrophysics Data System (ADS)

Eberman, Brian S.; An, Bin

1993-03-01

EXOS has developed two state of the art prototype master controllers for controlling robot hands and manipulators under the Small Business Innovation Research (SBIR) program with NASA. One such device is a two degree-of-freedom Sensing and Force Reflecting Exoskeleton (SAFiRE) worn on the operator's hand. The device measures the movement of the index finger and reflects the interaction forces between the slave robot and the environment to the human finger. The second device is a position sensing Exoskeleton ArmMaster (EAM) worn by a human operator. The device simultaneously tracks the motions of the operator's three DOF shoulder and two DOF elbow. Both of these devices are currently used to control robots at NASA. We are currently developing a full fingered SAFiRE and a position sensing and force reflecting EAM under two second phase SBIR grants with NASA. This paper will include discussions of: (1) the design of the current prototypes, (2) kinematics of the EAM and force control of the SAFiRE, (3) design issues that must be addressed in developing more advanced versions, and (4) our progress to date in addressing these issues.

The WCSAR telerobotics test bed

NASA Technical Reports Server (NTRS)

Duffie, N.; Zik, J.; Teeter, R.; Crabb, T.

1988-01-01

Component technologies for use in telerobotic systems for space are being developed. As part of this effort, a test bed was established in which these technologies can be verified and integrated into telerobotic systems. The facility consists of two slave industrial robots, an articulated master arm controller, a cartesian coordinate master arm controller, and a variety of sensors, displays and stimulators for feedback to human operators. The controller of one of the slave robots remains in its commercial state, while the controller of the other robot has been replaced with a new controller that achieves high-performance in telerobotic operating modes. A dexterous slave hand which consists of two fingers and a thumb is being developed, along with a number of force-reflecting and non-force reflecting master hands, wrists and arms. A tactile sensing finger tip based on piezo-film technology has been developed, along with tactile stimulators and CAD-based displays for sensory feedback and sensory substitution. The telerobotics test bed and its component technologies are described, as well as the integration of these component technologies into telerobotic systems, and their performance in conjunction with human operators.

[Development of alternative to animal experiment in evaluation of skin irritation caused by alcohol-based hand rubs].

PubMed

Yamamoto, Nobuyuki; Miyamoto, Koji; Katoh, Masakazu

2010-08-01

Alcohol-based hand rubs are widely used for infection control in clinical practice. However, it is known that frequent use of the alcohol-based hand rubs may cause skin irritation. To predict the skin irritation in human, animal experiments are quite useful. Especially, the Draize Test using rabbits is suitable for this purpose because their skin is highly sensitive. On the other hand, the development of alternative to animal experiments is important not only from the viewpoint of ethical aspects but also from the efficient research and development. Reconstructed human epidermis (RhE) was developed as a human skin equivalent model in vitro, and has been applied to the evaluation of skin irritation. But the RhE has not been utilized for the evaluation of alcohol-based hand rubs because of the high skin permeability and cytotoxicity of alcohols. The aim of this study was to develop a new method using the RhE in evaluation of skin irritation caused by alcohol-based hand rubs. The authors propose an experimental technique named "Skin model blowing method (SMBM)" consisting of the sequential procedure as follows; applying small amount of testing sample on RhE, blow-dry, post incubation, and cell viability measurement. According to the SMBM, the skin irritation caused by alcohol-based hand rubs could be evaluated under the similar condition of their actual use. It was found that a high correlation existed between the cell viability obtained from SMBM and the skin irritation index in rabbit which had been reported previously.

Unreal Interactive Puppet Game Development Using Leap Motion

NASA Astrophysics Data System (ADS)

Huang, An-Pin; Huang, Fay; Jhu, Jing-Siang

2018-04-01

This paper proposed a novel puppet play method utilizing recent technology. An interactive puppet game has been developed based on the theme of a famous Chinese classical novel. This project was implemented using Unreal Engine, which is a leading software of integrated tools for developers to design and build games. On the other hand, Leap Motion Controller is a sensor device for recognizing hand movements and gestures. It is commonly used in systems which require close-range finger-based user interaction. In order to manipulate puppets’ movements, the developed program employs the Leap Motion SDK, which provides a friendly way to add motion-controlled 3D hands to an Unreal game. The novelty of our project is to replace 3D model of rigged hands by two 3D humanoid rigged characters. The challenges of this task are two folds. First, the skeleton structure of a human hand and a humanoid character (i.e., puppets) are totally different. Making the puppets to follow the hand poses of the user and yet ensuring reasonable puppets’ movements has not been discussed in the literatures nor in the developer forums. Second, there are only a limited number of built-in recognizable hand gestures. More recognizable hand gestures need to be created for the interactive game. This paper reports the proposed solutions to these challenges.

Anodal Cerebellar Direct Current Stimulation Reduces Facilitation of Propriospinal Neurons in Healthy Humans.

PubMed

Chothia, Muhammed; Doeltgen, Sebastian; Bradnam, Lynley V

2016-01-01

Coordinated muscle synergies in the human upper limb are controlled, in part, by a neural distribution network located in the cervical spinal cord, known as the cervical propriospinal system. Studies in the cat and non-human primate indicate the cerebellum is indirectly connected to this system via output pathways to the brainstem. Therefore, the cerebellum may indirectly modulate excitability of putative propriospinal neurons (PNs) in humans during upper limb coordination tasks. This study aimed to test whether anodal direct current stimulation (DCS) of the cerebellum modulates PNs and upper limb coordination in healthy adults. The hypothesis was that cerebellar anodal DCS would reduce descending facilitation of PNs and improve upper limb coordination. Transcranial magnetic stimulation (TMS), paired with peripheral nerve stimulation, probed activity in facilitatory and inhibitory descending projections to PNs following an established protocol. Coordination was tested using a pursuit rotor task performed by the non-dominant (ipsilateral) hand. Anodal and sham DCS were delivered over the cerebellum ipsilateral to the non-dominant hand in separate experimental sessions. Anodal DCS was applied to a control site lateral to the vertex in a third session. Twelve right-handed healthy adults participated. Pairing TMS with sub-threshold peripheral nerve stimulation facilitated motor evoked potentials at intensities just above threshold in accordance with the protocol. Anodal cerebellar DCS reduced facilitation without influencing inhibition, but the reduction in facilitation was not associated with performance of the pursuit rotor task. The results of this study indicate dissociated indirect control over cervical PNs by the cerebellum in humans. Anodal DCS of the cerebellum reduced excitability in the facilitatory descending pathway with no effect on the inhibitory pathway to cervical PNs. The reduction in PN excitability is likely secondary to modulation of primary motor cortex or brainstem nuclei, and identifies a neuroanatomical pathway for the cerebellum to assist in coordination of upper limb muscle synergies in humans. Copyright © 2016 Elsevier Inc. All rights reserved.

Learning and Control Model of the Arm for Loading

NASA Astrophysics Data System (ADS)

Kim, Kyoungsik; Kambara, Hiroyuki; Shin, Duk; Koike, Yasuharu

We propose a learning and control model of the arm for a loading task in which an object is loaded onto one hand with the other hand, in the sagittal plane. Postural control during object interactions provides important points to motor control theories in terms of how humans handle dynamics changes and use the information of prediction and sensory feedback. For the learning and control model, we coupled a feedback-error-learning scheme with an Actor-Critic method used as a feedback controller. To overcome sensory delays, a feedforward dynamics model (FDM) was used in the sensory feedback path. We tested the proposed model in simulation using a two-joint arm with six muscles, each with time delays in muscle force generation. By applying the proposed model to the loading task, we showed that motor commands started increasing, before an object was loaded on, to stabilize arm posture. We also found that the FDM contributes to the stabilization by predicting how the hand changes based on contexts of the object and efferent signals. For comparison with other computational models, we present the simulation results of a minimum-variance model.

MicroRNA-363 negatively regulates the left ventricular determining transcription factor HAND1 in human embryonic stem cell-derived cardiomyocytes.

PubMed

Wagh, Vilas; Pomorski, Alexander; Wilschut, Karlijn J; Piombo, Sebastian; Bernstein, Harold S

2014-06-06

Posttranscriptional control of mRNA by microRNA (miRNA) has been implicated in the regulation of diverse biologic processes from directed differentiation of stem cells through organism development. We describe a unique pathway by which miRNA regulates the specialized differentiation of cardiomyocyte (CM) subtypes. We differentiated human embryonic stem cells (hESCs) to cardiac progenitor cells and functional CMs, and characterized the regulated expression of specific miRNAs that target transcriptional regulators of left/right ventricular-subtype specification. From >900 known human miRNAs in hESC-derived cardiac progenitor cells and functional CMs, a subset of differentially expressed cardiac miRNAs was identified, and in silico analysis predicted highly conserved binding sites in the 3'-untranslated regions (3'UTRs) of Hand-and-neural-crest-derivative-expressed (HAND) genes 1 and 2 that are involved in left and right ventricular development. We studied the temporal and spatial expression patterns of four miRNAs in differentiating hESCs, and found that expression of miRNA (miR)-363, miR-367, miR-181a, and miR-181c was specific for stage and site. Further analysis showed that miR-363 overexpression resulted in downregulation of HAND1 mRNA and protein levels. A dual luciferase reporter assay demonstrated functional interaction of miR-363 with the full-length 3'UTR of HAND1. Expression of anti-miR-363 in-vitro resulted in enrichment for HAND1-expressing CM subtype populations. We also showed that BMP4 treatment induced the expression of HAND2 with less effect on HAND1, whereas miR-363 overexpression selectively inhibited HAND1. These data show that miR-363 negatively regulates the expression of HAND1 and suggest that suppression of miR-363 could provide a novel strategy for generating functional left-ventricular CMs.

Development of an Implantable Myoelectric Sensor for Advanced Prosthesis Control

PubMed Central

Merrill, Daniel R.; Lockhart, Joseph; Troyk, Phil R.; Weir, Richard F.; Hankin, David L.

2013-01-01

Modern hand and wrist prostheses afford a high level of mechanical sophistication, but the ability to control them in an intuitive and repeatable manner lags. Commercially available systems using surface electromyographic (EMG) or myoelectric control can supply at best two degrees of freedom (DOF), most often sequentially controlled. This limitation is partially due to the nature of surface-recorded EMG, for which the signal contains components from multiple muscle sources. We report here on the development of an implantable myoelectric sensor using EMG sensors that can be chronically implanted into an amputee’s residual muscles. Because sensing occurs at the source of muscle contraction, a single principal component of EMG is detected by each sensor, corresponding to intent to move a particular effector. This system can potentially provide independent signal sources for control of individual effectors within a limb prosthesis. The use of implanted devices supports inter-day signal repeatability. We report on efforts in preparation for human clinical trials, including animal testing, and a first-in-human proof of principle demonstration where the subject was able to intuitively and simultaneously control two DOF in a hand and wrist prosthesis. PMID:21371058

Gestures, vocalizations, and memory in language origins.

PubMed

Aboitiz, Francisco

2012-01-01

THIS ARTICLE DISCUSSES THE POSSIBLE HOMOLOGIES BETWEEN THE HUMAN LANGUAGE NETWORKS AND COMPARABLE AUDITORY PROJECTION SYSTEMS IN THE MACAQUE BRAIN, IN AN ATTEMPT TO RECONCILE TWO EXISTING VIEWS ON LANGUAGE EVOLUTION: one that emphasizes hand control and gestures, and the other that emphasizes auditory-vocal mechanisms. The capacity for language is based on relatively well defined neural substrates whose rudiments have been traced in the non-human primate brain. At its core, this circuit constitutes an auditory-vocal sensorimotor circuit with two main components, a "ventral pathway" connecting anterior auditory regions with anterior ventrolateral prefrontal areas, and a "dorsal pathway" connecting auditory areas with parietal areas and with posterior ventrolateral prefrontal areas via the arcuate fasciculus and the superior longitudinal fasciculus. In humans, the dorsal circuit is especially important for phonological processing and phonological working memory, capacities that are critical for language acquisition and for complex syntax processing. In the macaque, the homolog of the dorsal circuit overlaps with an inferior parietal-premotor network for hand and gesture selection that is under voluntary control, while vocalizations are largely fixed and involuntary. The recruitment of the dorsal component for vocalization behavior in the human lineage, together with a direct cortical control of the subcortical vocalizing system, are proposed to represent a fundamental innovation in human evolution, generating an inflection point that permitted the explosion of vocal language and human communication. In this context, vocal communication and gesturing have a common history in primate communication.

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

PubMed

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.

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

PubMed Central

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

2017-01-01

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. PMID:28420135

Through the looking glass: counter-mirror activation following incompatible sensorimotor learning.

PubMed

Catmur, Caroline; Gillmeister, Helge; Bird, Geoffrey; Liepelt, Roman; Brass, Marcel; Heyes, Cecilia

2008-09-01

The mirror system, comprising cortical areas that allow the actions of others to be represented in the observer's own motor system, is thought to be crucial for the development of social cognition in humans. Despite the importance of the human mirror system, little is known about its origins. We investigated the role of sensorimotor experience in the development of the mirror system. Functional magnetic resonance imaging was used to measure neural responses to observed hand and foot actions following one of two types of training. During training, participants in the Compatible (control) group made mirror responses to observed actions (hand responses were made to hand stimuli and foot responses to foot stimuli), whereas the Incompatible group made counter-mirror responses (hand to foot and foot to hand). Comparison of these groups revealed that, after training to respond in a counter-mirror fashion, the relative action observation properties of the mirror system were reversed; areas that showed greater responses to observation of hand actions in the Compatible group responded more strongly to observation of foot actions in the Incompatible group. These results suggest that, rather than being innate or the product of unimodal visual or motor experience, the mirror properties of the mirror system are acquired through sensorimotor learning.

Cardiac Structure and Function in Humans: A New Cardiovascular Physiology Laboratory

ERIC Educational Resources Information Center

Song, Su; Burleson, Paul D.; Passo, Stanley; Messina, Edward J.; Levine, Norman; Thompson, Carl I.; Belloni, Francis L.; Recchia, Fabio A.; Ojaimi, Caroline; Kaley, Gabor; Hintze, Thomas H.

2009-01-01

As the traditional cardiovascular control laboratory has disappeared from the first-year medical school curriculum, we have recognized the need to develop another "hands-on" experience as a vehicle for wide-ranging discussions of cardiovascular control mechanisms. Using an echocardiograph, an automatic blood pressure cuff, and a reclining bicycle,…

Motivation and motor control: hemispheric specialization for approach motivation reverses with handedness.

PubMed

Brookshire, Geoffrey; Casasanto, Daniel

2012-01-01

According to decades of research on affective motivation in the human brain, approach motivational states are supported primarily by the left hemisphere and avoidance states by the right hemisphere. The underlying cause of this specialization, however, has remained unknown. Here we conducted a first test of the Sword and Shield Hypothesis (SSH), according to which the hemispheric laterality of affective motivation depends on the laterality of motor control for the dominant hand (i.e., the "sword hand," used preferentially to perform approach actions) and the nondominant hand (i.e., the "shield hand," used preferentially to perform avoidance actions). To determine whether the laterality of approach motivation varies with handedness, we measured alpha-band power (an inverse index of neural activity) in right- and left-handers during resting-state electroencephalography and analyzed hemispheric alpha-power asymmetries as a function of the participants' trait approach motivational tendencies. Stronger approach motivation was associated with more left-hemisphere activity in right-handers, but with more right-hemisphere activity in left-handers. The hemispheric correlates of approach motivation reversed between right- and left-handers, consistent with the way they typically use their dominant and nondominant hands to perform approach and avoidance actions. In both right- and left-handers, approach motivation was lateralized to the same hemisphere that controls the dominant hand. This covariation between neural systems for action and emotion provides initial support for the SSH.

Computer-aided training sensorimotor cortex functions in humans before the upper limb transplantation using virtual reality and sensory feedback.

PubMed

Kurzynski, Marek; Jaskolska, Anna; Marusiak, Jaroslaw; Wolczowski, Andrzej; Bierut, Przemyslaw; Szumowski, Lukasz; Witkowski, Jerzy; Kisiel-Sajewicz, Katarzyna

2017-08-01

One of the biggest problems of upper limb transplantation is lack of certainty as to whether a patient will be able to control voluntary movements of transplanted hands. Based on findings of the recent research on brain cortex plasticity, a premise can be drawn that mental training supported with visual and sensory feedback can cause structural and functional reorganization of the sensorimotor cortex, which leads to recovery of function associated with the control of movements performed by the upper limbs. In this study, authors - based on the above observations - propose the computer-aided training (CAT) system, which generating visual and sensory stimuli, should enhance the effectiveness of mental training applied to humans before upper limb transplantation. The basis for the concept of computer-aided training system is a virtual hand whose reaching and grasping movements the trained patient can observe on the VR headset screen (visual feedback) and whose contact with virtual objects the patient can feel as a touch (sensory feedback). The computer training system is composed of three main components: (1) the system generating 3D virtual world in which the patient sees the virtual limb from the perspective as if it were his/her own hand; (2) sensory feedback transforming information about the interaction of the virtual hand with the grasped object into mechanical vibration; (3) the therapist's panel for controlling the training course. Results of the case study demonstrate that mental training supported with visual and sensory stimuli generated by the computer system leads to a beneficial change of the brain activity related to motor control of the reaching in the patient with bilateral upper limb congenital transverse deficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

On the role of exchange of power and information signals in control and stability of the human-robot interaction

NASA Technical Reports Server (NTRS)

Kazerooni, H.

1991-01-01

A human's ability to perform physical tasks is limited, not only by his intelligence, but by his physical strength. If, in an appropriate environment, a machine's mechanical power is closely integrated with a human arm's mechanical power under the control of the human intellect, the resulting system will be superior to a loosely integrated combination of a human and a fully automated robot. Therefore, we must develop a fundamental solution to the problem of 'extending' human mechanical power. The work presented here defines 'extenders' as a class of robot manipulators worn by humans to increase human mechanical strength, while the wearer's intellect remains the central control system for manipulating the extender. The human, in physical contact with the extender, exchanges power and information signals with the extender. The aim is to determine the fundamental building blocks of an intelligent controller, a controller which allows interaction between humans and a broad class of computer-controlled machines via simultaneous exchange of both power and information signals. The prevalent trend in automation has been to physically separate the human from the machine so the human must always send information signals via an intermediary device (e.g., joystick, pushbutton, light switch). Extenders, however are perfect examples of self-powered machines that are built and controlled for the optimal exchange of power and information signals with humans. The human wearing the extender is in physical contact with the machine, so power transfer is unavoidable and information signals from the human help to control the machine. Commands are transferred to the extender via the contact forces and the EMG signals between the wearer and the extender. The extender augments human motor ability without accepting any explicit commands: it accepts the EMG signals and the contact force between the person's arm and the extender, and the extender 'translates' them into a desired position. In this unique configuration, mechanical power transfer between the human and the extender occurs because the human is pushing against the extender. The extender transfers to the human's hand, in feedback fashion, a scaled-down version of the actual external load which the extender is manipulating. This natural feedback force on the human's hand allows him to 'feel' a modified version of the external forces on the extender. The information signals from the human (e.g., EMG signals) to the computer reflect human cognitive ability, and the power transfer between the human and the machine (e.g., physical interaction) reflects human physical ability. Thus the information transfer to the machine augments cognitive ability, and the power transfer augments motor ability. These two actions are coupled through the human cognitive/motor dynamic behavior. The goal is to derive the control rules for a class of computer-controlled machines that augment human physical and cognitive abilities in certain manipulative tasks.

Microgravity human factors workstation development

NASA Technical Reports Server (NTRS)

Whitmore, Mihriban; Wilmington, Robert P.; Morris, Randy B.; Jensen, Dean G.

1992-01-01

Microgravity evaluations of workstation hardware as well as its system components were found to be very useful for determining the expected needs of the Space Station crew and for refining overall workstation design. Research at the Johnson Space Center has been carried out to provide optimal workstation design and human interface. The research included evaluations of hand controller configurations for robots and free flyers, the identification of cursor control device requirements, and the examination of anthropometric issues of workstation design such as reach, viewing distance, and head clearance.

Unsteady hydrodynamic forces acting on a robotic arm and its flow field: application to the crawl stroke.

PubMed

Takagi, Hideki; Nakashima, Motomu; Ozaki, Takashi; Matsuuchi, Kazuo

2014-04-11

This study aims to clarify the mechanisms by which unsteady hydrodynamic forces act on the hand of a swimmer during a crawl stroke. Measurements were performed for a hand attached to a robotic arm with five degrees of freedom independently controlled by a computer. The computer was programmed so the hand and arm mimicked a human performing the stroke. We directly measured forces on the hand and pressure distributions around it at 200 Hz; flow fields underwater near the hand were obtained via 2D particle image velocimetry (PIV). The data revealed two mechanisms that generate unsteady forces during a crawl stroke. One is the unsteady lift force generated when hand movement changes direction during the stroke, leading to vortex shedding and bound vortex created around it. This bound vortex circulation results in a lift that contributes to the thrust. The other occurs when the hand moves linearly with a large angle of attack, creating a Kármán vortex street. This street alternatively sheds clockwise and counterclockwise vortices, resulting in a quasi-steady drag contributing to the thrust. We presume that professional swimmers benefit from both mechanisms. Further studies are necessary in which 3D flow fields are measured using a 3D PIV system and a human swimmer. Copyright © 2014 Elsevier Ltd. All rights reserved.

Human machine interaction via the transfer of power and information signals

NASA Technical Reports Server (NTRS)

Kazerooni, H.; Foslien, W. K.; Anderson, B. J.; Hessburg, T. M.

1989-01-01

Robot manipulators are designed to perform tasks which would otherwise be executed by a human operator. No manipulator can even approach the speed and accuracy with which humans execute these tasks. But manipulators have the capability to exceed human ability in one particular area: strength. Through any reasonable observation and experience, the human's ability to perform a variety of physical tasks is limited not by his intelligence, but by his physical strength. If, in the appropriate environment, we can more closely integrate the mechanical power of a machine with intellectually driven human hand under the supervisory control of the human's intellect, we will then have a system which is superior to a loosely-integrated combination of a human and his fully automated robot as in the present day robotic systems. We must therefore develop a fundamental approach to the problem of this extending human mechanical power in certain environments. Extenders will be a class of robots worn by humans to increase human mechanical ability, while the wearer's intellect remains the central intelligent control system for manipulating the extender. The human body, in physical contact with the extender, exchanges information signals and power with the extender. Commands are transferred to the extender via the contact forces between the wearer and the extender as opposed to use of joystick (master arm), push-button or key-board to execute such commands that were used in previous man amplifiers. Instead, the operator becomes an integral part of the extender while executing the task. In this unique configuration the mechanical power transfer between the human and extender occurs in addition to information signal transfer. When the wearer uses the extender to touch and manipulate an object, the extender transfers to the wearer's hand, in feedback fashion, a scaled-down value of the actual external load which the extender is manipulating. This natural feedback force on the wearer's hand allows him to feel the scaled-down value of the external forces in the manipulations. Extenders can be utilized to maneuver very heavy loads in factories, shipyards, airports, and construction sites. In some instances, for example, extenders can replace forklifts. The experimental results for a prototype extender are discussed.

Human-computer interface glove using flexible piezoelectric sensors

NASA Astrophysics Data System (ADS)

Cha, Youngsu; Seo, Jeonggyu; Kim, Jun-Sik; Park, Jung-Min

2017-05-01

In this note, we propose a human-computer interface glove based on flexible piezoelectric sensors. We select polyvinylidene fluoride as the piezoelectric material for the sensors because of advantages such as a steady piezoelectric characteristic and good flexibility. The sensors are installed in a fabric glove by means of pockets and Velcro bands. We detect changes in the angles of the finger joints from the outputs of the sensors, and use them for controlling a virtual hand that is utilized in virtual object manipulation. To assess the sensing ability of the piezoelectric sensors, we compare the processed angles from the sensor outputs with the real angles from a camera recoding. With good agreement between the processed and real angles, we successfully demonstrate the user interaction system with the virtual hand and interface glove based on the flexible piezoelectric sensors, for four hand motions: fist clenching, pinching, touching, and grasping.

Development of a test protocol for evaluating EVA glove performance

NASA Technical Reports Server (NTRS)

Hinman, Elaine M.

1992-01-01

Testing gloved hand performance involves work from several disciplines. Evaluations performed in the course of reenabling a disabled hand, designing a robotic end effector or master controller, or hard-suit design have all yielded relevant information, and, in most cases, produced performance test methods. Most times, these test methods have been primarily oriented toward their parent discipline. For space operations, a comparative test which would provide a way to quantify pressure glove and end effector performance would be useful in dividing tasks between humans and robots. Such a test would have to rely heavily on sensored measurement, as opposed to questionnaires, to produce relevant data. However, at some point human preference would have to be taken into account. This paper presents a methodology for evaluating gloved hand performance which attempts to respond to these issues. Glove testing of a prototype glove design using this method is described.

Hand anthropometry of Indian women.

PubMed

Nag, Anjali; Nag, P K; Desai, Hina

2003-06-01

Data on the physical dimension of the hand of Indian women are scanty. This information is necessary to ascertain human-machine compatibility in the design of manual systems for the bare and gloved hand, such as design and sizing of hand tools, controls, knobs and other applications in different kinds of precision and power grips. The present study was undertaken to generate hand anthropometric data of 95 women, working in informal industries (beedi, agarbatti and garment making). Fifty one hand measurements of the right hand (lengths, breadths, circumferences, depths, spreads and clearances of hand and fingers) were taken, using anthropometric sliding and spreading calipers, measuring tape and handgrip strength dynamometer. The data were statistically analyzed to determine the normality of data and the percentile values of different hand dimensions, and simple and multiple regression analysis were done to determine better predictors of hand length and grip strength. The hand breadths, circumferences and depths were approximately normally distributed, with some deviation in case of the finger lengths. Hand length was significantly correlated with the fist, wrist and finger circumferences. The fist and wrist circumferences, in combination, were better predictors of hand length. The hand lengths, breadths and depths, including finger joints of the Indian women studied were smaller than those of American, British and West Indian women. The hand circumferences of the Indian women were also smaller than the American women. Grip strengths of Indian women (20.36 +/- 3.24 kg) were less than those of American, British and West Indian women. Grip strength was found to be statistically significant with hand dimensions, such as hand height perpendicular to wrist crease (digit 5), proximal interphalangeal joint breadth (digit 3) and hand spread across wedge 1. The women who are forced to frequently use cutters, strippers and other tools, which are not optimally designed to their hand dimensions and strength range, might have higher prevalence of clinical symptoms and disorders of the hand. In view of the human hand-tool interface requirements, the present data on Indian women would be useful for ergo-design applications of hand tools and devices.

Embodiment and Estrangement: Results from a First-in-Human "Intelligent BCI" Trial.

PubMed

Gilbert, F; Cook, M; O'Brien, T; Illes, J

2017-11-11

While new generations of implantable brain computer interface (BCI) devices are being developed, evidence in the literature about their impact on the patient experience is lagging. In this article, we address this knowledge gap by analysing data from the first-in-human clinical trial to study patients with implanted BCI advisory devices. We explored perceptions of self-change across six patients who volunteered to be implanted with artificially intelligent BCI devices. We used qualitative methodological tools grounded in phenomenology to conduct in-depth, semi-structured interviews. Results show that, on the one hand, BCIs can positively increase a sense of the self and control; on the other hand, they can induce radical distress, feelings of loss of control, and a rupture of patient identity. We conclude by offering suggestions for the proactive creation of preparedness protocols specific to intelligent-predictive and advisory-BCI technologies essential to prevent potential iatrogenic harms.

Effects of knowledge and internal locus of control in groups of health care workers judging likelihood of pathogen transfer.

PubMed

McLaughlin, Anne Collins; Walsh, Fran; Bryant, Michelle

2013-08-01

A study was conducted to measure the effects of attitudes and beliefs on the risk judgments of health care workers. Lack of hand hygiene compliance is a worldwide issue in health care, contributing to infections, fatalities, and increased health care costs. Human factors methods are a promising solution to the problem of compliance, although thus far, the concentration has been on process and engineering methods, such as the design of no-touch sinks. Factors internal to the health care worker, such as their attitudes and beliefs about hand hygiene, have received less attention. For this study, three groups of health care workers completed measures of attitudes, control beliefs, and hand hygiene knowledge. They then provided risk judgments of touching various surfaces via a factorial survey. Attitudes, knowledge, control beliefs, and surface type all predicted the risk judgments of the sample of health care workers, with differences between professional groups. Health care workers perceive less risk when touching surfaces,which may explain historically low rates of hand hygiene compliance after surface contact. Although more research is needed to directly connect risk judgments to failures of hand hygiene, the current results can inform interventions targeting the internal attitudes and beliefs of health care workers.

A blueprint for a Human Epigenome Project: the AACR Human Epigenome Workshop.

PubMed

Jones, Peter A; Martienssen, Robert

2005-12-15

Epigenetic processes control the packaging and function of the human genome and contribute to normal and pathologic states, including cancer. The time is ripe to undertake an international effort to identify all the chemical changes and relationships between chromatin constituents that provide function to the genetic code. A timely workshop of leading experts, convened by the American Association for Cancer Research (AACR), confirmed that the technology is at hand to begin defining human epigenomes at high resolution.

Hand posture classification using electrocorticography signals in the gamma band over human sensorimotor brain areas

NASA Astrophysics Data System (ADS)

Chestek, Cynthia A.; Gilja, Vikash; Blabe, Christine H.; Foster, Brett L.; Shenoy, Krishna V.; Parvizi, Josef; Henderson, Jaimie M.

2013-04-01

Objective. Brain-machine interface systems translate recorded neural signals into command signals for assistive technology. In individuals with upper limb amputation or cervical spinal cord injury, the restoration of a useful hand grasp could significantly improve daily function. We sought to determine if electrocorticographic (ECoG) signals contain sufficient information to select among multiple hand postures for a prosthetic hand, orthotic, or functional electrical stimulation system.Approach. We recorded ECoG signals from subdural macro- and microelectrodes implanted in motor areas of three participants who were undergoing inpatient monitoring for diagnosis and treatment of intractable epilepsy. Participants performed five distinct isometric hand postures, as well as four distinct finger movements. Several control experiments were attempted in order to remove sensory information from the classification results. Online experiments were performed with two participants. Main results. Classification rates were 68%, 84% and 81% for correct identification of 5 isometric hand postures offline. Using 3 potential controls for removing sensory signals, error rates were approximately doubled on average (2.1×). A similar increase in errors (2.6×) was noted when the participant was asked to make simultaneous wrist movements along with the hand postures. In online experiments, fist versus rest was successfully classified on 97% of trials; the classification output drove a prosthetic hand. Online classification performance for a larger number of hand postures remained above chance, but substantially below offline performance. In addition, the long integration windows used would preclude the use of decoded signals for control of a BCI system. Significance. These results suggest that ECoG is a plausible source of command signals for prosthetic grasp selection. Overall, avenues remain for improvement through better electrode designs and placement, better participant training, and characterization of non-stationarities such that ECoG could be a viable signal source for grasp control for amputees or individuals with paralysis.

Double nerve intraneural interface implant on a human amputee for robotic hand control.

PubMed

Rossini, Paolo M; Micera, Silvestro; Benvenuto, Antonella; Carpaneto, Jacopo; Cavallo, Giuseppe; Citi, Luca; Cipriani, Christian; Denaro, Luca; Denaro, Vincenzo; Di Pino, Giovanni; Ferreri, Florinda; Guglielmelli, Eugenio; Hoffmann, Klaus-Peter; Raspopovic, Stanisa; Rigosa, Jacopo; Rossini, Luca; Tombini, Mario; Dario, Paolo

2010-05-01

The principle underlying this project is that, despite nervous reorganization following upper limb amputation, original pathways and CNS relays partially maintain their function and can be exploited for interfacing prostheses. Aim of this study is to evaluate a novel peripheral intraneural multielectrode for multi-movement prosthesis control and for sensory feed-back, while assessing cortical reorganization following the re-acquired stream of data. Four intrafascicular longitudinal flexible multielectrodes (tf-LIFE4) were implanted in the median and ulnar nerves of an amputee; they reliably recorded output signals for 4 weeks. Artificial intelligence classifiers were used off-line to analyse LIFE signals recorded during three distinct hand movements under voluntary order. Real-time control of motor output was achieved for the three actions. When applied off-line artificial intelligence reached >85% real-time correct classification of trials. Moreover, different types of current stimulation were determined to allow reproducible and localized hand/fingers sensations. Cortical organization was observed via TMS in parallel with partial resolution of symptoms due to the phantom-limb syndrome (PLS). tf-LIFE4s recorded output signals in human nerves for 4 weeks, though the efficacy of sensory stimulation decayed after 10 days. Recording from a number of fibres permitted a high percentage of distinct actions to be classified correctly. Reversal of plastic changes and alleviation of PLS represent corollary findings of potential therapeutic benefit. This study represents a breakthrough in robotic hand use in amputees. Copyright 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Human's Capability to Discriminate Spatial Forces at the Big Toe.

PubMed

Hagengruber, Annette; Höppner, Hannes; Vogel, Jörn

2018-01-01

A key factor for reliable object manipulation is the tactile information provided by the skin of our hands. As this sensory information is so essential in our daily life it should also be provided during teleoperation of robotic devices or in the control of myoelectric prostheses. It is well-known that feeding back the tactile information to the user can lead to a more natural and intuitive control of robotic devices. However, in some applications it is difficult to use the hands as natural feedback channels since they may already be overloaded with other tasks or, e.g., in case of hand prostheses not accessible at all. Many alternatives for tactile feedback to the human hand have already been investigated. In particular, one approach shows that humans can integrate uni-directional (normal) force feedback at the toe into their sensorimotor-control loop. Extending this work, we investigate the human's capability to discriminate spatial forces at the bare front side of their toe. A state-of-the-art haptic feedback device was used to apply forces with three different amplitudes-2 N, 5 N, and 8 N-to subjects' right big toes. During the experiments, different force stimuli were presented, i.e., direction of the applied force was changed, such that tangential components occured. In total the four directions up (distal), down (proximal), left (medial), and right (lateral) were tested. The proportion of the tangential force was varied corresponding to a directional change of 5° to 25° with respect to the normal force. Given these force stimuli, the subjects' task was to identify the direction of the force change. We found the amplitude of the force as well as the proportion of tangential forces to have a significant influence on the success rate. Furthermore, the direction right showed a significantly different successrate from all other directions. The stimuli with a force amplitude of 8 N achieved success rates over 89% in all directions. The results of the user study provide evidence that the subjects were able to discriminate spatial forces at their toe within defined force amplitudes and tangential proportion.

Human's Capability to Discriminate Spatial Forces at the Big Toe

PubMed Central

Hagengruber, Annette; Höppner, Hannes; Vogel, Jörn

2018-01-01

A key factor for reliable object manipulation is the tactile information provided by the skin of our hands. As this sensory information is so essential in our daily life it should also be provided during teleoperation of robotic devices or in the control of myoelectric prostheses. It is well-known that feeding back the tactile information to the user can lead to a more natural and intuitive control of robotic devices. However, in some applications it is difficult to use the hands as natural feedback channels since they may already be overloaded with other tasks or, e.g., in case of hand prostheses not accessible at all. Many alternatives for tactile feedback to the human hand have already been investigated. In particular, one approach shows that humans can integrate uni-directional (normal) force feedback at the toe into their sensorimotor-control loop. Extending this work, we investigate the human's capability to discriminate spatial forces at the bare front side of their toe. A state-of-the-art haptic feedback device was used to apply forces with three different amplitudes—2 N, 5 N, and 8 N—to subjects' right big toes. During the experiments, different force stimuli were presented, i.e., direction of the applied force was changed, such that tangential components occured. In total the four directions up (distal), down (proximal), left (medial), and right (lateral) were tested. The proportion of the tangential force was varied corresponding to a directional change of 5° to 25° with respect to the normal force. Given these force stimuli, the subjects' task was to identify the direction of the force change. We found the amplitude of the force as well as the proportion of tangential forces to have a significant influence on the success rate. Furthermore, the direction right showed a significantly different successrate from all other directions. The stimuli with a force amplitude of 8 N achieved success rates over 89% in all directions. The results of the user study provide evidence that the subjects were able to discriminate spatial forces at their toe within defined force amplitudes and tangential proportion. PMID:29692718

Central Nervous System Control of Voice and Swallowing

PubMed Central

Ludlow, Christy L.

2015-01-01

This review of the central nervous control systems for voice and swallowing has suggested that the traditional concepts of a separation between cortical and limbic and brain stem control should be refined and more integrative. For voice production, a separation of the non-human vocalization system from the human learned voice production system has been posited based primarily on studies of non-human primates. However, recent humans studies of emotionally based vocalizations and human volitional voice production has shown more integration between these two systems than previously proposed. Recent human studies have shown that reflexive vocalization as well as learned voice production not involving speech, involve a common integrative system. On the other hand, recent studies of non-human primates have provided evidence of some cortical activity during vocalization and cortical changes with training during vocal behavior. For swallowing, evidence from the macaque and functional brain imaging in humans indicates that the control for the pharyngeal phase of swallowing is not primarily under brain stem mechanisms as previously proposed. Studies suggest that the initiation and patterning of swallowing for the pharyngeal phase is also under active cortical control for both spontaneous as well as volitional swallowing in awake humans and non-human primates. PMID:26241238

Illumination-invariant hand gesture recognition

NASA Astrophysics Data System (ADS)

Mendoza-Morales, América I.; Miramontes-Jaramillo, Daniel; Kober, Vitaly

2015-09-01

In recent years, human-computer interaction (HCI) has received a lot of interest in industry and science because it provides new ways to interact with modern devices through voice, body, and facial/hand gestures. The application range of the HCI is from easy control of home appliances to entertainment. Hand gesture recognition is a particularly interesting problem because the shape and movement of hands usually are complex and flexible to be able to codify many different signs. In this work we propose a three step algorithm: first, detection of hands in the current frame is carried out; second, hand tracking across the video sequence is performed; finally, robust recognition of gestures across subsequent frames is made. Recognition rate highly depends on non-uniform illumination of the scene and occlusion of hands. In order to overcome these issues we use two Microsoft Kinect devices utilizing combined information from RGB and infrared sensors. The algorithm performance is tested in terms of recognition rate and processing time.

The Design of Hand Gestures for Human-Computer Interaction: Lessons from Sign Language Interpreters.

PubMed

Rempel, David; Camilleri, Matt J; Lee, David L

2015-10-01

The design and selection of 3D modeled hand gestures for human-computer interaction should follow principles of natural language combined with the need to optimize gesture contrast and recognition. The selection should also consider the discomfort and fatigue associated with distinct hand postures and motions, especially for common commands. Sign language interpreters have extensive and unique experience forming hand gestures and many suffer from hand pain while gesturing. Professional sign language interpreters (N=24) rated discomfort for hand gestures associated with 47 characters and words and 33 hand postures. Clear associations of discomfort with hand postures were identified. In a nominal logistic regression model, high discomfort was associated with gestures requiring a flexed wrist, discordant adjacent fingers, or extended fingers. These and other findings should be considered in the design of hand gestures to optimize the relationship between human cognitive and physical processes and computer gesture recognition systems for human-computer input.

Developmental vision determines the reference frame for the multisensory control of action.

PubMed

Röder, Brigitte; Kusmierek, Anna; Spence, Charles; Schicke, Tobias

2007-03-13

Both animal and human studies suggest that action goals are defined in external coordinates regardless of their sensory modality. The present study used an auditory-manual task to test whether the default use of such an external reference frame is innately determined or instead acquired during development because of the increasing dominance of vision over manual control. In Experiment I, congenitally blind, late blind, and age-matched sighted adults had to press a left or right response key depending on the bandwidth of pink noise bursts presented from either the left or right loudspeaker. Although the spatial location of the sounds was entirely task-irrelevant, all groups responded more efficiently with uncrossed hands when the sound was presented from the same side as the responding hand ("Simon effect"). This effect reversed with crossed hands only in the congenitally blind: They responded faster with the hand that was located contralateral to the sound source. In Experiment II, the instruction to the participants was changed: They now had to respond with the hand located next to the sound source. In contrast to Experiment I ("Simon-task"), this task required an explicit matching of the sound's location with the position of the responding hand. In Experiment II, the congenitally blind participants showed a significantly larger crossing deficit than both the sighted and late blind adults. This pattern of results implies that developmental vision induces the default use of an external coordinate frame for multisensory action control; this facilitates not only visual but also auditory-manual control.

Control of joint motion simulators for biomechanical research

NASA Technical Reports Server (NTRS)

Colbaugh, R.; Glass, K.

1992-01-01

The authors present a hierarchical adaptive algorithm for controlling upper extremity human joint motion simulators. A joint motion simulator is a computer-controlled, electromechanical system which permits the application of forces to the tendons of a human cadaver specimen in such a way that the cadaver joint under study achieves a desired motion in a physiologic manner. The proposed control scheme does not require knowledge of the cadaver specimen dynamic model, and solves on-line the indeterminate problem which arises because human joints typically possess more actuators than degrees of freedom. Computer simulation results are given for an elbow/forearm system and wrist/hand system under hierarchical control. The results demonstrate that any desired normal joint motion can be accurately tracked with the proposed algorithm. These simulation results indicate that the controller resolved the indeterminate problem redundancy in a physiologic manner, and show that the control scheme was robust to parameter uncertainty and to sensor noise.

Tool use and the distalization of the end-effector

PubMed Central

Bonaiuto, James B.; Jacobs, Stéphane; Frey, Scott H.

2009-01-01

We review recent neurophysiological data from macaques and humans suggesting that the use of tools extends the internal representation of the actor’s hand, and relate it to our modeling of the visual control of grasping. We introduce the idea that, in addition to extending the body schema to incorporate the tool, tool use involves distalization of the end-effector from hand to tool. Different tools extend the body schema in different ways, with a displaced visual target and a novel, task-specific processing of haptic feedback to the hand. This distalization is critical in order to exploit the unique functional capacities engendered by complex tools. PMID:19347356

Grip Force and 3D Push-Pull Force Estimation Based on sEMG and GRNN

PubMed Central

Wu, Changcheng; Zeng, Hong; Song, Aiguo; Xu, Baoguo

2017-01-01

The estimation of the grip force and the 3D push-pull force (push and pull force in the three dimension space) from the electromyogram (EMG) signal is of great importance in the dexterous control of the EMG prosthetic hand. In this paper, an action force estimation method which is based on the eight channels of the surface EMG (sEMG) and the Generalized Regression Neural Network (GRNN) is proposed to meet the requirements of the force control of the intelligent EMG prosthetic hand. Firstly, the experimental platform, the acquisition of the sEMG, the feature extraction of the sEMG and the construction of GRNN are described. Then, the multi-channels of the sEMG when the hand is moving are captured by the EMG sensors attached on eight different positions of the arm skin surface. Meanwhile, a grip force sensor and a three dimension force sensor are adopted to measure the output force of the human's hand. The characteristic matrix of the sEMG and the force signals are used to construct the GRNN. The mean absolute value and the root mean square of the estimation errors, the correlation coefficients between the actual force and the estimated force are employed to assess the accuracy of the estimation. Analysis of variance (ANOVA) is also employed to test the difference of the force estimation. The experiments are implemented to verify the effectiveness of the proposed estimation method and the results show that the output force of the human's hand can be correctly estimated by using sEMG and GRNN method. PMID:28713231

Grip Force and 3D Push-Pull Force Estimation Based on sEMG and GRNN.

PubMed

Wu, Changcheng; Zeng, Hong; Song, Aiguo; Xu, Baoguo

2017-01-01

The estimation of the grip force and the 3D push-pull force (push and pull force in the three dimension space) from the electromyogram (EMG) signal is of great importance in the dexterous control of the EMG prosthetic hand. In this paper, an action force estimation method which is based on the eight channels of the surface EMG (sEMG) and the Generalized Regression Neural Network (GRNN) is proposed to meet the requirements of the force control of the intelligent EMG prosthetic hand. Firstly, the experimental platform, the acquisition of the sEMG, the feature extraction of the sEMG and the construction of GRNN are described. Then, the multi-channels of the sEMG when the hand is moving are captured by the EMG sensors attached on eight different positions of the arm skin surface. Meanwhile, a grip force sensor and a three dimension force sensor are adopted to measure the output force of the human's hand. The characteristic matrix of the sEMG and the force signals are used to construct the GRNN. The mean absolute value and the root mean square of the estimation errors, the correlation coefficients between the actual force and the estimated force are employed to assess the accuracy of the estimation. Analysis of variance (ANOVA) is also employed to test the difference of the force estimation. The experiments are implemented to verify the effectiveness of the proposed estimation method and the results show that the output force of the human's hand can be correctly estimated by using sEMG and GRNN method.

Illusory movement perception improves motor control for prosthetic hands

PubMed Central

Marasco, Paul D.; Hebert, Jacqueline S.; Sensinger, Jon W.; Shell, Courtney E.; Schofield, Jonathon S.; Thumser, Zachary C.; Nataraj, Raviraj; Beckler, Dylan T.; Dawson, Michael R.; Blustein, Dan H.; Gill, Satinder; Mensh, Brett D.; Granja-Vazquez, Rafael; Newcomb, Madeline D.; Carey, Jason P.; Orzell, Beth M.

2018-01-01

To effortlessly complete an intentional movement, the brain needs feedback from the body regarding the movement’s progress. This largely non-conscious kinesthetic sense helps the brain to learn relationships between motor commands and outcomes to correct movement errors. Prosthetic systems for restoring function have predominantly focused on controlling motorized joint movement. Without the kinesthetic sense, however, these devices do not become intuitively controllable. Here we report a method for endowing human amputees with a kinesthetic perception of dexterous robotic hands. Vibrating the muscles used for prosthetic control via a neural-machine interface produced the illusory perception of complex grip movements. Within minutes, three amputees integrated this kinesthetic feedback and improved movement control. Combining intent, kinesthesia, and vision instilled participants with a sense of agency over the robotic movements. This feedback approach for closed-loop control opens a pathway to seamless integration of minds and machines. PMID:29540617

A neural network simulating human reach-grasp coordination by continuous updating of vector positioning commands.

PubMed

Ulloa, Antonio; Bullock, Daniel

2003-10-01

We developed a neural network model to simulate temporal coordination of human reaching and grasping under variable initial grip apertures and perturbations of object size and object location/orientation. The proposed model computes reach-grasp trajectories by continuously updating vector positioning commands. The model hypotheses are (1) hand/wrist transport, grip aperture, and hand orientation control modules are coupled by a gating signal that fosters synchronous completion of the three sub-goals. (2) Coupling from transport and orientation velocities to aperture control causes maximum grip apertures that scale with these velocities and exceed object size. (3) Part of the aperture trajectory is attributable to an aperture-reducing passive biomechanical effect that is stronger for larger apertures. (4) Discrepancies between internal representations of targets partially inhibit the gating signal, leading to movement time increases that compensate for perturbations. Simulations of the model replicate key features of human reach-grasp kinematics observed under three experimental protocols. Our results indicate that no precomputation of component movement times is necessary for online temporal coordination of the components of reaching and grasping.

Performance consequences of alternating directional control-response compatibility: evidence from a coal mine shuttle car simulator.

PubMed

Zupanc, Christine M; Burgess-Limerick, Robin J; Wallis, Guy

2007-08-01

To investigate error and reaction time consequences of alternating compatible and incompatible steering arrangements during a simulated obstacle avoidance task. Underground coal mine shuttle cars provide an example of a vehicle in which operators are required to alternate between compatible and incompatible steering configurations. This experiment examines the performance of 48 novice participants in a virtual analogy of an underground coal mine shuttle car. Participants were randomly assigned to a compatible condition, an incompatible condition, an alternating condition in which compatibility alternated within and between hands, or an alternating condition in which compatibility alternated between hands. Participants made fewer steering direction errors and made correct steering responses more quickly in the compatible condition. Error rate decreased over time in the incompatible condition. A compatibility effect for both errors and reaction time was also found when the control-response relationship alternated; however, performance improvements over time were not consistent. Isolating compatibility to a hand resulted in reduced error rate and faster reaction time than when compatibility alternated within and between hands. The consequences of alternating control-response relationships are higher error rates and slower responses, at least in the early stages of learning. This research highlights the importance of ensuring consistently compatible human-machine directional control-response relationships.

Human balancing of an inverted pendulum with a compliant linkage: neural control by anticipatory intermittent bias

PubMed Central

Lakie, Martin; Caplan, Nicholas; Loram, Ian D

2003-01-01

These experiments were prompted by the recent discovery that the intrinsic stiffness of the ankle is inadequate to stabilise passively the body in standing. Our hope was that showing how a large inverted pendulum was manually balanced with low intrinsic stiffness would elucidate the active control of human standing. The results show that the pendulum can be satisfactorily stabilised when intrinsic stiffness is low. Analysis of sway size shows that intrinsic stiffness actually plays little part in stabilisation. The sway duration is also substantially independent of intrinsic stiffness. This suggests that the characteristic sway of the pendulum, rather than being dictated by stiffness and inertia, may result from the control pattern of hand movements. The key points revealed by these experiments are that with low intrinsic stiffness the hand provides pendulum stability by intermittently altering the bias of the spring and, on average, the hand moves in opposition to the load. The results lead to a new and testable hypothesis; namely that in standing, the calf muscle shortens as the body sways forward and lengthens as it sways backwards. These findings are difficult to reconcile with stretch reflex control of the pendulum and are of particular relevance to standing. They may also be relevant to postural maintenance in general whenever the CNS controls muscles which operate through compliant linkages. The results also suggest that in standing, rather than providing passive stability, the intrinsic stiffness acts as an energy efficient buffer which provides decoupling between muscle and body. PMID:12832494

Development of hand exoskeleton for rehabilitation of post-stroke patient

NASA Astrophysics Data System (ADS)

Zaid, Amran Mohd; Chean, Tee Chu; Sukor, Jumadi Abdul; Hanafi, Dirman

2017-10-01

Degenerative muscle diseases characterized by loss of strength in human hand significantly affect the physical of affected individuals. A soft assistive exoskeleton glove is designed to help post-stroke patient with their rehabilitation process. The glove uses soft bending actuator which has a rubber like tender characteristic. Due to its rubber like characteristic, flexion of finger can be achieved easily through pneumatic air without considering other hand motions. The application involves a post-stroke patient to wear the soft exoskeleton glove on his paralyzed hand and control the actuation of the glove by using pneumatic air source. The fabrication of the soft bending actuator involves silicone rubber Mold Star® 15 SLOW which falls within the soft category of shore A hardness scale. The soft bending actuator is controlled by Arduino Mega 2560 as main controller board and relay module is used to trigger the 3/2-way single solenoid valve by switching on the 24VDC power supply. The actuation of the soft bending actuator can be manipulated by setting delay ON and OFF for the relay switching. Thus, the repetition of the bending motion can be customized to fulfil the rehabilitation needs of the patient.

Substance P and Calcitonin gene-related peptide expression in human periodontal ligament after root canal preparation with Reciproc Blue, WaveOne Gold, XP EndoShaper and hand files.

PubMed

Caviedes-Bucheli, J; Rios-Osorio, N; Rey-Rojas, M; Laguna-Rivero, F; Azuero-Holguin, M M; Diaz, L E; Curtidor, H; Castaneda-Ramirez, J J; Munoz, H R

2018-05-17

To quantify Substance P (SP) and Calcitonin gene-related peptide (CGRP) expression in healthy human periodontal ligament from premolars after root canal preparation with Reciproc Blue, WaveOne Gold, XP EndoShaper and hand files. A total of 50 human periodontal ligament samples were obtained from healthy mandibular premolars where extraction was indicated for orthodontic reasons. Prior to extraction, 40 of these premolars were equally divided into four groups, and root canals were prepared using four different systems: Reciproc Blue, WaveOne Gold, XP EndoShaper and a hand instrumentation technique. The remaining 10 healthy premolars were extracted without treatment and served as a negative control group. All periodontal ligament samples were processed, and SP and CGRP were measured by radioimmunoassay. The Kruskal-Wallis test was used to establish significant differences between groups and LSD post hoc comparisons were also performed. Greater SP and CGRP values were found in the hand instrumentation group, followed by the XP EndoShaper, WaveOne Gold and the Reciproc groups. The lower SP and CGRP values were for the healthy periodontal ligament group. The Kruskal-Wallis test revealed significant differences between groups (P < 0.05). Post hoc Least Significant Difference (LSD) tests revealed significant differences (P < 0.05) in SP and CGRP expression between all the comparisons except for the Reciproc Blue and WaveOne Gold group (P > 0.05). All the root canal preparation techniques tested increased SP and CGRP expression in human periodontal ligament, with hand files and XP EndoShaper instruments being associated with greater neuropeptide release compared to Reciproc Blue and WaveOne Gold files. © 2018 International Endodontic Journal. Published by John Wiley & Sons Ltd.

7 CFR 2902.18 - Hand cleaners and sanitizers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... use in removing bacteria from human hands with or without the use of water. Personal care products... and bacteria from human hands with or without the use of water are classified as hand sanitizers for...

7 CFR 2902.18 - Hand cleaners and sanitizers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... use in removing bacteria from human hands with or without the use of water. Personal care products... and bacteria from human hands with or without the use of water are classified as hand sanitizers for...

Evolution of the human hand: approaches to acquiring, analysing and interpreting the anatomical evidence

PubMed Central

MARZKE, MARY W.; MARZKE, R. F.

2000-01-01

The discovery of fossil hand bones from an early human ancestor at Olduvai Gorge in 1960, at the same level as primitive stone tools, generated a debate about the role of tools in the evolution of the human hand that has raged to the present day. Could the Olduvai hand have made the tools? Did the human hand evolve as an adaptation to tool making and tool use? The debate has been fueled by anatomical studies comparing living and fossil human and nonhuman primate hands, and by experimental observations. These have assessed the relative abilities of apes and humans to manufacture the Oldowan tools, but consensus has been hampered by disagreements about how to translate experimental data from living species into quantitative models for predicting the performance of fossil hands. Such models are now beginning to take shape as new techniques are applied to the capture, management and analysis of data on kinetic and kinematic variables ranging from hand joint structure, muscle mechanics, and the distribution and density of bone to joint movements and muscle recruitment during manipulative behaviour. The systematic comparative studies are highlighting a functional complex of features in the human hand facilitating a distinctive repertoire of grips that are apparently more effective for stone tool making than grips characterising various nonhuman primate species. The new techniques are identifying skeletal variables whose form may provide clues to the potential of fossil hominid hands for one-handed firm precision grips and fine precision manoeuvering movements, both of which are essential for habitual and effective tool making and tool use. PMID:10999274

Altered White Matter Integrity in Human Immunodeficiency Virus-Associated Neurocognitive Disorder: A Tract-Based Spatial Statistics Study.

PubMed

Oh, Se Won; Shin, Na-Young; Choi, Jun Yong; Lee, Seung-Koo; Bang, Mi Rim

2018-01-01

Human immunodeficiency virus (HIV) infection has been known to damage the microstructural integrity of white matter (WM). However, only a few studies have assessed the brain regions in HIV-associated neurocognitive disorders (HAND) with diffusion tensor imaging (DTI). Therefore, we sought to compare the DTI data between HIV patients with and without HAND using tract-based spatial statistics (TBSS). Twenty-two HIV-infected patients (10 with HAND and 12 without HAND) and 11 healthy controls (HC) were enrolled in this study. A whole-brain analysis of fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity was performed with TBSS and a subsequent 20 tract-specific region-of-interest (ROI)-based analysis to localize and compare altered WM integrity in all group contrasts. Compared with HC, patients with HAND showed decreased FA in the right frontoparietal WM including the upper corticospinal tract (CST) and increased MD and RD in the bilateral frontoparietal WM, corpus callosum, bilateral CSTs and bilateral cerebellar peduncles. The DTI values did not significantly differ between HIV patients with and without HAND or between HIV patients without HAND and HC. In the ROI-based analysis, decreased FA was observed in the right superior longitudinal fasciculus and was significantly correlated with decreased information processing speed, memory, executive function, and fine motor function in HIV patients. These results suggest that altered integrity of the frontoparietal WM contributes to cognitive dysfunction in HIV patients.

Deducing the reachable space from fingertip positions.

PubMed

Hai-Trieu Pham; Pathirana, Pubudu N

2015-01-01

The reachable space of the hand has received significant interests in the past from relevant medical researchers and health professionals. The reachable space was often computed from the joint angles acquired from a motion capture system such as gloves or markers attached to each bone of the finger. However, the contact between the hand and device can cause difficulties particularly for hand with injuries, burns or experiencing certain dermatological conditions. This paper introduces an approach to find the reachable space of the hand in a non-contact measurement form utilizing the Leap Motion Controller. The approach is based on the analysis of each position in the motion path of the fingertip acquired by the Leap Motion Controller. For each position of the fingertip, the inverse kinematic problem was solved under the physiological multiple constraints of the human hand to find a set of all possible configurations of three finger joints. Subsequently, all the sets are unified to form a set of all possible configurations specific for that motion. Finally, a reachable space is computed from the configuration corresponding to the complete extension and the complete flexion of the finger joint angles in this set.

Complex Tasks Force Hand Laterality and Technological Behaviour in Naturalistically Housed Chimpanzees: Inferences in Hominin Evolution

PubMed Central

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. PMID:22550466

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

PubMed

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.

The Design of Hand Gestures for Human-Computer Interaction: Lessons from Sign Language Interpreters

PubMed Central

Rempel, David; Camilleri, Matt J.; Lee, David L.

2015-01-01

The design and selection of 3D modeled hand gestures for human-computer interaction should follow principles of natural language combined with the need to optimize gesture contrast and recognition. The selection should also consider the discomfort and fatigue associated with distinct hand postures and motions, especially for common commands. Sign language interpreters have extensive and unique experience forming hand gestures and many suffer from hand pain while gesturing. Professional sign language interpreters (N=24) rated discomfort for hand gestures associated with 47 characters and words and 33 hand postures. Clear associations of discomfort with hand postures were identified. In a nominal logistic regression model, high discomfort was associated with gestures requiring a flexed wrist, discordant adjacent fingers, or extended fingers. These and other findings should be considered in the design of hand gestures to optimize the relationship between human cognitive and physical processes and computer gesture recognition systems for human-computer input. PMID:26028955

End-state comfort trumps handedness in object manipulation.

PubMed

Coelho, Chase J; Studenka, Breanna E; Rosenbaum, David A

2014-04-01

A goal of research on human perception and performance is to explore the relative importance of constraints shaping action selection. The present study concerned the relative importance of two constraints that have not been directly contrasted: (1) the tendency to grasp objects in ways that afford comfortable or easy-to-control final postures; and (2) the tendency to grasp objects with the dominant rather than the nondominant hand. We asked participants to reach out and grasp a horizontal rod whose left or right end was to be placed into a target after a 90° rotation. In one condition, we told participants which hand to use and let them choose an overhand or underhand initial grasp. In another condition, we told participants which grasp to use and let them choose either hand. Participants sacrificed hand preference to perform the task in a way that ensured a comfortable or easy to control thumb-up posture at the time of object placement, indicating that comfort trumped handedness. A second experiment confirmed that comfort was indeed higher for thumb-down postures than thumb-up postures. A third experiment confirmed that the choice data could be linked to objective performance differences. The results point to the importance of identifying constraint weightings for action selection and support an account of hand selection that ascribes hand preference to sensitivity to performance differences. The results do not support the hypothesis that hand preference simply reflects a bias to use the dominant hand.

Mental rotation of primate hands: human-likeness and thumb saliency.

PubMed

Bläsing, Bettina; de Castro Campos, Marcella; Schack, Thomas; Brugger, Peter

2012-08-01

Mental rotation of human hands has been found to differ essentially from mental rotation of objects in such a way that reaction times and error rates of handedness judgements are influenced by the comfort and familiarity of the presented hand postures. To investigate the role of the similarity of the presented hands to the participant's own hand, we used different primates' hands as stimuli in a mental rotation task. Five out of 24 primate hands were chosen for their ratings in human-likeness and saliency of the thumb according to a questionnaire study and presented in two mental rotation experiments; in the second experiment, they were modified in such a way that all hands appeared thumbless. Results of both experiments revealed effects of species and orientation on reaction times, and an interaction between species and hand side occurred in the second experiment. In the first experiment, the thumbless Colobus hand differed from all other hands, showing the highest reaction times and error rates and failing to show the expected medial-over-lateral advantage. In the second experiment, the eccentricity of the Colobus hand was decreased and the facilitating effect of human-likeness was slightly increased. We conclude that motor strategies were applied that relied less on the asymmetry of the stimuli but rather on their similarity to the human hand. We argue that motor simulation might facilitate the processing of incomplete stimuli by mentally completing them, especially if all stimuli can be processed in a consistent manner.

Foot-controlled robotic-enabled endoscope holder for endoscopic sinus surgery: A cadaveric feasibility study.

PubMed

Chan, Jason Y K; Leung, Iris; Navarro-Alarcon, David; Lin, Weiyang; Li, Peng; Lee, Dennis L Y; Liu, Yun-hui; Tong, Michael C F

2016-03-01

To evaluate the feasibility of a unique prototype foot-controlled robotic-enabled endoscope holder (FREE) in functional endoscopic sinus surgery. Cadaveric study. Using human cadavers, we investigated the feasibility, advantages, and disadvantages of the robotic endoscope holder in performing endoscopic sinus surgery with two hands in five cadaver heads, mimicking a single nostril three-handed technique. The FREE robot is relatively easy to use. Setup was quick, taking less than 3 minutes from docking the robot at the head of the bed to visualizing the middle meatus. The unit is also relatively small, takes up little space, and currently has four degrees of freedom. The learning curve for using the foot control was short. The use of both hands was not hindered by the presence of the endoscope in the nasal cavity. The tremor filtration also aided in the smooth movement of the endoscope, with minimal collisions. The FREE endoscope holder in an ex-vivo cadaver test corroborated the feasibility of the robotic prototype, which allows for a two-handed approach to surgery equal to a single nostril three-handed technique without the holder that may reduce operating time. Further studies will be needed to evaluate its safety profile and use in other areas of endoscopic surgery. NA. Laryngoscope, 126:566-569, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

Robonaut: A Robotic Astronaut Assistant

NASA Technical Reports Server (NTRS)

Ambrose, Robert O.; Diftler, Myron A.

2001-01-01

NASA's latest anthropomorphic robot, Robonaut, has reached a milestone in its capability. This highly dexterous robot, designed to assist astronauts in space, is now performing complex tasks at the Johnson Space Center that could previously only be carried out by humans. With 43 degrees of freedom, Robonaut is the first humanoid built for space and incorporates technology advances in dexterous hands, modular manipulators, lightweight materials, and telepresence control systems. Robonaut is human size, has a three degree of freedom (DOF) articulated waist, and two, seven DOF arms, giving it an impressive work space for interacting with its environment. Its two, five fingered hands allow manipulation of a wide range of tools. A pan/tilt head with multiple stereo camera systems provides data for both teleoperators and computer vision systems.

FUNCTIONAL RECOVERY FOLLOWING MOTOR CORTEX LESIONS IN NON-HUMAN PRIMATES: EXPERIMENTAL IMPLICATIONS FOR HUMAN STROKE PATIENTS

PubMed Central

Darling, Warren G.; Pizzimenti, Marc A.; Morecraft, Robert J.

2013-01-01

This review discusses selected classical works and contemporary research on recovery of contralesional fine hand motor function following lesions to motor areas of the cerebral cortex in non-human primates. Findings from both the classical literature and contemporary studies show that lesions of cortical motor areas induce paresis initially, but are followed by remarkable recovery of fine hand/digit motor function that depends on lesion size and post-lesion training. Indeed, in recent work where considerable quantification of fine digit function associated with grasping and manipulating small objects has been observed, very favorable recovery is possible with minimal forced use of the contralesional limb. Studies of the mechanisms underlying recovery have shown that following small lesions of the digit areas of primary motor cortex (M1), there is expansion of the digit motor representations into areas of M1 that did not produce digit movements prior to the lesion. However, after larger lesions involving the elbow, wrist and digit areas of M1, no such expansion of the motor representation was observed, suggesting that recovery was due to other cortical or subcortical areas taking over control of hand/digit movements. Recently, we showed that one possible mechanism of recovery after lesion to the arm areas of M1 and lateral premotor cortex is enhancement of corticospinal projections from the medially located supplementary motor area (M2) to spinal cord laminae containing neurons which have lost substantial input from the lateral motor areas and play a critical role in reaching and digit movements. Because human stroke and brain injury patients show variable, and usually poorer, recovery of hand motor function than that of nonhuman primates after motor cortex damage, we conclude with a discussion of implications of this work for further experimentation to improve recovery of hand function in human stroke patients. PMID:21960307

Interacting hands: the role of attention for the joint Simon effect

PubMed Central

Liepelt, Roman

2014-01-01

Recent research in monkeys and humans has shown that the presence of the hands near an object enhances spatial processing for objects presented near the hand. This study aimed to test the effect of hand position on the joint Simon effect. In Experiment 1, two human co-actors shared a Simon task while placing their response hands either near the objects appearing on the monitor or away from the monitor. Experiment 2 varied each co-actor’s hand position independently. Experiment 3 tested whether enhanced spatial processing for objects presented near the hand is obtained when replacing one of the two co-actors by a non-human event-producing rubber hand. Experiment 1 provided evidence for a Simon effect. Hand position significantly modulated the size of the Simon effect in the joint Simon task showing an increased Simon effect when the hands of both actors were located near the objects on the monitor, than when they were located away from the monitor. Experiment 2 replicated this finding showing an increased Simon effect when the actor’s hand was located near the objects on the monitor, but only when the co-actor also produced action events in spatial reference. A similar hand position effect was observed in Experiment 3 when a non-human rubber hand replaced the human co-actor. These findings suggest that external action events that are produced in spatial reference bias the distribution of attention to the area near the hand. This strengthens the weight of the spatial response codes (referential coding) and hence increases the joint Simon effect. PMID:25566140

Tactile Data Entry System

NASA Technical Reports Server (NTRS)

Adams, Richard J.

2015-01-01

The patent-pending Glove-Enabled Computer Operations (GECO) design leverages extravehicular activity (EVA) glove design features as platforms for instrumentation and tactile feedback, enabling the gloves to function as human-computer interface devices. Flexible sensors in each finger enable control inputs that can be mapped to any number of functions (e.g., a mouse click, a keyboard strike, or a button press). Tracking of hand motion is interpreted alternatively as movement of a mouse (change in cursor position on a graphical user interface) or a change in hand position on a virtual keyboard. Programmable vibro-tactile actuators aligned with each finger enrich the interface by creating the haptic sensations associated with control inputs, such as recoil of a button press.

Artificial limb representation in amputees

PubMed Central

van den Heiligenberg, Fiona M Z; Orlov, Tanya; Macdonald, Scott N; Duff, Eugene P; Henderson Slater, David; Beckmann, Christian F; Johansen-Berg, Heidi; Culham, Jody C; Makin, Tamar R

2018-01-01

Abstract The human brain contains multiple hand-selective areas, in both the sensorimotor and visual systems. Could our brain repurpose neural resources, originally developed for supporting hand function, to represent and control artificial limbs? We studied individuals with congenital or acquired hand-loss (hereafter one-handers) using functional MRI. We show that the more one-handers use an artificial limb (prosthesis) in their everyday life, the stronger visual hand-selective areas in the lateral occipitotemporal cortex respond to prosthesis images. This was found even when one-handers were presented with images of active prostheses that share the functionality of the hand but not necessarily its visual features (e.g. a ‘hook’ prosthesis). Further, we show that daily prosthesis usage determines large-scale inter-network communication across hand-selective areas. This was demonstrated by increased resting state functional connectivity between visual and sensorimotor hand-selective areas, proportional to the intensiveness of everyday prosthesis usage. Further analysis revealed a 3-fold coupling between prosthesis activity, visuomotor connectivity and usage, suggesting a possible role for the motor system in shaping use-dependent representation in visual hand-selective areas, and/or vice versa. Moreover, able-bodied control participants who routinely observe prosthesis usage (albeit less intensively than the prosthesis users) showed significantly weaker associations between degree of prosthesis observation and visual cortex activity or connectivity. Together, our findings suggest that altered daily motor behaviour facilitates prosthesis-related visual processing and shapes communication across hand-selective areas. This neurophysiological substrate for prosthesis embodiment may inspire rehabilitation approaches to improve usage of existing substitutionary devices and aid implementation of future assistive and augmentative technologies. PMID:29534154

Artificial limb representation in amputees.

PubMed

van den Heiligenberg, Fiona M Z; Orlov, Tanya; Macdonald, Scott N; Duff, Eugene P; Henderson Slater, David; Beckmann, Christian F; Johansen-Berg, Heidi; Culham, Jody C; Makin, Tamar R

2018-05-01

The human brain contains multiple hand-selective areas, in both the sensorimotor and visual systems. Could our brain repurpose neural resources, originally developed for supporting hand function, to represent and control artificial limbs? We studied individuals with congenital or acquired hand-loss (hereafter one-handers) using functional MRI. We show that the more one-handers use an artificial limb (prosthesis) in their everyday life, the stronger visual hand-selective areas in the lateral occipitotemporal cortex respond to prosthesis images. This was found even when one-handers were presented with images of active prostheses that share the functionality of the hand but not necessarily its visual features (e.g. a 'hook' prosthesis). Further, we show that daily prosthesis usage determines large-scale inter-network communication across hand-selective areas. This was demonstrated by increased resting state functional connectivity between visual and sensorimotor hand-selective areas, proportional to the intensiveness of everyday prosthesis usage. Further analysis revealed a 3-fold coupling between prosthesis activity, visuomotor connectivity and usage, suggesting a possible role for the motor system in shaping use-dependent representation in visual hand-selective areas, and/or vice versa. Moreover, able-bodied control participants who routinely observe prosthesis usage (albeit less intensively than the prosthesis users) showed significantly weaker associations between degree of prosthesis observation and visual cortex activity or connectivity. Together, our findings suggest that altered daily motor behaviour facilitates prosthesis-related visual processing and shapes communication across hand-selective areas. This neurophysiological substrate for prosthesis embodiment may inspire rehabilitation approaches to improve usage of existing substitutionary devices and aid implementation of future assistive and augmentative technologies.

Robustness of muscle synergies underlying three-dimensional force generation at the hand in healthy humans

PubMed Central

Rymer, William Z.; Beer, Randall F.

2012-01-01

Previous studies using advanced matrix factorization techniques have shown that the coordination of human voluntary limb movements may be accomplished using combinations of a small number of intermuscular coordination patterns, or muscle synergies. However, the potential use of muscle synergies for isometric force generation has been evaluated mostly using correlational methods. The results of such studies suggest that fixed relationships between the activations of pairs of muscles are relatively rare. There is also emerging evidence that the nervous system uses independent strategies to control movement and force generation, which suggests that one cannot conclude a priori that isometric force generation is accomplished by combining muscle synergies, as shown in movement control. In this study, we used non-negative matrix factorization to evaluate the ability of a few muscle synergies to reconstruct the activation patterns of human arm muscles underlying the generation of three-dimensional (3-D) isometric forces at the hand. Surface electromyographic (EMG) data were recorded from eight key elbow and shoulder muscles during 3-D force target-matching protocols performed across a range of load levels and hand positions. Four synergies were sufficient to explain, on average, 95% of the variance in EMG datasets. Furthermore, we found that muscle synergy composition was conserved across biomechanical task conditions, experimental protocols, and subjects. Our findings are consistent with the view that the nervous system can generate isometric forces by assembling a combination of a small number of muscle synergies, differentially weighted according to task constraints. PMID:22279190

Structure design for a Two-DoF myoelectric prosthetic hand to realize basic hand functions in ADLs.

PubMed

Hoshigawa, Suguru; Jiang, Yinlai; Kato, Ryu; Morishita, Soichiro; Nakamura, Tatsuhiro; Yabuki, Yoshiko; Yokoi, Hiroshi

2015-01-01

Prosthetic hands are desired by those who have lost a hand or both hands not only for decoration but also for the functions to help them with their activities of daily living (ADL). Prosthetic robotic hands that are developed to fully realize the function of a human hand are usually too expensive to be economically available, difficult to operate and maintain, or over heavy for longtime wearing. The aim of this study is therefore to develop a simplified prosthetic hand (sim-PH), which is to be controlled by myoelectric signals from the user, to realize the most important grasp motions in ADL by trading off the cost and performance. This paper reports the structure design of a two-DoF sim-PH with two motors to drive the CM joint of the thumb and the interlocked MP joints of the other four fingers. In order to optimize the structure, the model of the sim-PH was proposed based on which 7 sim-PHs with different structural parameters were manufactured and tested in a pick-and-place experiment. Correspondence analysis of the experimental results clarified the relationship between the hand functions and the shapes of fingers.

Sensitive and Flexible Polymeric Strain Sensor for Accurate Human Motion Monitoring

PubMed Central

Khan, Hassan; Kottapalli, Ajay; Asadnia, Mohsen

2018-01-01

Flexible electronic devices offer the capability to integrate and adapt with human body. These devices are mountable on surfaces with various shapes, which allow us to attach them to clothes or directly onto the body. This paper suggests a facile fabrication strategy via electrospinning to develop a stretchable, and sensitive poly (vinylidene fluoride) nanofibrous strain sensor for human motion monitoring. A complete characterization on the single PVDF nano fiber has been performed. The charge generated by PVDF electrospun strain sensor changes was employed as a parameter to control the finger motion of the robotic arm. As a proof of concept, we developed a smart glove with five sensors integrated into it to detect the fingers motion and transfer it to a robotic hand. Our results shows that the proposed strain sensors are able to detect tiny motion of fingers and successfully run the robotic hand. PMID:29389851

Classification of EMG signals using artificial neural networks for virtual hand prosthesis control.

PubMed

Mattioli, Fernando E R; Lamounier, Edgard A; Cardoso, Alexandre; Soares, Alcimar B; Andrade, Adriano O

2011-01-01

Computer-based training systems have been widely studied in the field of human rehabilitation. In health applications, Virtual Reality presents itself as an appropriate tool to simulate training environments without exposing the patients to risks. In particular, virtual prosthetic devices have been used to reduce the great mental effort needed by patients fitted with myoelectric prosthesis, during the training stage. In this paper, the application of Virtual Reality in a hand prosthesis training system is presented. To achieve this, the possibility of exploring Neural Networks in a real-time classification system is discussed. The classification technique used in this work resulted in a 95% success rate when discriminating 4 different hand movements.

Evaluation of an eye-pointer interaction device for human-computer interaction.

PubMed

Cáceres, Enrique; Carrasco, Miguel; Ríos, Sebastián

2018-03-01

Advances in eye-tracking technology have led to better human-computer interaction, and involve controlling a computer without any kind of physical contact. This research describes the transformation of a commercial eye-tracker for use as an alternative peripheral device in human-computer interactions, implementing a pointer that only needs the eye movements of a user facing a computer screen, thus replacing the need to control the software by hand movements. The experiment was performed with 30 test individuals who used the prototype with a set of educational videogames. The results show that, although most of the test subjects would prefer a mouse to control the pointer, the prototype tested has an empirical precision similar to that of the mouse, either when trying to control its movements or when attempting to click on a point of the screen.

Impaired Communication Between the Motor and Somatosensory Homunculus Is Associated With Poor Manual Dexterity in Autism Spectrum Disorder.

PubMed

Thompson, Abigail; Murphy, Declan; Dell'Acqua, Flavio; Ecker, Christine; McAlonan, Grainne; Howells, Henrietta; Baron-Cohen, Simon; Lai, Meng-Chuan; Lombardo, Michael V

2017-02-01

Fine motor skill impairments are common in autism spectrum disorder (ASD), significantly affecting quality of life. Sensory inputs reaching the primary motor cortex (M1) from the somatosensory cortex (S1) are likely involved in fine motor skill and specifically motor learning. However, the role of these connections has not been directly investigated in humans. This study aimed to investigate, for the first time, the role of the S1-M1 connections in healthy subjects in vivo and whether microstructural alterations are associated with motor impairment in ASD. Sixty right-handed neurotypical adult men aged 18 to 45 years, and 60 right-handed age- and sex-matched subjects diagnosed with ASD underwent fine motor skill assessment and scanning with diffusion tensor imaging (DTI). The streamlines of the hand region connecting S1-M1 of the motor-sensory homunculus were virtually dissected using TrackVis, and diffusion properties were extracted. The face/tongue region connections were used as control tracts. The ASD group displayed lower motor performances and altered DTI measurements of the hand-region connection. Behavioral performance correlated with hand-region DTI measures in both groups, but not with the face/tongue connections, indicating anatomical specificity. There was a left-hemisphere association of motor ability in the control group and an atypical rightward shift in the ASD group. These findings suggest that direct interaction between S1 and M1 may contribute to the human ability to precisely interact with and manipulate the environment. Because electrophysiological evidence indicates that these connections may underpin long-term potentiation in M1, our findings may lead to novel therapeutic treatments for motor skill disorders. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

The Jet Propulsion Laboratory shared control architecture and implementation

NASA Technical Reports Server (NTRS)

Backes, Paul G.; Hayati, Samad

1990-01-01

A hardware and software environment for shared control of telerobot task execution has been implemented. Modes of task execution range from fully teleoperated to fully autonomous as well as shared where hand controller inputs from the human operator are mixed with autonomous system inputs in real time. The objective of the shared control environment is to aid the telerobot operator during task execution by merging real-time operator control from hand controllers with autonomous control to simplify task execution for the operator. The operator is the principal command source and can assign as much autonomy for a task as desired. The shared control hardware environment consists of two PUMA 560 robots, two 6-axis force reflecting hand controllers, Universal Motor Controllers for each of the robots and hand controllers, a SUN4 computer, and VME chassis containing 68020 processors and input/output boards. The operator interface for shared control, the User Macro Interface (UMI), is a menu driven interface to design a task and assign the levels of teleoperated and autonomous control. The operator also sets up the system monitor which checks safety limits during task execution. Cartesian-space degrees of freedom for teleoperated and/or autonomous control inputs are selected within UMI as well as the weightings for the teleoperation and autonmous inputs. These are then used during task execution to determine the mix of teleoperation and autonomous inputs. Some of the autonomous control primitives available to the user are Joint-Guarded-Move, Cartesian-Guarded-Move, Move-To-Touch, Pin-Insertion/Removal, Door/Crank-Turn, Bolt-Turn, and Slide. The operator can execute a task using pure teleoperation or mix control execution from the autonomous primitives with teleoperated inputs. Presently the shared control environment supports single arm task execution. Work is presently underway to provide the shared control environment for dual arm control. Teleoperation during shared control is only Cartesian space control and no force-reflection is provided. Force-reflecting teleoperation and joint space operator inputs are planned extensions to the environment.

Hand Grasping Synergies As Biometrics.

PubMed

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.

Early Pleistocene third metacarpal from Kenya and the evolution of modern human-like hand morphology

PubMed Central

Ward, Carol V.; Tocheri, Matthew W.; Plavcan, J. Michael; Brown, Francis H.; Manthi, Fredrick Kyalo

2014-01-01

Despite discoveries of relatively complete hands from two early hominin species (Ardipithecus ramidus and Australopithecus sediba) and partial hands from another (Australopithecus afarensis), fundamental questions remain about the evolution of human-like hand anatomy and function. These questions are driven by the paucity of hand fossils in the hominin fossil record between 800,000 and 1.8 My old, a time interval well documented for the emergence and subsequent proliferation of Acheulian technology (shaped bifacial stone tools). Modern and Middle to Late Pleistocene humans share a suite of derived features in the thumb, wrist, and radial carpometacarpal joints that is noticeably absent in early hominins. Here we show that one of the most distinctive features of this suite in the Middle Pleistocene to recent human hand, the third metacarpal styloid process, was present ∼1.42 Mya in an East African hominin from Kaitio, West Turkana, Kenya. This fossil thus provides the earliest unambiguous evidence for the evolution of a key shared derived characteristic of modern human and Neandertal hand morphology and suggests that the distinctive complex of radial carpometacarpal joint features in the human hand arose early in the evolution of the genus Homo and probably in Homo erectus sensu lato. PMID:24344276

A training platform for many-dimensional prosthetic devices using a virtual reality environment

PubMed Central

Putrino, David; Wong, Yan T.; Weiss, Adam; Pesaran, Bijan

2014-01-01

Brain machine interfaces (BMIs) have the potential to assist in the rehabilitation of millions of patients worldwide. Despite recent advancements in BMI technology for the restoration of lost motor function, a training environment to restore full control of the anatomical segments of an upper limb extremity has not yet been presented. Here, we develop a virtual upper limb prosthesis with 27 independent dimensions, the anatomical dimensions of the human arm and hand, and deploy the virtual prosthesis as an avatar in a virtual reality environment (VRE) that can be controlled in real-time. The prosthesis avatar accepts kinematic control inputs that can be captured from movements of the arm and hand as well as neural control inputs derived from processed neural signals. We characterize the system performance under kinematic control using a commercially available motion capture system. We also present the performance under kinematic control achieved by two non-human primates (Macaca Mulatta) trained to use the prosthetic avatar to perform reaching and grasping tasks. This is the first virtual prosthetic device that is capable of emulating all the anatomical movements of a healthy upper limb in real-time. Since the system accepts both neural and kinematic inputs for a variety of many-dimensional skeletons, we propose it provides a customizable training platform for the acquisition of many-dimensional neural prosthetic control. PMID:24726625

Adhesion and enrichment of metals on human hands from contaminated soil at an Arctic urban brownfield.

PubMed

Siciliano, Steven D; James, K; Zhang, Guiyin; Schafer, Alexis N; Peak, J Derek

2009-08-15

Human exposure to contaminated soils drives clean up criteria at many urban brownfields. Current risk assessment guidelines assume that humans ingest some fraction of soil smaller than 4 mm but have no estimates of what fraction of soil is ingested by humans. Here, we evaluated soil adherence to human hands for 13 agricultural soils from Saskatchewan, Canada and 17 different soils from a brownfield located in Iqaluit, Nunavut, Canada. In addition, we estimated average particle size adhering to human hands for residents of a northern urban setting. Further, we estimated how metal concentrations differed between the adhered and bulk (< 4 mm) fraction of soil. The average particle size for adhered agricultural soils was 34 microm, adhered brownfield soils was 105 microm, and particles adhered to human residentswas 36 microm. Metals were significantly enriched in these adhered fractions with an average enrichment [(adhered-bulk)/bulk] in metal concentration of 184% (113% median) for 24 different elements. Enrichment was greater for key toxicological elements of concern such as chromium (140%), copper (140%), nickel (130%), lead (110%), and zinc (130%) and was highest for silver (810%), mercury (630%), selenium (500%), and arsenic (420%). Enrichment were positively correlated with carbonate complexation constants (but not bulk solubility products) and suggests that the dominant mechanism controlling metal enrichment in these samples is a precipitation of carbonate surfaces that subsequently adsorb metals. Our results suggest that metals of toxicological concern are selectively enriched in the fraction of soil that humans incidentally ingest. Investigators should likely process soil samples through a 45 microm sieve before estimating the risk associated with contaminated soils to humans. The chemical mechanisms resulting in metal enrichment likely differ between sites but at our site were linked to surface complexation with carbonates.

Design and Evaluation of a Cable-Driven fMRI-Compatible Haptic Interface to Investigate Precision Grip Control

PubMed Central

Vigaru, Bogdan; Sulzer, James; Gassert, Roger

2016-01-01

Our hands and fingers are involved in almost all activities of daily living and, as such, have a disproportionately large neural representation. Functional magnetic resonance imaging investigations into the neural control of the hand have revealed great advances, but the harsh MRI environment has proven to be a challenge to devices capable of delivering a large variety of stimuli necessary for well-controlled studies. This paper presents a fMRI-compatible haptic interface to investigate the neural mechanisms underlying precision grasp control. The interface, located at the scanner bore, is controlled remotely through a shielded electromagnetic actuation system positioned at the end of the scanner bed and then through a high stiffness, low inertia cable transmission. We present the system design, taking into account requirements defined by the biomechanics and dynamics of the human hand, as well as the fMRI environment. Performance evaluation revealed a structural stiffness of 3.3 N/mm, renderable forces up to 94 N, and a position control bandwidth of at least 19 Hz. MRI-compatibility tests showed no degradation in the operation of the haptic interface or the image quality. A preliminary fMRI experiment during a pilot study validated the usability of the haptic interface, illustrating the possibilities offered by this device. PMID:26441454

A Brain-Machine Interface Based on ERD/ERS for an Upper-Limb Exoskeleton Control.

PubMed

Tang, Zhichuan; Sun, Shouqian; Zhang, Sanyuan; Chen, Yumiao; Li, Chao; Chen, Shi

2016-12-02

To recognize the user's motion intention, brain-machine interfaces (BMI) usually decode movements from cortical activity to control exoskeletons and neuroprostheses for daily activities. The aim of this paper is to investigate whether self-induced variations of the electroencephalogram (EEG) can be useful as control signals for an upper-limb exoskeleton developed by us. A BMI based on event-related desynchronization/synchronization (ERD/ERS) is proposed. In the decoder-training phase, we investigate the offline classification performance of left versus right hand and left hand versus both feet by using motor execution (ME) or motor imagery (MI). The results indicate that the accuracies of ME sessions are higher than those of MI sessions, and left hand versus both feet paradigm achieves a better classification performance, which would be used in the online-control phase. In the online-control phase, the trained decoder is tested in two scenarios (wearing or without wearing the exoskeleton). The MI and ME sessions wearing the exoskeleton achieve mean classification accuracy of 84.29% ± 2.11% and 87.37% ± 3.06%, respectively. The present study demonstrates that the proposed BMI is effective to control the upper-limb exoskeleton, and provides a practical method by non-invasive EEG signal associated with human natural behavior for clinical applications.

Decoding of human hand actions to handle missing limbs in neuroprosthetics.

PubMed

Belić, Jovana J; Faisal, A Aldo

2015-01-01

The only way we can interact with the world is through movements, and our primary interactions are via the hands, thus any loss of hand function has immediate impact on our quality of life. However, to date it has not been systematically assessed how coordination in the hand's joints affects every day actions. This is important for two fundamental reasons. Firstly, to understand the representations and computations underlying motor control "in-the-wild" situations, and secondly to develop smarter controllers for prosthetic hands that have the same functionality as natural limbs. In this work we exploit the correlation structure of our hand and finger movements in daily-life. The novelty of our idea is that instead of averaging variability out, we take the view that the structure of variability may contain valuable information about the task being performed. We asked seven subjects to interact in 17 daily-life situations, and quantified behavior in a principled manner using CyberGlove body sensor networks that, after accurate calibration, track all major joints of the hand. Our key findings are: (1) We confirmed that hand control in daily-life tasks is very low-dimensional, with four to five dimensions being sufficient to explain 80-90% of the variability in the natural movement data. (2) We established a universally applicable measure of manipulative complexity that allowed us to measure and compare limb movements across tasks. We used Bayesian latent variable models to model the low-dimensional structure of finger joint angles in natural actions. (3) This allowed us to build a naïve classifier that within the first 1000 ms of action initiation (from a flat hand start configuration) predicted which of the 17 actions was going to be executed-enabling us to reliably predict the action intention from very short-time-scale initial data, further revealing the foreseeable nature of hand movements for control of neuroprosthetics and tele operation purposes. (4) Using the Expectation-Maximization algorithm on our latent variable model permitted us to reconstruct with high accuracy (<5-6° MAE) the movement trajectory of missing fingers by simply tracking the remaining fingers. Overall, our results suggest the hypothesis that specific hand actions are orchestrated by the brain in such a way that in the natural tasks of daily-life there is sufficient redundancy and predictability to be directly exploitable for neuroprosthetics.

Models to teach lung sonopathology and ultrasound-guided thoracentesis.

PubMed

Wojtczak, Jacek A

2014-12-01

Lung sonography allows rapid diagnosis of lung emergencies such as pulmonary edema, hemothorax or pneumothorax. The ability to timely diagnose an intraoperative pneumothorax is an important skill for the anesthesiologist. However, lung ultrasound exams require an interpretation of not only real images but also complex acoustic artifacts such as A-lines and B-lines. Therefore, appropriate training to gain proficiency is important. Simulated environment using ultrasound phantom models allows controlled, supervised learning. We have developed hybrid models that combine dry or wet polyurethane foams, porcine rib cages and human hand simulating a rib cage. These models simulate fairly accurately pulmonary sonopathology and allow supervised teaching of lung sonography with the immediate feedback. In-vitro models can also facilitate learning of procedural skills, improving transducer and needle positioning and movement, rapid recognition of thoracic anatomy and hand - eye coordination skills. We described a new model to teach an ultrasound guided thoracentesis. This model consists of the experimenter's hand placed on top of the water-filled container with a wet foam. Metacarpal bones of the human hand simulate a rib cage and a wet foam simulates a diseased lung immersed in the pleural fluid. Positive fluid flow offers users feedback when a simulated pleural effusion is accurately assessed.

Design and fabrication of robotic gripper for grasping in minimizing contact force

NASA Astrophysics Data System (ADS)

Heidari, Hamidreza; Pouria, Milad Jafary; Sharifi, Shahriar; Karami, Mahmoudreza

2018-03-01

This paper presents a new method to improve the kinematics of robot gripper for grasping in unstructured environments, such as space operations. The robot gripper is inspired from the human hand and kept the hand design close to the structure of human fingers to provide successful grasping capabilities. The main goal is to improve kinematic structure of gripper to increase the grasping capability of large objects, decrease the contact forces and makes a successful grasp of various objects in unstructured environments. This research will describe the development of a self-adaptive and reconfigurable robotic hand for space operations through mechanical compliance which is versatile, robust and easy to control. Our model contains two fingers, two-link and three-link, with combining a kinematic model of thumb index. Moreover, some experimental tests are performed to examine the effectiveness of the hand-made in real, unstructured tasks. The results represent that the successful grasp range is improved about 30% and the contact forces is reduced approximately 10% for a wide range of target object size. According to the obtained results, the proposed approach provides an accommodative kinematic model which makes the better grasping capability by fingers geometries for a robot gripper.

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

NASA Astrophysics Data System (ADS)

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.

Fabrication, sensation and control of fluidic elastomer actuators and their application towards hand orthotics and prosthetics

NASA Astrophysics Data System (ADS)

Zhao, Huichan

Due to their continuous and natural motion, fluidic elastomer actuators (FEAs) have shown potential in a range of robotic applications including prosthetics and orthotics. Despite their advantages and rapid developments, robots using these actuators still have several challenging issues to be addressed. First, the reliable production of low cost and complex actuators that can apply high forces is necessary, yet none of existing fabrication methods are both easy to implement and of high force output. Next, compliant or stretchable sensors that can be embedded into their bodies for sophisticated functions are required, however, many of these sensors suffer from hysteresis, fabrication complexity, chemical safety and environmental instability, and material incompatibility with soft actuators. Finally, feedback control for FEAs is necessary to achieve better performance, but most soft robots are still "open-loop". In this dissertation, I intend to help solve the above issues and drive the applications of soft robotics towards hand orthotics and prosthetics. First, I adapt rotational casting as a new manufacturing method for soft actuators. I present a cuboid soft actuator that can generate a force of >25 N at its tip, a near ten-fold increase over similar actuators previously reported. Next, I propose a soft orthotic finger with position control enabled via embedded optical fiber. I monitor both the static and dynamic states via the optical sensor and achieve the prescribed curvatures accurately and with stability by a gain-scheduled proportional-integral-derivative controller. Then I develop the soft orthotic fingers into a low-cost, closed-loop controlled, soft orthotic glove that can be worn by a typical human hand and helpful for grasping light objects, while also providing finger position control. I achieve motion control with inexpensive, binary pneumatic switches controlled by a simple finite-state-machine. Finally, I report the first use of stretchable optical waveguides for strain sensing in a soft prosthetic hand. These optoelectronic strain sensors are easy to fabricate, chemically inert, and demonstrate low hysteresis and high precision in their output signals. I use the optoelectronically innervated prosthetic hand to conduct various active sensation experiments inspired by the capabilities of a real hand.

A neural interface provides long-term stable natural touch perception.

PubMed

Tan, Daniel W; Schiefer, Matthew A; Keith, Michael W; Anderson, James Robert; Tyler, Joyce; Tyler, Dustin J

2014-10-08

Touch perception on the fingers and hand is essential for fine motor control, contributes to our sense of self, allows for effective communication, and aids in our fundamental perception of the world. Despite increasingly sophisticated mechatronics, prosthetic devices still do not directly convey sensation back to their wearers. We show that implanted peripheral nerve interfaces in two human subjects with upper limb amputation provided stable, natural touch sensation in their hands for more than 1 year. Electrical stimulation using implanted peripheral nerve cuff electrodes that did not penetrate the nerve produced touch perceptions at many locations on the phantom hand with repeatable, stable responses in the two subjects for 16 and 24 months. Patterned stimulation intensity produced a sensation that the subjects described as natural and without "tingling," or paresthesia. Different patterns produced different types of sensory perception at the same location on the phantom hand. The two subjects reported tactile perceptions they described as natural tapping, constant pressure, light moving touch, and vibration. Changing average stimulation intensity controlled the size of the percept area; changing stimulation frequency controlled sensation strength. Artificial touch sensation improved the subjects' ability to control grasping strength of the prosthesis and enabled them to better manipulate delicate objects. Thus, electrical stimulation through peripheral nerve electrodes produced long-term sensory restoration after limb loss. Copyright © 2014, American Association for the Advancement of Science.

A neural interface provides long-term stable natural touch perception

PubMed Central

Tan, Daniel W.; Schiefer, Matthew A.; Keith, Michael W.; Anderson, James Robert; Tyler, Joyce; Tyler, Dustin J.

2017-01-01

Touch perception on the fingers and hand is essential for fine motor control, contributes to our sense of self, allows for effective communication, and aids in our fundamental perception of the world. Despite increasingly sophisticated mechatronics, prosthetic devices still do not directly convey sensation back to their wearers. We show that implanted peripheral nerve interfaces in two human subjects with upper limb amputation provided stable, natural touch sensation in their hands for more than 1 year. Electrical stimulation using implanted peripheral nerve cuff electrodes that did not penetrate the nerve produced touch perceptions at many locations on the phantom hand with repeatable, stable responses in the two subjects for 16 and 24 months. Patterned stimulation intensity produced a sensation that the subjects described as natural and without “tingling,” or paresthesia. Different patterns produced different types of sensory perception at the same location on the phantom hand. The two subjects reported tactile perceptions they described as natural tapping, constant pressure, light moving touch, and vibration. Changing average stimulation intensity controlled the size of the percept area; changing stimulation frequency controlled sensation strength. Artificial touch sensation improved the subjects’ ability to control grasping strength of the prosthesis and enabled them to better manipulate delicate objects. Thus, electrical stimulation through peripheral nerve electrodes produced long-term sensory restoration after limb loss. PMID:25298320

Dissociable neural responses to hands and non-hand body parts in human left extrastriate visual cortex.

PubMed

Bracci, Stefania; Ietswaart, Magdalena; Peelen, Marius V; Cavina-Pratesi, Cristiana

2010-06-01

Accumulating evidence points to a map of visual regions encoding specific categories of objects. For example, a region in the human extrastriate visual cortex, the extrastriate body area (EBA), has been implicated in the visual processing of bodies and body parts. Although in the monkey, neurons selective for hands have been reported, in humans it is unclear whether areas selective for individual body parts such as the hand exist. Here, we conducted two functional MRI experiments to test for hand-preferring responses in the human extrastriate visual cortex. We found evidence for a hand-preferring region in left lateral occipitotemporal cortex in all 14 participants. This region, located in the lateral occipital sulcus, partially overlapped with left EBA, but could be functionally and anatomically dissociated from it. In experiment 2, we further investigated the functional profile of hand- and body-preferring regions by measuring responses to hands, fingers, feet, assorted body parts (arms, legs, torsos), and non-biological handlike stimuli such as robotic hands. The hand-preferring region responded most strongly to hands, followed by robotic hands, fingers, and feet, whereas its response to assorted body parts did not significantly differ from baseline. By contrast, EBA responded most strongly to body parts, followed by hands and feet, and did not significantly respond to robotic hands or fingers. Together, these results provide evidence for a representation of the hand in extrastriate visual cortex that is distinct from the representation of other body parts.

Dissociable Neural Responses to Hands and Non-Hand Body Parts in Human Left Extrastriate Visual Cortex

PubMed Central

Ietswaart, Magdalena; Peelen, Marius V.; Cavina-Pratesi, Cristiana

2010-01-01

Accumulating evidence points to a map of visual regions encoding specific categories of objects. For example, a region in the human extrastriate visual cortex, the extrastriate body area (EBA), has been implicated in the visual processing of bodies and body parts. Although in the monkey, neurons selective for hands have been reported, in humans it is unclear whether areas selective for individual body parts such as the hand exist. Here, we conducted two functional MRI experiments to test for hand-preferring responses in the human extrastriate visual cortex. We found evidence for a hand-preferring region in left lateral occipitotemporal cortex in all 14 participants. This region, located in the lateral occipital sulcus, partially overlapped with left EBA, but could be functionally and anatomically dissociated from it. In experiment 2, we further investigated the functional profile of hand- and body-preferring regions by measuring responses to hands, fingers, feet, assorted body parts (arms, legs, torsos), and non-biological handlike stimuli such as robotic hands. The hand-preferring region responded most strongly to hands, followed by robotic hands, fingers, and feet, whereas its response to assorted body parts did not significantly differ from baseline. By contrast, EBA responded most strongly to body parts, followed by hands and feet, and did not significantly respond to robotic hands or fingers. Together, these results provide evidence for a representation of the hand in extrastriate visual cortex that is distinct from the representation of other body parts. PMID:20393066

The history of scabies in veterinary and human medicine from biblical to modern times.

PubMed

Roncalli, R A

1987-07-01

For many centuries a host of naturalists, savants, physicians and veterinarians have tried to unravel the etiology of scabies in humans and animals and to discover effective remedies to control it. After many attempts, success was achieved in the discovery of the parasitic etiology of the disease in the 15th century. Also, major advances with regard to the treatment of the disease were made during the 19th and 20th centuries. Today the prevalence of epidemic scabies in humans has diminished; on the other hand, good progress in the control of mange of livestock has been made only in a few countries including Australia, New Zealand and the U.S.A.

The Significance of the Hand for the Elementary Years

ERIC Educational Resources Information Center

Baker, Kay

2013-01-01

The use of the hand is a physiological sequence. The prehensile nature of the human hand is an evolutionary feature as is the freeing of the hands due to bipedalism. Kay Baker outlines of the human hand's significance to the mind as found in chapter 14 of the "Absorbent Mind." In this article, she has created lists that break down the…

Efficacy of alcohols and alcohol-based hand disinfectants against human enterovirus 71.

PubMed

Chang, S-C; Li, W-C; Huang, K-Y; Huang, Y-C; Chiu, C-H; Chen, C-J; Hsieh, Y-C; Kuo, C-Y; Shih, S-R; Lin, T-Y

2013-04-01

Human enterovirus 71 (HEV71) infections are a significant public health threat in the Asia-Pacific region and occasionally cause severe neurological complications and even death in children. Although good hand hygiene is important for controlling infection, relevant data regarding the efficacy of widely used hand disinfectants against HEV71 are still lacking. To investigate the virucidal activity of alcohols and alcohol-based hand disinfectants against HEV71. A common alcohol-based hand disinfectant (0.5% chlorhexidine gluconate + 70% isopropanol) as well as different concentrations of isopropanol and ethanol were tested for virucidal activity against HEV71 using the suspension and the fingerpad tests. In suspension tests, 85% and 95% ethanol achieved a mean log10 reduction factor in HEV71 titre of >3 and nearly 6, respectively, within 10 min. By contrast, 70% and 75% ethanol and any concentration of isopropanol (70-95%) produced a factor of <1 in this test after the same exposure time. In fingerpad tests, only 95% ethanol showed a mean log10 reduction factor of >4, while both 75% ethanol and a chlorhexidine gluconate-containing formula were ineffective against HEV71 with a mean log10 reduction factor of <1 after a 30 s exposure time. Widely used alcohol-based hand disinfectants based on 70% ethanol or isopropanol have poor effectiveness against HEV71. Ninety-five percent ethanol is the most effective concentration, but still cannot fully inactivate HEV71 and may be impractical for use in many instances. Hand hygiene with alcohol-based hand disinfectants alone is not recommended for preventing HEV71 transmission. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Ego-rotation and object-rotation in major depressive disorder.

PubMed

Chen, Jiu; Yang, Laiqi; Ma, Wentao; Wu, Xingqu; Zhang, Yan; Wei, Dunhong; Liu, Guangxiong; Deng, Zihe; Hua, Zhen; Jia, Ting

2013-08-30

Mental rotation (MR) performance provides a direct insight into a prototypical higher-level visuo-spatial cognitive operation. Previous studies suggest that progressive slowing with an increasing angle of orientation indicates a specific wing of object-based mental transformations in the psychomotor retardation that occurs in major depressive disorder (MDD). It is still not known, however, whether the ability of object-rotation is associated with the ability of ego-rotation in MDD. The present study was designed to investigate the level of impairment of mental transformation abilities in MDD. For this purpose we tested 33 MDD (aged 18-52 years, 16 women) and 30 healthy control subjects (15 women, age and education matched) by evaluating the performance of MDD subjects with regard to ego-rotation and object-rotation tasks. First, MDD subjects were significantly slower and made more errors than controls in mentally rotating hands and letters. Second, MDD and control subjects displayed the same pattern of response times to stimuli at various orientations in the letter task but not the hand task. Third, in particular, MDD subjects were significantly slower and made more errors during the mental transformation of hands than letters relative to control subjects and were significantly slower and made more errors in physiologically impossible angles than physiologically possible angles in the mental rotation hand task. In conclusion, MDD subjects present with more serious mental rotation deficits specific to the hand than the letter task. Importantly, deficits were more present during the mental transformation in outward rotation angles, thus suggesting that the mental imagery for hands and letters relies on different processing mechanisms which suggest a module that is more complex for the processing of human hands than for letters during mental rotation tasks. Our study emphasises the necessity of distinguishing different levels of impairment of action in MDD subjects. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Hand Controller Assembly

NASA Technical Reports Server (NTRS)

Bandera, Pablo (Inventor); Buchele, Paul (Inventor)

2015-01-01

A user input device for a vehicular electrical system is provided. The user input device includes a handle sized and shaped to be gripped by a human hand and a gimbal assembly within the handle. The gimbal assembly includes a first gimbal component, a second gimbal component coupled to the first gimbal component such that the second gimbal component is rotatable relative to the first gimbal component about a first axis, and a third gimbal component coupled to the second gimbal component such that the third gimbal component is rotatable relative to the second gimbal component about a second axis.

Hands-Free Control Interfaces for an Extra Vehicular Jetpack

NASA Technical Reports Server (NTRS)

Zumbado, Jennifer Rochlis; Curiel, Pedro H.; Schreiner, Sam

2012-01-01

The National Aeronautics and Space Administration (NASA) strategic vision includes, as part of its long-term goals, the exploration of deep space and Near Earth Asteroids (NEA). To support these endeavors, funds have been invested in research to develop advanced exploration capabilities. To enable the human mobility necessary to effectively explore NEA and deep space, a new extravehicular activity (EVA) Jetpack is under development at the Johnson Space Center. The new design leverages knowledge and experience gained from the current astronaut rescue device, the Simplified Aid for EVA Rescue (SAFER). Whereas the primary goal for a rescue device is to return the crew to a safe haven, in-space exploration and navigation requires an expanded set of capabilities. To accommodate the range of tasks astronauts may be expected to perform while utilizing the Jetpack, it was desired to offer a hands-free method of control. This paper describes the development and innovations involved in creating two hands-free control interfaces and an experimental test platform for a suited astronaut flying the Jetpack during an EVA.

Illusory movement perception improves motor control for prosthetic hands.

PubMed

Marasco, Paul D; Hebert, Jacqueline S; Sensinger, Jon W; Shell, Courtney E; Schofield, Jonathon S; Thumser, Zachary C; Nataraj, Raviraj; Beckler, Dylan T; Dawson, Michael R; Blustein, Dan H; Gill, Satinder; Mensh, Brett D; Granja-Vazquez, Rafael; Newcomb, Madeline D; Carey, Jason P; Orzell, Beth M

2018-03-14

To effortlessly complete an intentional movement, the brain needs feedback from the body regarding the movement's progress. This largely nonconscious kinesthetic sense helps the brain to learn relationships between motor commands and outcomes to correct movement errors. Prosthetic systems for restoring function have predominantly focused on controlling motorized joint movement. Without the kinesthetic sense, however, these devices do not become intuitively controllable. We report a method for endowing human amputees with a kinesthetic perception of dexterous robotic hands. Vibrating the muscles used for prosthetic control via a neural-machine interface produced the illusory perception of complex grip movements. Within minutes, three amputees integrated this kinesthetic feedback and improved movement control. Combining intent, kinesthesia, and vision instilled participants with a sense of agency over the robotic movements. This feedback approach for closed-loop control opens a pathway to seamless integration of minds and machines. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Following the Hand: The First Three Years of Life.

ERIC Educational Resources Information Center

Orion, Judy

2001-01-01

Discusses the development of the human hand from birth to age three as it contributes to the formation of human personality. Considers how parallels in eye, hand, brain, and motor skill development portray the evolving complexity and adaptation of the human grasp and illustrate Montessori theories about the relationship between physical experience…

Human-arm-and-hand-dynamic model with variability analyses for a stylus-based haptic interface.

PubMed

Fu, Michael J; Cavuşoğlu, M Cenk

2012-12-01

Haptic interface research benefits from accurate human arm models for control and system design. The literature contains many human arm dynamic models but lacks detailed variability analyses. Without accurate measurements, variability is modeled in a very conservative manner, leading to less than optimal controller and system designs. This paper not only presents models for human arm dynamics but also develops inter- and intrasubject variability models for a stylus-based haptic device. Data from 15 human subjects (nine male, six female, ages 20-32) were collected using a Phantom Premium 1.5a haptic device for system identification. In this paper, grip-force-dependent models were identified for 1-3-N grip forces in the three spatial axes. Also, variability due to human subjects and grip-force variation were modeled as both structured and unstructured uncertainties. For both forms of variability, the maximum variation, 95 %, and 67 % confidence interval limits were examined. All models were in the frequency domain with force as input and position as output. The identified models enable precise controllers targeted to a subset of possible human operator dynamics.

Short Term Motor-Skill Acquisition Improves with Size of Self-Controlled Virtual Hands

PubMed Central

Ossmy, Ori; Mukamel, Roy

2017-01-01

Visual feedback in general, and from the body in particular, is known to influence the performance of motor skills in humans. However, it is unclear how the acquisition of motor skills depends on specific visual feedback parameters such as the size of performing effector. Here, 21 healthy subjects physically trained to perform sequences of finger movements with their right hand. Through the use of 3D Virtual Reality devices, visual feedback during training consisted of virtual hands presented on the screen, tracking subject’s hand movements in real time. Importantly, the setup allowed us to manipulate the size of the displayed virtual hands across experimental conditions. We found that performance gains increase with the size of virtual hands. In contrast, when subjects trained by mere observation (i.e., in the absence of physical movement), manipulating the size of the virtual hand did not significantly affect subsequent performance gains. These results demonstrate that when it comes to short-term motor skill learning, the size of visual feedback matters. Furthermore, these results suggest that highest performance gains in individual subjects are achieved when the size of the virtual hand matches their real hand size. These results may have implications for optimizing motor training schemes. PMID:28056023

Anterior wrist and medial malleolus as the novel sites of tissue selection: a retrospective study on electric shock death through the hand-to-foot circuit pathway.

PubMed

Xu, Guangtao; Su, Ruibing; Lv, Junyao; Hu, Bo; Gu, Huan; Li, Xianxian; Gu, Jiang; Yu, Xiaojun

2017-05-01

Our previous work demonstrated that characteristic changes could occur in the anterior wrist and medial malleolus in electric deaths through the hand-to-foot electric circuit pathway in an electric shock rat model. However, whether the same phenomenon occurs in humans is unknown. The aim of the present retrospective study was to ascertain whether the anterior wrist and medial malleolus could also be selected as the promising and significant sites in electric death through the hand-to-foot circuit pathway. Nineteen human cases from the autopsy and one clinical survivor who sustained a severe electric shock through the hand-to-foot circuit pathway were analyzed. Additional ten autopsy patients who died from traffic accidents and sudden cardiac attacks were used as the control group. Histopathological changes in the soft tissues of the anterior wrist and medial malleolus in all autopsy patients, as well as the electric current pathway of the survivor, were observed. The results showed that the nuclear polarizations in the anterior wrist and medial malleolus soft tissues of the electric death were extremely noticeable as compared with the controls. The most severe electrical injury in the survivor occurred in the anterior wrist. These findings suggest that the soft tissues of the anterior wrist and/or the medial malleolus as the narrowest parts of the limbs could be used as the complementary sites for tissue selection and considered as necessary locations for examinations to assess the electric death in medicolegal identification.

Subsystems of sensory attention for skilled reaching: vision for transport and pre-shaping and somatosensation for grasping, withdrawal and release.

PubMed

Sacrey, Lori-Ann R; Whishaw, Ian Q

2012-06-01

Skilled reaching is a forelimb movement in which a subject reaches for a piece of food that is placed in the mouth for eating. It is a natural movement used by many animal species and is a routine, daily activity for humans. Its prominent features include transport of the hand to a target, shaping the digits in preparation for grasping, grasping, and withdrawal of the hand to place the food in the mouth. Studies on normal human adults show that skilled reaching is mediated by at least two sensory attention processes. Hand transport to the target and hand shaping are temporally coupled with visual fixation on the target. Grasping, withdrawal, and placing the food into the mouth are associated with visual disengagement and somatosensory guidance. Studies on nonhuman animal species illustrate that shared visual and somatosensory attention likely evolved in the primate lineage. Studies on developing infants illustrate that shared attention requires both experience and maturation. Studies on subjects with Parkinson's disease and Huntington's disease illustrate that decomposition of shared attention also features compensatory visual guidance. The evolutionary, developmental, and neural control of skilled reaching suggests that associative learning processes are importantly related to normal adult attention sharing and so can be used in remediation. The economical use of sensory attention in the different phases of skilled reaching ensures efficiency in eating, reduces sensory interference between sensory reference frames, and provides efficient neural control of the advance and withdrawal components of skilled reaching movements. Copyright © 2011 Elsevier B.V. All rights reserved.

Hand Path Priming in Manual Obstacle Avoidance: Evidence that the Dorsal Stream Does Not Only Control Visually Guided Actions in Real Time

ERIC Educational Resources Information Center

Jax, Steven A.; Rosenbaum, David A.

2007-01-01

According to a prominent theory of human perception and performance (M. A. Goodale & A. D. Milner, 1992), the dorsal, action-related stream only controls visually guided actions in real time. Such a system would be predicted to show little or no action priming from previous experience. The 3 experiments reported here were designed to determine…

Humanizing Instructional Videos in Physics: When Less Is More

NASA Astrophysics Data System (ADS)

Schroeder, Noah L.; Traxler, Adrienne L.

2017-06-01

Many instructors in science, technology, engineering, and mathematics fields are striving to create active learning environments in their classrooms and in doing so are frequently moving the lecture portion of their course into online video format. In this classroom-based study, we used a two group randomized experimental design to examine the efficacy of an instructional video that incorporates a human hand demonstrating and modeling how to solve frictional inclined plane problems compared to an identical video that did not include the human hand. The results show that the learners who viewed the video without the human hand present performed significantly better on a learning test and experienced a significantly better training efficiency than the learners who viewed the video with the human hand present. Meanwhile, those who learned with the human hand present in the instructional video rated the instructor as being more humanlike and engaging. The results have implications for both theory and practice. Implications for those designing instructional videos are discussed, as well as the limitations of the current study.

Hand Grasping Synergies As Biometrics

PubMed Central

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. PMID:28512630

Decoding Individual Finger Movements from One Hand Using Human EEG Signals

PubMed Central

Gonzalez, Jania; Ding, Lei

2014-01-01

Brain computer interface (BCI) is an assistive technology, which decodes neurophysiological signals generated by the human brain and translates them into control signals to control external devices, e.g., wheelchairs. One problem challenging noninvasive BCI technologies is the limited control dimensions from decoding movements of, mainly, large body parts, e.g., upper and lower limbs. It has been reported that complicated dexterous functions, i.e., finger movements, can be decoded in electrocorticography (ECoG) signals, while it remains unclear whether noninvasive electroencephalography (EEG) signals also have sufficient information to decode the same type of movements. Phenomena of broadband power increase and low-frequency-band power decrease were observed in EEG in the present study, when EEG power spectra were decomposed by a principal component analysis (PCA). These movement-related spectral structures and their changes caused by finger movements in EEG are consistent with observations in previous ECoG study, as well as the results from ECoG data in the present study. The average decoding accuracy of 77.11% over all subjects was obtained in classifying each pair of fingers from one hand using movement-related spectral changes as features to be decoded using a support vector machine (SVM) classifier. The average decoding accuracy in three epilepsy patients using ECoG data was 91.28% with the similarly obtained features and same classifier. Both decoding accuracies of EEG and ECoG are significantly higher than the empirical guessing level (51.26%) in all subjects (p<0.05). The present study suggests the similar movement-related spectral changes in EEG as in ECoG, and demonstrates the feasibility of discriminating finger movements from one hand using EEG. These findings are promising to facilitate the development of BCIs with rich control signals using noninvasive technologies. PMID:24416360

Photonic Microhand with Autonomous Action.

PubMed

Martella, Daniele; Nocentini, Sara; Nuzhdin, Dmitry; Parmeggiani, Camilla; Wiersma, Diederik S

2017-11-01

Grabbing and holding objects at the microscale is a complex function, even for microscopic living animals. Inspired by the hominid-type hand, a microscopic equivalent able to catch microelements is engineered. This microhand is light sensitive and can be either remotely controlled by optical illumination or can act autonomously and grab small particles on the basis of their optical properties. Since the energy is delivered optically, without the need for wires or batteries, the artificial hand can be shrunk down to the micrometer scale. Soft material is used, in particular, a custom-made liquid-crystal network that is patterned by a photolithographic technique. The elastic reshaping properties of this material allow finger movement, using environmental light as the only energy source. The hand can be either controlled externally (via the light field), or else the conditions in which it autonomously grabs a particle in its vicinity can be created. This microrobot has the unique feature that it can distinguish between particles of different colors and gray levels. The realization of this autonomous hand constitutes a crucial element in the development of microscopic creatures that can perform tasks without human intervention and self-organized automation at the micrometer scale. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Somato-Motor Haptic Processing in Posterior Inner Perisylvian Region (SII/pIC) of the Macaque Monkey

PubMed Central

Ishida, Hiroaki; Fornia, Luca; Grandi, Laura Clara; Umiltà, Maria Alessandra; Gallese, Vittorio

2013-01-01

The posterior inner perisylvian region including the secondary somatosensory cortex (area SII) and the adjacent region of posterior insular cortex (pIC) has been implicated in haptic processing by integrating somato-motor information during hand-manipulation, both in humans and in non-human primates. However, motor-related properties during hand-manipulation are still largely unknown. To investigate a motor-related activity in the hand region of SII/pIC, two macaque monkeys were trained to perform a hand-manipulation task, requiring 3 different grip types (precision grip, finger exploration, side grip) both in light and in dark conditions. Our results showed that 70% (n = 33/48) of task related neurons within SII/pIC were only activated during monkeys’ active hand-manipulation. Of those 33 neurons, 15 (45%) began to discharge before hand-target contact, while the remaining neurons were tonically active after contact. Thirty-percent (n = 15/48) of studied neurons responded to both passive somatosensory stimulation and to the motor task. A consistent percentage of task-related neurons in SII/pIC was selectively activated during finger exploration (FE) and precision grasping (PG) execution, suggesting they play a pivotal role in control skilled finger movements. Furthermore, hand-manipulation-related neurons also responded when visual feedback was absent in the dark. Altogether, our results suggest that somato-motor neurons in SII/pIC likely contribute to haptic processing from the initial to the final phase of grasping and object manipulation. Such motor-related activity could also provide the somato-motor binding principle enabling the translation of diachronic somatosensory inputs into a coherent image of the explored object. PMID:23936121

Concealing of facial expressions by a wild Barbary macaque (Macaca sylvanus).

PubMed

Thunström, Maria; Kuchenbuch, Paul; Young, Christopher

2014-07-01

Behavioural research on non-vocal communication among non-human primates and its possible links to the origin of human language is a long-standing research topic. Because human language is under voluntary control, it is of interest whether this is also true for any communicative signals of other species. It has been argued that the behaviour of hiding a facial expression with one's hand supports the idea that gestures might be under more voluntary control than facial expressions among non-human primates, and it has also been interpreted as a sign of intentionality. So far, the behaviour has only been reported twice, for single gorilla and chimpanzee individuals, both in captivity. Here, we report the first observation of concealing of facial expressions by a monkey, a Barbary macaque (Macaca sylvanus), living in the wild. On eight separate occasions between 2009 and 2011 an adult male was filmed concealing two different facial expressions associated with play and aggression ("play face" and "scream face"), 22 times in total. The videos were analysed in detail, including gaze direction, hand usage, duration, and individuals present. This male was the only individual in his group to manifest this behaviour, which always occurred in the presence of a dominant male. Several possible interpretations of the function of the behaviour are discussed. The observations in this study indicate that the gestural communication and cognitive abilities of monkeys warrant more research attention.

Enteric pathogens in stored drinking water and on caregiver's hands in Tanzanian households with and without reported cases of child diarrhea.

PubMed

Mattioli, Mia Catharine; Boehm, Alexandria B; Davis, Jennifer; Harris, Angela R; Mrisho, Mwifadhi; Pickering, Amy J

2014-01-01

Diarrhea is one of the leading causes of mortality in young children. Diarrheal pathogens are transmitted via the fecal-oral route, and for children the majority of this transmission is thought to occur within the home. However, very few studies have documented enteric pathogens within households of low-income countries. The presence of molecular markers for three enteric viruses (enterovirus, adenovirus, and rotavirus), seven Escherichia coli virulence genes (ECVG), and human-specific Bacteroidales was assessed in hand rinses and household stored drinking water in Bagamoyo, Tanzania. Using a matched case-control study design, we examined the relationship between contamination of hands and water with these markers and child diarrhea. We found that the presence of ECVG in household stored water was associated with a significant decrease in the odds of a child within the home having diarrhea (OR = 0.51; 95% confidence interval 0.27-0.93). We also evaluated water management and hygiene behaviors. Recent hand contact with water or food was positively associated with detection of enteric pathogen markers on hands, as was relatively lower volumes of water reportedly used for daily hand washing. Enteropathogen markers in stored drinking water were more likely found among households in which the markers were also detected on hands, as well as in households with unimproved water supply and sanitation infrastructure. The prevalence of enteric pathogen genes and the human-specific Bacteroidales fecal marker in stored water and on hands suggests extensive environmental contamination within homes both with and without reported child diarrhea. Better stored water quality among households with diarrhea indicates caregivers with sick children may be more likely to ensure safe drinking water in the home. Interventions to increase the quantity of water available for hand washing, and to improve food hygiene, may reduce exposure to enteric pathogens in the domestic environment.

Enteric Pathogens in Stored Drinking Water and on Caregiver’s Hands in Tanzanian Households with and without Reported Cases of Child Diarrhea

PubMed Central

Mattioli, Mia Catharine; Boehm, Alexandria B.; Davis, Jennifer; Harris, Angela R.; Mrisho, Mwifadhi; Pickering, Amy J.

2014-01-01

Background Diarrhea is one of the leading causes of mortality in young children. Diarrheal pathogens are transmitted via the fecal-oral route, and for children the majority of this transmission is thought to occur within the home. However, very few studies have documented enteric pathogens within households of low-income countries. Methods and Findings The presence of molecular markers for three enteric viruses (enterovirus, adenovirus, and rotavirus), seven Escherichia coli virulence genes (ECVG), and human-specific Bacteroidales was assessed in hand rinses and household stored drinking water in Bagamoyo, Tanzania. Using a matched case-control study design, we examined the relationship between contamination of hands and water with these markers and child diarrhea. We found that the presence of ECVG in household stored water was associated with a significant decrease in the odds of a child within the home having diarrhea (OR = 0.51; 95% confidence interval 0.27–0.93). We also evaluated water management and hygiene behaviors. Recent hand contact with water or food was positively associated with detection of enteric pathogen markers on hands, as was relatively lower volumes of water reportedly used for daily hand washing. Enteropathogen markers in stored drinking water were more likely found among households in which the markers were also detected on hands, as well as in households with unimproved water supply and sanitation infrastructure. Conclusions The prevalence of enteric pathogen genes and the human-specific Bacteroidales fecal marker in stored water and on hands suggests extensive environmental contamination within homes both with and without reported child diarrhea. Better stored water quality among households with diarrhea indicates caregivers with sick children may be more likely to ensure safe drinking water in the home. Interventions to increase the quantity of water available for hand washing, and to improve food hygiene, may reduce exposure to enteric pathogens in the domestic environment. PMID:24392161

iHand: an interactive bare-hand-based augmented reality interface on commercial mobile phones

NASA Astrophysics Data System (ADS)

Choi, Junyeong; Park, Jungsik; Park, Hanhoon; Park, Jong-Il

2013-02-01

The performance of mobile phones has rapidly improved, and they are emerging as a powerful platform. In many vision-based applications, human hands play a key role in natural interaction. However, relatively little attention has been paid to the interaction between human hands and the mobile phone. Thus, we propose a vision- and hand gesture-based interface in which the user holds a mobile phone in one hand but sees the other hand's palm through a built-in camera. The virtual contents are faithfully rendered on the user's palm through palm pose estimation, and reaction with hand and finger movements is achieved that is recognized by hand shape recognition. Since the proposed interface is based on hand gestures familiar to humans and does not require any additional sensors or markers, the user can freely interact with virtual contents anytime and anywhere without any training. We demonstrate that the proposed interface works at over 15 fps on a commercial mobile phone with a 1.2-GHz dual core processor and 1 GB RAM.

Software and electronic developments for TUG - T60 robotic telescope

NASA Astrophysics Data System (ADS)

Parmaksizoglu, M.; Dindar, M.; Kirbiyik, H.; Helhel, S.

2014-12-01

A robotic telescope is a telescope that can make observations without hands-on human control. Its low level behavior is automatic and computer-controlled. Robotic telescopes usually run under the control of a scheduler, which provides high-level control by selecting astronomical targets for observation. TUBITAK National Observatory (TUG) T60 Robotic Telescope is controlled by open source OCAAS software, formally named TALON. This study introduces the improvements on TALON software, new electronic and mechanic designs. The designs and software improvements were implemented in the T60 telescope control software and tested on the real system successfully.

Ultra-weak photon emission as a non-invasive tool for monitoring of oxidative processes in the epidermal cells of human skin: comparative study on the dorsal and the palm side of the hand.

PubMed

Rastogi, Anshu; Pospísil, Pavel

2010-08-01

All living organisms emit spontaneous ultra-weak photon emission as a result of cellular metabolic processes. Exposure of living organisms to exogenous factors results in oxidative processes and enhancement in ultra-weak photon emission. Here, hydrogen peroxide (H(2)O(2)), as a strongly oxidizing molecule, was used to induce oxidative processes and enhance ultra-weak photon emission in human hand skin. The presented work intends to compare both spontaneous and peroxide-induced ultra-weak photon emission from the epidermal cells on the dorsal and the palm side of the hand. A highly sensitive photomultiplier tube and a charge-coupled device camera were used to detect ultra-weak photon emission from human hand skin. Spontaneous ultra-weak photon emission from the epidermal cells on the dorsal side of the hand was 4 counts/s. Topical application of 500 mM H(2)O(2) to the dorsal side of the hand caused enhancement in ultra-weak photon emission to 40 counts/s. Interestingly, both spontaneous and peroxide-induced ultra-weak photon emission from the epidermal cells on the palm side of the hand were observed to increase twice their values, i.e. 8 and 80 counts/s, respectively. Similarly, the two-dimensional image of ultra-weak photon emission observed after topical application of H(2)O(2) to human skin reveals that photon emission from the palm side exceeds the photon emission from the dorsal side of the hand. The results presented indicate that the ultra-weak photon emission originating from the epidermal cells on the dorsal and the palm side of the hand is related to the histological structure of the human hand skin. Ultra-weak photon emission is shown as a non-destructive technique for monitoring of oxidative processes in the epidermal cells of the human hand skin and as a diagnostic tool for skin diseases.

The evolution of human and ape hand proportions.

PubMed

Almécija, Sergio; Smaers, Jeroen B; Jungers, William L

2015-07-14

Human hands are distinguished from apes by possessing longer thumbs relative to fingers. However, this simple ape-human dichotomy fails to provide an adequate framework for testing competing hypotheses of human evolution and for reconstructing the morphology of the last common ancestor (LCA) of humans and chimpanzees. We inspect human and ape hand-length proportions using phylogenetically informed morphometric analyses and test alternative models of evolution along the anthropoid tree of life, including fossils like the plesiomorphic ape Proconsul heseloni and the hominins Ardipithecus ramidus and Australopithecus sediba. Our results reveal high levels of hand disparity among modern hominoids, which are explained by different evolutionary processes: autapomorphic evolution in hylobatids (extreme digital and thumb elongation), convergent adaptation between chimpanzees and orangutans (digital elongation) and comparatively little change in gorillas and hominins. The human (and australopith) high thumb-to-digits ratio required little change since the LCA, and was acquired convergently with other highly dexterous anthropoids.

The evolution of human and ape hand proportions

PubMed Central

Almécija, Sergio; Smaers, Jeroen B.; Jungers, William L.

2015-01-01

Human hands are distinguished from apes by possessing longer thumbs relative to fingers. However, this simple ape-human dichotomy fails to provide an adequate framework for testing competing hypotheses of human evolution and for reconstructing the morphology of the last common ancestor (LCA) of humans and chimpanzees. We inspect human and ape hand-length proportions using phylogenetically informed morphometric analyses and test alternative models of evolution along the anthropoid tree of life, including fossils like the plesiomorphic ape Proconsul heseloni and the hominins Ardipithecus ramidus and Australopithecus sediba. Our results reveal high levels of hand disparity among modern hominoids, which are explained by different evolutionary processes: autapomorphic evolution in hylobatids (extreme digital and thumb elongation), convergent adaptation between chimpanzees and orangutans (digital elongation) and comparatively little change in gorillas and hominins. The human (and australopith) high thumb-to-digits ratio required little change since the LCA, and was acquired convergently with other highly dexterous anthropoids. PMID:26171589

Paleoneurology: neurodegenerative diseases are age-related diseases of specific brain regions recently developed by Homo sapiens.

PubMed

Ghika, J

2008-11-01

Bipedal locomotion and fine motility of hand and larynx of humans introduced musculoskeletal adaptations, new pyramidal, corticostriatal, corticobulbar, nigrostriatal, and cerebellar pathways and expansions of prefrontal, cingular, parieto-temporal and occipital cortices with derived new brain capabilities. All selectively degenerate in aged homo sapiens following 16 syndromic presentations: (1) Parkinsonism: nigrostriatal control for fast automatic movements of hand, larynx, bipedal posture and gait ("simian gait and hand"). (2) Frontal (highest level) gait disorders (lower body parkinsonism, gait apraxia, retropulsion): prefrontostriatal executive control of bipedal locomotion. (3) ataxia: new synergistic coordination of bipedal gait and fine motility. (4) Dyskinesias (chorea, dystonia, tremor...): intrusions of simian basal ganglia motor subroutines. (5) motoneuron diseases: new proximo-distal and bulbar motoneurones, preserving older ones (oculomotor, abdominal...). (6) Archaic reflexes: prefrontal disinhibition of old mother/tree-climbing-oriented reflexes (sucking, grasping, Babinski/triple retraction, gegenhalten), group alarms (laughter, crying, yawning, grunting...) or grooming (tremor=scratching). (7) Dysautonomia: contextual regulation (orthostatism...). (8) REM sleep disorders of new cortical functions. (9) Corticobasal syndrome: melokinetic control of hand prehension-manipulation and language (retrocession to simian patterns). (10) Frontal/temporal lobe degeneration: medial-orbitofrontal behavioural variant: self monitoring of internal needs and social context: apathy, loss of personal hygiene, stereotypia, disinhibition, loss of concern for consequences of acts, social rules, danger and empathy; dorsolateral executive variant: inadequacy to the context of action (goal, environmental changes...); progressive non-fluent aphasia: executive and praxic processing of speech; temporal variant: abstract concepts for speech, gestures and vision (semantic dementia, progressive nonfluent aphasia) (11) Temporomesial-limbic-paralimbic-associative cortical dementias (Alzheimer's disease, Lewy body, progressive amnesia): processing of explicit cognition: amnesic syndrome, processing of hand, larynx and eye: disorientation, ideomotor apraxia, agnosia, visuospatial processing, transcortical aphasia. (12) Focal posterior atrophy (Benson, progressive apraxia): visuomotor processing of what and where. (13) Macular degeneration: retinal "spot" for explicit symbols. (14) "Psychiatric syndromes": metacognition, self monitoring and regulation of hierarchical processing of metacognition: hallucinations, delusions, magic and mystic logic, delusions, confabulations; drive: impulsivity, obsessive-compulsive disorders, mental automatisms; social interactions: theory of mind, autism, Asperger. (15) Mood disorders: control on emotions: anxio-depressive and bipolar disorders, moria, emotional lability. (16) Musculoskeletal: inclusion body myositis: muscles for bipedal gait and fine motility. Paget's disease: bones for bipedal gait and cranium. Understanding of the genetic mechanisms underlying the evolution of these recent human brain regions and paleoneurology my be the key to the focal, asymmetrical or systemic character of neurodegeneration, the pathologic heterogeneity/overlap of syndromic presentations associating gait, hand, language, cognition, mood and behaviour disorders.

Atypical activation of the mirror neuron system during perception of hand motion in autism.

PubMed

Martineau, Joëlle; Andersson, Frédéric; Barthélémy, Catherine; Cottier, Jean-Philippe; Destrieux, Christophe

2010-03-12

Disorders in the autism spectrum are characterized by deficits in social and communication skills such as imitation, pragmatic language, theory of mind, and empathy. The discovery of the "mirror neuron system" (MNS) in macaque monkeys may provide a basis from which to explain some of the behavioral dysfunctions seen in individuals with autism spectrum disorders (ASD).We studied seven right-handed high-functioning male autistic and eight normal subjects (TD group) using functional magnetic resonance imaging during observation and execution of hand movements compared to a control condition (rest). The between group comparison of the contrast [observation versus rest] provided evidence of a bilateral greater activation of inferior frontal gyrus during observation of human motion than during rest for the ASD group than for the TD group. This hyperactivation of the pars opercularis (belonging to the MNS) during observation of human motion in autistic subjects provides strong support for the hypothesis of atypical activity of the MNS that may be at the core of the social deficits in autism. Copyright 2010 Elsevier B.V. All rights reserved.

Teleoperation of Robonaut Using Finger Tracking

NASA Technical Reports Server (NTRS)

Champoux, Rachel G.; Luo, Victor

2012-01-01

With the advent of new finger tracking systems, the idea of a more expressive and intuitive user interface is being explored and implemented. One practical application for this new kind of interface is that of teleoperating a robot. For humanoid robots, a finger tracking interface is required due to the level of complexity in a human-like hand, where a joystick isn't accurate. Moreover, for some tasks, using one's own hands allows the user to communicate their intentions more effectively than other input. The purpose of this project was to develop a natural user interface for someone to teleoperate a robot that is elsewhere. Specifically, this was designed to control Robonaut on the international space station to do tasks too dangerous and/or too trivial for human astronauts. This interface was developed by integrating and modifying 3Gear's software, which includes a library of gestures and the ability to track hands. The end result is an interface in which the user can manipulate objects in real time in the user interface. then, the information is relayed to a simulator, the stand in for Robonaut, at a slight delay.

Finger impedance evaluation by means of hand exoskeleton.

PubMed

Fiorilla, Angelo Emanuele; Nori, Francesco; Masia, Lorenzo; Sandini, Giulio

2011-12-01

Modulation of arm mechanical impedance is a fundamental aspect for interaction with the external environment and its regulation is essential for stability preservation during manipulation. Even though past research on human arm movements has suggested that models of human finger impedance would benefit the study of neural control mechanisms and the design of novel hand prostheses, relatively few studies have focused on finger and hand impedance. This article touches on the two main aspects of this research topic: first it introduces a mechanical refinement of a device that can be used to effectively measure finger impedance during manipulation tasks; then, it describes a pilot study aimed at identifying the inertia of the finger and the viscous and elastic properties of finger muscles. The proposed wearable exoskeleton, which has been designed to measure finger posture and impedance modulation while leaving the palm free, is capable of applying fast displacements while monitoring the interaction forces between the human finger and the robotic links. Moreover, due to the relatively small inertia of the fingers, it allows us to meet some stringent specifications, performing relatively large displacements (~45°) before the stretch reflex intervenes (~25 ms). The results of measurements on five subjects show that inertia, damping, and stiffness can be effectively identified and that the parameters obtained are comparable with values from previous studies.

Force Control and Nonlinear Master-Slave Force Profile to Manage an Admittance Type Multi-Fingered Haptic User Interface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anthony L. Crawford

2012-08-01

Natural movements and force feedback are important elements in using teleoperated equipment if complex and speedy manipulation tasks are to be accomplished in remote and/or hazardous environments, such as hot cells, glove boxes, decommissioning, explosives disarmament, and space to name a few. In order to achieve this end the research presented in this paper has developed an admittance type exoskeleton like multi-fingered haptic hand user interface that secures the user’s palm and provides 3-dimensional force feedback to the user’s fingertips. Atypical to conventional haptic hand user interfaces that limit themselves to integrating the human hand’s characteristics just into the system’smore » mechanical design this system also perpetuates that inspiration into the designed user interface’s controller. This is achieved by manifesting the property differences of manipulation and grasping activities as they pertain to the human hand into a nonlinear master-slave force relationship. The results presented in this paper show that the admittance-type system has sufficient bandwidth that it appears nearly transparent to the user when the user is in free motion and when the system is subjected to a manipulation task, increased performance is achieved using the nonlinear force relationship compared to the traditional linear scaling techniques implemented in the vast majority of systems.« less

Using an Artificial Neural Bypass to Restore Cortical Control of Rhythmic Movements in a Human with Quadriplegia

NASA Astrophysics Data System (ADS)

Sharma, Gaurav; Friedenberg, David A.; Annetta, Nicholas; Glenn, Bradley; Bockbrader, Marcie; Majstorovic, Connor; Domas, Stephanie; Mysiw, W. Jerry; Rezai, Ali; Bouton, Chad

2016-09-01

Neuroprosthetic technology has been used to restore cortical control of discrete (non-rhythmic) hand movements in a paralyzed person. However, cortical control of rhythmic movements which originate in the brain but are coordinated by Central Pattern Generator (CPG) neural networks in the spinal cord has not been demonstrated previously. Here we show a demonstration of an artificial neural bypass technology that decodes cortical activity and emulates spinal cord CPG function allowing volitional rhythmic hand movement. The technology uses a combination of signals recorded from the brain, machine-learning algorithms to decode the signals, a numerical model of CPG network, and a neuromuscular electrical stimulation system to evoke rhythmic movements. Using the neural bypass, a quadriplegic participant was able to initiate, sustain, and switch between rhythmic and discrete finger movements, using his thoughts alone. These results have implications in advancing neuroprosthetic technology to restore complex movements in people living with paralysis.

Internship Abstract and Final Reflection

NASA Technical Reports Server (NTRS)

Sandor, Edward

2016-01-01

The primary objective for this internship is the evaluation of an embedded natural language processor (NLP) as a way to introduce voice control into future space suits. An embedded natural language processor would provide an astronaut hands-free control for making adjustments to the environment of the space suit and checking status of consumables procedures and navigation. Additionally, the use of an embedded NLP could potentially reduce crew fatigue, increase the crewmember's situational awareness during extravehicular activity (EVA) and improve the ability to focus on mission critical details. The use of an embedded NLP may be valuable for other human spaceflight applications desiring hands-free control as well. An embedded NLP is unique because it is a small device that performs language tasks, including speech recognition, which normally require powerful processors. The dedicated device could perform speech recognition locally with a smaller form-factor and lower power consumption than traditional methods.

Comparison of Standard Culture-Based Method to Culture-Independent Method for Evaluation of Hygiene Effects on the Hand Microbiome.

PubMed

Zapka, C; Leff, J; Henley, J; Tittl, J; De Nardo, E; Butler, M; Griggs, R; Fierer, N; Edmonds-Wilson, S

2017-03-28

Hands play a critical role in the transmission of microbiota on one's own body, between individuals, and on environmental surfaces. Effectively measuring the composition of the hand microbiome is important to hand hygiene science, which has implications for human health. Hand hygiene products are evaluated using standard culture-based methods, but standard test methods for culture-independent microbiome characterization are lacking. We sampled the hands of 50 participants using swab-based and glove-based methods prior to and following four hand hygiene treatments (using a nonantimicrobial hand wash, alcohol-based hand sanitizer [ABHS], a 70% ethanol solution, or tap water). We compared results among culture plate counts, 16S rRNA gene sequencing of DNA extracted directly from hands, and sequencing of DNA extracted from culture plates. Glove-based sampling yielded higher numbers of unique operational taxonomic units (OTUs) but had less diversity in bacterial community composition than swab-based sampling. We detected treatment-induced changes in diversity only by using swab-based samples ( P < 0.001); we were unable to detect changes with glove-based samples. Bacterial cell counts significantly decreased with use of the ABHS ( P < 0.05) and ethanol control ( P < 0.05). Skin hydration at baseline correlated with bacterial abundances, bacterial community composition, pH, and redness across subjects. The importance of the method choice was substantial. These findings are important to ensure improvement of hand hygiene industry methods and for future hand microbiome studies. On the basis of our results and previously published studies, we propose recommendations for best practices in hand microbiome research. IMPORTANCE The hand microbiome is a critical area of research for diverse fields, such as public health and forensics. The suitability of culture-independent methods for assessing effects of hygiene products on microbiota has not been demonstrated. This is the first controlled laboratory clinical hand study to have compared traditional hand hygiene test methods with newer culture-independent characterization methods typically used by skin microbiologists. This study resulted in recommendations for hand hygiene product testing, development of methods, and future hand skin microbiome research. It also demonstrated the importance of inclusion of skin physiological metadata in skin microbiome research, which is atypical for skin microbiome studies. Copyright © 2017 Zapka et al.

Within- and between-task consistency in hand use as a means of characterizing hand preferences in captive chimpanzees (Pan troglodytes).

PubMed

Hopkins, William D; Gardner, Molly; Mingle, Morgan; Reamer, Lisa; Schapiro, Steven J

2013-11-01

There remain considerable questions regarding the evidence for population-level handedness in nonhuman primates when compared with humans. One challenge in comparing human and nonhuman primate handedness involves the procedures used to characterize individual handedness. Studies of human handedness use consistency in hand use within and between tasks as a basis for hand preference classification. In contrast, studies of handedness in nonhuman primates use statistical criteria for classifying handedness. In this study, we examined within- and between-task consistency in hand use as a means of characterizing individual handedness in a sample of 300 captive chimpanzees (Pan troglodytes). Chimpanzees showed population-level right-handedness for both within- and between-tasks consistency, though the proportion of right-handed chimpanzees was lower than what has typically been reported for humans. We further found that there were small, but significant, associations in hand use between measures. There were no significant sex or colony effects on the distribution of handedness. The results are discussed in the context of theories on the evolution of handedness in nonhuman primates.

Within- and Between-Task Consistency in Hand Use as a Means of Characterizing Hand Preferences in Captive Chimpanzees (Pan troglodytes)

PubMed Central

Hopkins, William D.; Gardner, Molly; Mingle, Morgan; Reamer, Lisa; Schapiro, Steven J.

2013-01-01

There remain considerable questions regarding the evidence for population-level handedness in nonhuman primates when compared with humans. One challenge in comparing human and nonhuman primate handedness involves the procedures used to characterize individual handedness. Studies of human handedness use consistency in hand use within and between tasks as a basis for hand preference classification. In contrast, studies of handedness in nonhuman primates use statistical criteria for classifying handedness. In this study, we examined within- and between-task consistency in hand use as a means of characterizing individual handedness in a sample of 300 captive chimpanzees (Pan troglodytes). Chimpanzees showed population-level right-handedness for both within- and between-tasks consistency, though the proportion of right-handed chimpanzees was lower than what has typically been reported for humans. We further found that there were small, but significant, associations in hand use between measures. There were no significant sex or colony effects on the distribution of handedness. The results are discussed in the context of theories on the evolution of handedness in nonhuman primates. PMID:23356440

Student manual, Book 2: Orientation to occupational safety compliance in DOE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colley, D.L.

1993-10-01

This is a student hand-book an Occupational Safety Compliance in DOE. Topics include the following: Electrical; materials handling & storage; inspection responsibilities & procedures; general environmental controls; confined space entry; lockout/tagout; office safety, ergonomics & human factors; medical & first aid, access to records; construction safety; injury/illness reporting system; and accident investigation procedures.

Utilizing Glove-Based Gestures and a Tactile Vest Display for Covert Communications and Robot Control

DTIC Science & Technology

2014-06-01

transmitted from a controller mechanism that contains inertial measurement unit ( IMU ) sensors to sense rotation and acceleration of movement. Earlier...assets, and standard hand signal commands can be presented to human team members via a variety of modalities. IMU sensor technologies placed on the body...obstacle event (e.g., climbing, crawling, combat roll , running) and between obstacles (i.e., walking). The following analyses are for each task

Embodiment and Manipulation Learning Process for a Humanoid Hand.

DTIC Science & Technology

1995-05-01

Figures 1-1 Human somatotopic mappings 16 1-2 Human anatomy terminology 18 2-1 A picture of Cog 24 2-2 A picture of Cog’s hand 27 3-1 A... human anatomy terminologies shown in Figure 1-2 [24]. The mechanical hand constructed for this thesis have three fingers, each having two segments...and two joints, and a thumb with one segment and a joint, so the terms 18 CHAPTER 1. INTRODUCTION Saddle-joint of the thumb Figure 1-2: Human

Evolution of the central sulcus morphology in primates.

PubMed

Hopkins, William D; Meguerditchian, Adrien; Coulon, Olivier; Bogart, Stephanie; Mangin, Jean-François; Sherwood, Chet C; Grabowski, Mark W; Bennett, Allyson J; Pierre, Peter J; Fears, Scott; Woods, Roger; Hof, Patrick R; Vauclair, Jacques

2014-01-01

The central sulcus (CS) divides the pre- and postcentral gyri along the dorsal-ventral plane of which all motor and sensory functions are topographically organized. The motor-hand area of the precentral gyrus or KNOB has been described as the anatomical substrate of the hand in humans. Given the importance of the hand in primate evolution, here we examine the evolution of the motor-hand area by comparing the relative size and pattern of cortical folding of the CS surface area from magnetic resonance images in 131 primates, including Old World monkeys, apes and humans. We found that humans and great apes have a well-formed motor-hand area that can be seen in the variation in depth of the CS along the dorsal-ventral plane. We further found that great apes have relatively large CS surface areas compared to Old World monkeys. However, relative to great apes, humans have a small motor-hand area in terms of both adjusted and absolute surface areas. © 2014 S. Karger AG, Basel.

Reflections on the differences between religion and culture.

PubMed

Bonney, Richard

2004-01-01

Culture may be thought of as a causal agent that affects the evolutionary process by uniquely human means. Religion, on the other hand, is considered a process of revelation and contains the concept of the "faithful" who receive the message of revelation. Culture permits the "self-conscious evaluation of human possibilities" and therefore presents a device for increasing human control over species change. There are dangers, however, in accepting cultural relativism without any constraint, such as respect for human life and dignity. In this article, the author attempts to clarify the boundaries between religion and culture and acknowledges that further research is needed on the religion/culture dichotomy.

Video observation of hand hygiene practices during routine companion animal appointments and the effect of a poster intervention on hand hygiene compliance

PubMed Central

2014-01-01

Background Hand hygiene is considered one of the most important infection control measures in human healthcare settings, but there is little information available regarding hand hygiene frequency and technique used in veterinary clinics. The objectives of this study were to describe hand hygiene practices associated with routine appointments in companion animal clinics in Ontario, and the effectiveness of a poster campaign to improve hand hygiene compliance. Results Observation of hand hygiene practices was performed in 51 clinics for approximately 3 weeks each using 2 small wireless surveillance cameras: one in an exam room, and one in the most likely location for hand hygiene to be performed outside the exam room following an appointment. Data from 38 clinics were included in the final analysis, including 449 individuals, 1139 appointments before and after the poster intervention, and 10894 hand hygiene opportunities. Overall hand hygiene compliance was 14% (1473/10894), while before and after patient contact compliance was 3% (123/4377) and 26% (1145/4377), respectively. Soap and water was used for 87% (1182/1353) of observed hand hygiene attempts with a mean contact time of 4 s (median 2 s, range 1-49 s), while alcohol-based hand rub (ABHR) was used for 7% (98/1353) of attempts with a mean contact time of 8 s (median 7 s, range 1-30 s). The presence of the posters had no significant effect on compliance, although some staff reported that they felt the posters did increase their personal awareness of the need to perform hand hygiene, and the posters had some effect on product contact times. Conclusions Overall hand hygiene compliance in veterinary clinics in this study was low, and contact time with hand hygiene products was frequently below current recommendations. Use of ABHR was low despite its advantages over hand washing and availability in the majority of clinics. The poster campaign had a limited effect on its own, but could still be used as a component of a multimodal hand hygiene campaign. Improving the infection control culture in veterinary medicine would facilitate future campaigns and studies in this area, as well as overall patient and staff safety. PMID:24885304

Video observation of hand hygiene practices during routine companion animal appointments and the effect of a poster intervention on hand hygiene compliance.

PubMed

Anderson, Maureen E C; Sargeant, Jan M; Weese, J Scott

2014-05-07

Hand hygiene is considered one of the most important infection control measures in human healthcare settings, but there is little information available regarding hand hygiene frequency and technique used in veterinary clinics. The objectives of this study were to describe hand hygiene practices associated with routine appointments in companion animal clinics in Ontario, and the effectiveness of a poster campaign to improve hand hygiene compliance. Observation of hand hygiene practices was performed in 51 clinics for approximately 3 weeks each using 2 small wireless surveillance cameras: one in an exam room, and one in the most likely location for hand hygiene to be performed outside the exam room following an appointment. Data from 38 clinics were included in the final analysis, including 449 individuals, 1139 appointments before and after the poster intervention, and 10894 hand hygiene opportunities. Overall hand hygiene compliance was 14% (1473/10894), while before and after patient contact compliance was 3% (123/4377) and 26% (1145/4377), respectively. Soap and water was used for 87% (1182/1353) of observed hand hygiene attempts with a mean contact time of 4 s (median 2 s, range 1-49 s), while alcohol-based hand rub (ABHR) was used for 7% (98/1353) of attempts with a mean contact time of 8 s (median 7 s, range 1-30 s). The presence of the posters had no significant effect on compliance, although some staff reported that they felt the posters did increase their personal awareness of the need to perform hand hygiene, and the posters had some effect on product contact times. Overall hand hygiene compliance in veterinary clinics in this study was low, and contact time with hand hygiene products was frequently below current recommendations. Use of ABHR was low despite its advantages over hand washing and availability in the majority of clinics. The poster campaign had a limited effect on its own, but could still be used as a component of a multimodal hand hygiene campaign. Improving the infection control culture in veterinary medicine would facilitate future campaigns and studies in this area, as well as overall patient and staff safety.

Proximal arm kinematics affect grip force-load force coordination

PubMed Central

Vermillion, Billy C.; Lum, Peter S.

2015-01-01

During object manipulation, grip force is coordinated with load force, which is primarily determined by object kinematics. Proximal arm kinematics may affect grip force control, as proximal segment motion could affect control of distal hand muscles via biomechanical and/or neural pathways. The aim of this study was to investigate the impact of proximal kinematics on grip force modulation during object manipulation. Fifteen subjects performed three vertical lifting tasks that involved distinct proximal kinematics (elbow/shoulder), but resulted in similar end-point (hand) trajectories. While temporal coordination of grip and load forces remained similar across the tasks, proximal kinematics significantly affected the grip force-to-load force ratio (P = 0.042), intrinsic finger muscle activation (P = 0.045), and flexor-extensor ratio (P < 0.001). Biomechanical coupling between extrinsic hand muscles and the elbow joint cannot fully explain the observed changes, as task-related changes in intrinsic hand muscle activation were greater than in extrinsic hand muscles. Rather, between-task variation in grip force (highest during task 3) appears to contrast to that in shoulder joint velocity/acceleration (lowest during task 3). These results suggest that complex neural coupling between the distal and proximal upper extremity musculature may affect grip force control during movements, also indicated by task-related changes in intermuscular coherence of muscle pairs, including intrinsic finger muscles. Furthermore, examination of the fingertip force showed that the human motor system may attempt to reduce variability in task-relevant motor output (grip force-to-load force ratio), while allowing larger fluctuations in output less relevant to task goal (shear force-to-grip force ratio). PMID:26289460

Effect of visual and tactile feedback on kinematic synergies in the grasping hand.

PubMed

Patel, Vrajeshri; Burns, Martin; Vinjamuri, Ramana

2016-08-01

The human hand uses a combination of feedforward and feedback mechanisms to accomplish high degree of freedom in grasp control efficiently. In this study, we used a synergy-based control model to determine the effect of sensory feedback on kinematic synergies in the grasping hand. Ten subjects performed two types of grasps: one that included feedback (real) and one without feedback (memory-guided), at two different speeds (rapid and natural). Kinematic synergies were extracted from rapid real and rapid memory-guided grasps using principal component analysis. Synergies extracted from memory-guided grasps revealed greater preservation of natural inter-finger relationships than those found in corresponding synergies extracted from real grasps. Reconstruction of natural real and natural memory-guided grasps was used to test performance and generalizability of synergies. A temporal analysis of reconstruction patterns revealed the differing contribution of individual synergies in real grasps versus memory-guided grasps. Finally, the results showed that memory-guided synergies could not reconstruct real grasps as accurately as real synergies could reconstruct memory-guided grasps. These results demonstrate how visual and tactile feedback affects a closed-loop synergy-based motor control system.

Implementation and design of a teleoperation system based on a VMEBUS/68020 pipelined architecture

NASA Technical Reports Server (NTRS)

Lee, Thomas S.

1989-01-01

A pipelined control design and architecture for a force-feedback teleoperation system that is being implemented at the Jet Propulsion Laboratory and which will be integrated with the autonomous portion of the testbed to achieve share control is described. At the local site, the operator sees real-time force/torque displays and moves two 6-degree of freedom (dof) force-reflecting hand-controllers as his hands feel the contact force/torques generated at the remote site where the robots interact with the environment. He also uses a graphical user menu to monitor robot states and specify system options. The teleoperation software is written in the C language and runs on MC68020-based processor boards in the VME chassis, which utilizes a real-time operating system; the hardware is configured to realize a four-stage pipeline configuration. The environment is very flexible, such that the system can easily be configured as a stand-alone facility for performing independent research in human factors, force control, and time-delayed systems.

Efficacy of a new educational tool to improve Handrubbing technique amongst healthcare workers: a controlled, before-after study.

PubMed

Stewardson, Andrew J; Iten, Anne; Camus, Véronique; Gayet-Ageron, Angèle; Caulfield, Darren; Lacey, Gerard; Pittet, Didier

2014-01-01

Hand hygiene is a key component of infection control in healthcare. WHO recommends that healthcare workers perform six specific poses during each hand hygiene action. SureWash (Glanta Ltd, Dublin, Ireland) is a novel device that uses video-measurement technology and immediate feedback to teach this technique. We assessed the impact of self-directed SureWash use on healthcare worker hand hygiene technique and evaluated the device's diagnostic capacity. A controlled before-after study: subjects in Group A were exposed to the SureWash for four weeks followed by Group B for 12 weeks. Each subject's hand hygiene technique was assessed by blinded observers at baseline (T0) and following intervention periods (T1 and T2). Primary outcome was performance of a complete hand hygiene action, requiring all six poses during an action lasting ≥20 seconds. The number of poses per hand hygiene action (maximum 6) was assessed in a post-hoc analysis. SureWash's diagnostic capacity compared to human observers was assessed using ROC curve analysis. Thirty-four and 29 healthcare workers were recruited to groups A and B, respectively. No participants performed a complete action at baseline. At T1, one Group A participant and no Group B participants performed a complete action. At baseline, the median number of poses performed per action was 2.0 and 1.0 in Groups A and B, respectively (p = 0.12). At T1, the number of poses per action was greater in Group A (post-intervention) than Group B (control): median 3.8 and 2.0, respectively (p<0.001). In Group A, the number of poses performed twelve weeks post-intervention (median 3.0) remained higher than baseline (p<0.001). The area under the ROC curves for the 6 poses ranged from 0.59 to 0.88. While no impact on complete actions was demonstrated, SureWash significantly increased the number of poses per hand hygiene action and demonstrated good diagnostic capacity.

Hand-Rearing Reduces Fear of Humans in European Starlings, Sturnus vulgaris

PubMed Central

Feenders, Gesa; Bateson, Melissa

2011-01-01

Pending changes in European legislation ban the use of wild-caught animals in research. This change is partly justified on the assumption that captive-breeding (or hand-rearing) increases welfare of captive animals because these practices result in animals with reduced fear of humans. However, there are few actual data on the long-term behavioural effects of captive-breeding in non-domestic species, and these are urgently needed in order to understand the welfare and scientific consequences of adopting this practice. We compared the response of hand-reared and wild-caught starlings to the presence of a human in the laboratory. During human presence, all birds increased their general locomotor activity but the wild-caught birds moved away from the human and were less active than the hand-reared birds. After the human departed, the wild-caught birds were slower to decrease their activity back towards baseline levels, and showed a dramatic increase in time at the periphery of the cage compared with the hand-reared birds. We interpret these data as showing evidence of a greater fear response in wild-caught birds with initial withdrawal followed by a subsequent rebound of prolonged attempts to escape the cage. We found no effects of environmental enrichment. However, birds in cages on low shelves were less active than birds on upper shelves, and showed a greater increase in the time spent at the periphery of their cages after the human departed, perhaps indicating that the lower cages were more stressful. In demonstrating reduced fear of humans in hand-reared birds, our results support one of the proposed welfare benefits of this practice, but without further data on the possible welfare costs of hand-rearing, it is not yet possible to reach a general conclusion about its net welfare impact. However, our results confirm a clear scientific impact of both hand-rearing and cage position at the behavioural level. PMID:21364770

The 3D model control of image processing

NASA Technical Reports Server (NTRS)

Nguyen, An H.; Stark, Lawrence

1989-01-01

Telerobotics studies remote control of distant robots by a human operator using supervisory or direct control. Even if the robot manipulators has vision or other senses, problems arise involving control, communications, and delay. The communication delays that may be expected with telerobots working in space stations while being controlled from an Earth lab have led to a number of experiments attempting to circumvent the problem. This delay in communication is a main motivating factor in moving from well understood instantaneous hands-on manual control to less well understood supervisory control; the ultimate step would be the realization of a fully autonomous robot. The 3-D model control plays a crucial role in resolving many conflicting image processing problems that are inherent in resolving in the bottom-up approach of most current machine vision processes. The 3-D model control approach is also capable of providing the necessary visual feedback information for both the control algorithms and for the human operator.

Admittance Control for Robot Assisted Retinal Vein Micro-Cannulation under Human-Robot Collaborative Mode.

PubMed

Zhang, He; Gonenc, Berk; Iordachita, Iulian

2017-10-01

Retinal vein occlusion is one of the most common retinovascular diseases. Retinal vein cannulation is a potentially effective treatment method for this condition that currently lies, however, at the limits of human capabilities. In this work, the aim is to use robotic systems and advanced instrumentation to alleviate these challenges, and assist the procedure via a human-robot collaborative mode based on our earlier work on the Steady-Hand Eye Robot and force-sensing instruments. An admittance control method is employed to stabilize the cannula relative to the vein and maintain it inside the lumen during the injection process. A pre-stress strategy is used to prevent the tip of microneedle from getting out of vein in in prolonged infusions, and the performance is verified through simulations.

Intelligent laser soldering inspection and process control

NASA Technical Reports Server (NTRS)

Vanzetti, Riccardo

1987-01-01

Component assembly on printed circuitry keeps making giant strides toward denser packaging and smaller dimensions. From a single layer to multilayer, from through holes to surface mounted components and tape applied bonds, unrelenting progress results in new, difficult problems in assembling, soldering, inspecting and controlling the manufacturing process of the new electronics. Among the major problems are the variables introduced by human operators. The small dimensions and the tight assembly tolerances are now successfully met by machines which are faster and more precise than the human hand. The same is true for soldering. But visual inspection of the solder joints is now so severely limited by the ever shrinking area accessible to the human eye that the inspector's diagnosis cannot be trusted any longer. Solutions to correcting these problems are discussed.

A Pilot Model for the NASA Simplified Aid for EVA Rescue (SAFER) (Single-Axis Pitch Task)

NASA Astrophysics Data System (ADS)

Handley, Patrick Mark

This thesis defines, tests, and validates a descriptive pilot model for a single-axis pitch control task of the Simplified Aid for EVA Rescue (SAFER). SAFER is a small propulsive jetpack used by astronauts for self-rescue. Pilot model research supports development of improved self-rescue strategies and technologies through insights into pilot behavior.This thesis defines a multi-loop pilot model. The innermost loop controls the hand controller, the middle loop controls pitch rate, and the outer loop controls pitch angle. A human-in-the-loop simulation was conducted to gather data from a human pilot. Quantitative and qualitative metrics both indicate that the model is an acceptable fit to the human data. Fuel consumption was nearly identical; time to task completion matched very well. There is some evidence that the model responds faster to initial pitch rates than the human, artificially decreasing the model's time to task completion. This pilot model is descriptive, not predictive, of the human pilot. Insights are made into pilot behavior from this research. Symmetry implies that the human responds to positive and negative initial conditions with the same strategy. The human pilot appears indifferent to pitch angles within 0.5 deg, coasts at a constant pitch rate 1.09 deg/s, and has a reaction delay of 0.1 s.

Vibration-reducing gloves: transmissibility at the palm of the hand in three orthogonal directions.

PubMed

McDowell, Thomas W; Dong, Ren G; Welcome, Daniel E; Xu, Xueyan S; Warren, Christopher

2013-01-01

Vibration-reducing (VR) gloves are commonly used as a means to help control exposures to hand-transmitted vibrations generated by powered hand tools. The objective of this study was to characterise the vibration transmissibility spectra and frequency-weighted vibration transmissibility of VR gloves at the palm of the hand in three orthogonal directions. Seven adult males participated in the evaluation of seven glove models using a three-dimensional hand-arm vibration test system. Three levels of hand coupling force were applied in the experiment. This study found that, in general, VR gloves are most effective at reducing vibrations transmitted to the palm along the forearm direction. Gloves that are found to be superior at reducing vibrations in the forearm direction may not be more effective in the other directions when compared with other VR gloves. This casts doubts on the validity of the standardised glove screening test. Practitioner Summary: This study used human subjects to measure three-dimensional vibration transmissibility of vibration-reducing gloves at the palm and identified their vibration attenuation characteristics. This study found the gloves to be most effective at reducing vibrations along the forearm direction. These gloves did not effectively attenuate vibration along the handle axial direction.

An EMG-based robot control scheme robust to time-varying EMG signal features.

PubMed

Artemiadis, Panagiotis K; Kyriakopoulos, Kostas J

2010-05-01

Human-robot control interfaces have received increased attention during the past decades. With the introduction of robots in everyday life, especially in providing services to people with special needs (i.e., elderly, people with impairments, or people with disabilities), there is a strong necessity for simple and natural control interfaces. In this paper, electromyographic (EMG) signals from muscles of the human upper limb are used as the control interface between the user and a robot arm. EMG signals are recorded using surface EMG electrodes placed on the user's skin, making the user's upper limb free of bulky interface sensors or machinery usually found in conventional human-controlled systems. The proposed interface allows the user to control in real time an anthropomorphic robot arm in 3-D space, using upper limb motion estimates based only on EMG recordings. Moreover, the proposed interface is robust to EMG changes with respect to time, mainly caused by muscle fatigue or adjustments of contraction level. The efficiency of the method is assessed through real-time experiments, including random arm motions in the 3-D space with variable hand speed profiles.

Electroencephalogram evidence for the activation of human mirror neuron system during the observation of intransitive shadow and line drawing actions☆

PubMed Central

Zhu, Huaping; Sun, Yaoru; Wang, Fang

2013-01-01

Previous studies have demonstrated that hand shadows may activate the motor cortex associated with the mirror neuron system in human brain. However, there is no evidence of activity of the human mirror neuron system during the observation of intransitive movements by shadows and line drawings of hands. This study examined the suppression of electroencephalography mu waves (8–13 Hz) induced by observation of stimuli in 18 healthy students. Three stimuli were used: real hand actions, hand shadow actions and actions made by line drawings of hands. The results showed significant desynchronization of the mu rhythm (“mu suppression”) across the sensorimotor cortex (recorded at C3, Cz and C4), the frontal cortex (recorded at F3, Fz and F4) and the central and right posterior parietal cortex (recorded at Pz and P4) under all three conditions. Our experimental findings suggest that the observation of “impoverished hand actions”, such as intransitive movements of shadows and line drawings of hands, is able to activate widespread cortical areas related to the putative human mirror neuron system. PMID:25206595

Coordination of hand shape.

PubMed

Pesyna, Colin; Pundi, Krishna; Flanders, Martha

2011-03-09

The neural control of hand movement involves coordination of the sensory, motor, and memory systems. Recent studies have documented the motor coordinates for hand shape, but less is known about the corresponding patterns of somatosensory activity. To initiate this line of investigation, the present study characterized the sense of hand shape by evaluating the influence of differences in the amount of grasping or twisting force, and differences in forearm orientation. Human subjects were asked to use the left hand to report the perceived shape of the right hand. In the first experiment, six commonly grasped items were arranged on the table in front of the subject: bottle, doorknob, egg, notebook, carton, and pan. With eyes closed, subjects used the right hand to lightly touch, forcefully support, or imagine holding each object, while 15 joint angles were measured in each hand with a pair of wired gloves. The forces introduced by supporting or twisting did not influence the perceptual report of hand shape, but for most objects, the report was distorted in a consistent manner by differences in forearm orientation. Subjects appeared to adjust the intrinsic joint angles of the left hand, as well as the left wrist posture, so as to maintain the imagined object in its proper spatial orientation. In a second experiment, this result was largely replicated with unfamiliar objects. Thus, somatosensory and motor information appear to be coordinated in an object-based, spatial-coordinate system, sensitive to orientation relative to gravitational forces, but invariant to grasp forcefulness.

Sensor fusion and computer vision for context-aware control of a multi degree-of-freedom prosthesis

NASA Astrophysics Data System (ADS)

Markovic, Marko; Dosen, Strahinja; Popovic, Dejan; Graimann, Bernhard; Farina, Dario

2015-12-01

Objective. Myoelectric activity volitionally generated by the user is often used for controlling hand prostheses in order to replicate the synergistic actions of muscles in healthy humans during grasping. Muscle synergies in healthy humans are based on the integration of visual perception, heuristics and proprioception. Here, we demonstrate how sensor fusion that combines artificial vision and proprioceptive information with the high-level processing characteristics of biological systems can be effectively used in transradial prosthesis control. Approach. We developed a novel context- and user-aware prosthesis (CASP) controller integrating computer vision and inertial sensing with myoelectric activity in order to achieve semi-autonomous and reactive control of a prosthetic hand. The presented method semi-automatically provides simultaneous and proportional control of multiple degrees-of-freedom (DOFs), thus decreasing overall physical effort while retaining full user control. The system was compared against the major commercial state-of-the art myoelectric control system in ten able-bodied and one amputee subject. All subjects used transradial prosthesis with an active wrist to grasp objects typically associated with activities of daily living. Main results. The CASP significantly outperformed the myoelectric interface when controlling all of the prosthesis DOF. However, when tested with less complex prosthetic system (smaller number of DOF), the CASP was slower but resulted with reaching motions that contained less compensatory movements. Another important finding is that the CASP system required minimal user adaptation and training. Significance. The CASP constitutes a substantial improvement for the control of multi-DOF prostheses. The application of the CASP will have a significant impact when translated to real-life scenarious, particularly with respect to improving the usability and acceptance of highly complex systems (e.g., full prosthetic arms) by amputees.

Sensor fusion and computer vision for context-aware control of a multi degree-of-freedom prosthesis.

PubMed

Markovic, Marko; Dosen, Strahinja; Popovic, Dejan; Graimann, Bernhard; Farina, Dario

2015-12-01

Myoelectric activity volitionally generated by the user is often used for controlling hand prostheses in order to replicate the synergistic actions of muscles in healthy humans during grasping. Muscle synergies in healthy humans are based on the integration of visual perception, heuristics and proprioception. Here, we demonstrate how sensor fusion that combines artificial vision and proprioceptive information with the high-level processing characteristics of biological systems can be effectively used in transradial prosthesis control. We developed a novel context- and user-aware prosthesis (CASP) controller integrating computer vision and inertial sensing with myoelectric activity in order to achieve semi-autonomous and reactive control of a prosthetic hand. The presented method semi-automatically provides simultaneous and proportional control of multiple degrees-of-freedom (DOFs), thus decreasing overall physical effort while retaining full user control. The system was compared against the major commercial state-of-the art myoelectric control system in ten able-bodied and one amputee subject. All subjects used transradial prosthesis with an active wrist to grasp objects typically associated with activities of daily living. The CASP significantly outperformed the myoelectric interface when controlling all of the prosthesis DOF. However, when tested with less complex prosthetic system (smaller number of DOF), the CASP was slower but resulted with reaching motions that contained less compensatory movements. Another important finding is that the CASP system required minimal user adaptation and training. The CASP constitutes a substantial improvement for the control of multi-DOF prostheses. The application of the CASP will have a significant impact when translated to real-life scenarious, particularly with respect to improving the usability and acceptance of highly complex systems (e.g., full prosthetic arms) by amputees.

[Stress and information-communication technologies: from videoterminal to web].

PubMed

Tomei, G; Ciarrocca, M; De Sio, S; Suppi, A; Sinibaldi, F; Di Pastena, C; Scala, B; Corbosiero, P; De Angelis, A; Prenna, A; Tomei, F; Sancini, A

2012-07-01

The relationship between stress and new technologies has always been a vexed question. Sociologists and philosophers say technology is a double edged sword, on one hand it increases the potential of human senses, while on the other hand it forces man to adopt rhythms and conditions not natural but artificial, with consequences for his physical and mental health. Modern Cognitive Ergonomic tries to analyze to technology, interacting with mental functions, causes stress and it tries to offer the most appropriate technological solutions for human work. From our analysis it emerges that the old media have an influence on mood causing episodes of insomnia, irritability, anxiety, etc., even if in a way that cannot be completely evaluated. Contrariwise, a controlled use of the web can improve the communication and the interacting abilities in patients with psychosocial distress and low social skills. Nielsen's Heuristics are a great tool to value methods of informatical and media interfaces.

Tandem internal models execute motor learning in the cerebellum.

PubMed

Honda, Takeru; Nagao, Soichi; Hashimoto, Yuji; Ishikawa, Kinya; Yokota, Takanori; Mizusawa, Hidehiro; Ito, Masao

2018-06-25

In performing skillful movement, humans use predictions from internal models formed by repetition learning. However, the computational organization of internal models in the brain remains unknown. Here, we demonstrate that a computational architecture employing a tandem configuration of forward and inverse internal models enables efficient motor learning in the cerebellum. The model predicted learning adaptations observed in hand-reaching experiments in humans wearing a prism lens and explained the kinetic components of these behavioral adaptations. The tandem system also predicted a form of subliminal motor learning that was experimentally validated after training intentional misses of hand targets. Patients with cerebellar degeneration disease showed behavioral impairments consistent with tandemly arranged internal models. These findings validate computational tandemization of internal models in motor control and its potential uses in more complex forms of learning and cognition. Copyright © 2018 the Author(s). Published by PNAS.

Climate collective risk dilemma with feedback of real-time temperatures

NASA Astrophysics Data System (ADS)

Du, Jinming; Wu, Bin; Wang, Long

2014-09-01

Controlling global warming through collective cooperation is a non-optional threshold public goods game. Previous models assume that the disaster is a sudden event and it happens with a given probability. It is shown that high risk can pave the way for reaching the cooperative target. These models, however, neglect the temperature dynamics, which is influenced by the collective behaviours. Here, we establish a temperature dynamics, and introduce the feedback between human strategy updating and the temperature change: high temperature will discount individuals' payoffs; while sufficient public goods may decrease the ever-rising temperature. We investigate how the temperature is affected by human behaviour and vice versa. It is found that, on the one hand, the temperature can be stabilized to a relatively safe level in the long run. On the other hand, the cooperation can be promoted and be maintained at a higher level, compared with public goods game models with no such feedback.

Economic Inequality Predicts Biodiversity Loss

PubMed Central

Mikkelson, Gregory M.; Gonzalez, Andrew; Peterson, Garry D.

2007-01-01

Human activity is causing high rates of biodiversity loss. Yet, surprisingly little is known about the extent to which socioeconomic factors exacerbate or ameliorate our impacts on biological diversity. One such factor, economic inequality, has been shown to affect public health, and has been linked to environmental problems in general. We tested how strongly economic inequality is related to biodiversity loss in particular. We found that among countries, and among US states, the number of species that are threatened or declining increases substantially with the Gini ratio of income inequality. At both levels of analysis, the connection between income inequality and biodiversity loss persists after controlling for biophysical conditions, human population size, and per capita GDP or income. Future research should explore potential mechanisms behind this equality-biodiversity relationship. Our results suggest that economic reforms would go hand in hand with, if not serving as a prerequisite for, effective conservation. PMID:17505535

Economic inequality predicts biodiversity loss.

PubMed

Mikkelson, Gregory M; Gonzalez, Andrew; Peterson, Garry D

2007-05-16

Human activity is causing high rates of biodiversity loss. Yet, surprisingly little is known about the extent to which socioeconomic factors exacerbate or ameliorate our impacts on biological diversity. One such factor, economic inequality, has been shown to affect public health, and has been linked to environmental problems in general. We tested how strongly economic inequality is related to biodiversity loss in particular. We found that among countries, and among US states, the number of species that are threatened or declining increases substantially with the Gini ratio of income inequality. At both levels of analysis, the connection between income inequality and biodiversity loss persists after controlling for biophysical conditions, human population size, and per capita GDP or income. Future research should explore potential mechanisms behind this equality-biodiversity relationship. Our results suggest that economic reforms would go hand in hand with, if not serving as a prerequisite for, effective conservation.

[Cellular and intracellular transport of vitamin C. The physiologic aspects].

PubMed

Szarka, András; Lőrincz, Tamás

2013-10-20

Vitamin C requirement is satisfied by natural sources and vitamin C supplements in the ordinary human diet. The two major forms of vitamin C in the diet are L-ascorbic acid and L-dehydroascorbic acid. Both ascorbate and dehydroascorbate are absorbed along the entire length of the human intestine. The reduced form, L-ascorbic acid is imported by an active mechanism, requiring two sodium-dependent vitamin C transporters (SVCT1 and SVCT2). The transport of the oxidized form, dehydroascorbate is mediated by glucose transporters GLUT1, GLUT3 and possibly GLUT4. Initial rate of uptake of both ascorbate and dehydroascorbate is saturable with increasing external substrate concentration. Vitamin C plasma concentrations are tightly controlled when the vitamin is taken orally. It has two simple reasons, on the one hand, the capacity of the transporters is limited, on the other hand the two Na+-dependent transporters can be down-regulated by an elevated level of ascorbate.

Training industrial robots with gesture recognition techniques

NASA Astrophysics Data System (ADS)

Piane, Jennifer; Raicu, Daniela; Furst, Jacob

2013-01-01

In this paper we propose to use gesture recognition approaches to track a human hand in 3D space and, without the use of special clothing or markers, be able to accurately generate code for training an industrial robot to perform the same motion. The proposed hand tracking component includes three methods: a color-thresholding model, naïve Bayes analysis and Support Vector Machine (SVM) to detect the human hand. Next, it performs stereo matching on the region where the hand was detected to find relative 3D coordinates. The list of coordinates returned is expectedly noisy due to the way the human hand can alter its apparent shape while moving, the inconsistencies in human motion and detection failures in the cluttered environment. Therefore, the system analyzes the list of coordinates to determine a path for the robot to move, by smoothing the data to reduce noise and looking for significant points used to determine the path the robot will ultimately take. The proposed system was applied to pairs of videos recording the motion of a human hand in a „real‟ environment to move the end-affector of a SCARA robot along the same path as the hand of the person in the video. The correctness of the robot motion was determined by observers indicating that motion of the robot appeared to match the motion of the video.

Robonaut 2 (R2) Overview

NASA Technical Reports Server (NTRS)

Diftler, Myron

2010-01-01

This slide presentation reviews the development and uses of the second robot designed to work in space. The presentation reviews the motivation for developing Robonaut, the cooperative commercial relationship with General Motors, the evolution design of Robonaut Robonaut 2 improvements over the first robonaut (R1), Robonaut 2's hand dexterity, finger impedance control, tactile system, finger haptics, arm control, strength, neck movement and head sensors, human interaction, and the controller. Also the plans for use on board the International Space Station are reviewed. The patent for the Phalange Tactile Load Cell is included.

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

NASA Astrophysics Data System (ADS)

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.

Durable Tactile Glove for Human or Robot Hand

NASA Technical Reports Server (NTRS)

Butzer, Melissa; Diftler, Myron A.; Huber, Eric

2010-01-01

A glove containing force sensors has been built as a prototype of tactile sensor arrays to be worn on human hands and anthropomorphic robot hands. The force sensors of this glove are mounted inside, in protective pockets; as a result of this and other design features, the present glove is more durable than earlier models.

The Whole-Hand Point: The Structure and Function of Pointing From a Comparative Perspective

PubMed Central

Leavens, David A.; Hopkins, William D.

2007-01-01

Pointing by monkeys, apes, and human infants is reviewed and compared. Pointing with the index finger is a species-typical human gesture, although human infants exhibit more whole-hand pointing than is commonly appreciated. Captive monkeys and feral apes have been reported to only rarely “spontaneously” point, although apes in captivity frequently acquire pointing, both with the index finger and with the whole hand, without explicit training. Captive apes exhibit relatively more gaze alternation while pointing than do human infants about 1 year old. Human infants are relatively more vocal while pointing than are captive apes, consistent with paralinguistic use of pointing. PMID:10608565

Brief Communication: Latent toxoplasmosis and salivary testosterone concentration--important confounding factors in second to fourth digit ratio studies.

PubMed

Flegr, Jaroslav; Lindová, Jitka; Pivoñková, Vera; Havlícek, Jan

2008-12-01

A sexually dimorphic characteristic, the second to fourth digit ratio (2D:4D ratio), has been shown to reflect the prenatal concentration of sex steroid hormones and to correlate with many personality, physiological, and life history traits. The correlations are usually stronger for the right than the left hand. Most studies have shown that the 2D:4D ratio does not vary with age or postnatal concentration of sex steroid hormones. Recently, a strong association between left hand 2D:4D ratio and infection with a common human parasite Toxoplasma has been reported. We hypothesized that the confounding effect of Toxoplasma infection on left hand 2D:4D ratio could be responsible for the stronger association between different traits and right hand rather than left hand 2D:4D ratio. This confounding effect of toxoplasmosis could also be responsible for the difficulty in finding an association between 2D:4D ratio and age or postnatal steroid hormone concentration. To test this hypothesis, we analyzed the association between sex and age and 2D:4D ratio in a population of 194 female and 106 male students with and without controlling for the confounding variables of Toxoplasma infection and testosterone concentration. Our results showed that the relationship between age and sex and 2D:4D ratio increased sharply when Toxoplasma infection and testosterone concentration were controlled. These results suggest that left hand 2D:4D ratio is more susceptible to postnatal influences and that the confounding factors of Toxoplasma infection, testosterone concentration and possibly also age, should be controlled in future 2D:4D ratio studies. Because of a stronger 2D:4D dimorphism in Toxoplasma-infected than Toxoplasma-free subjects, we predict that 2D:4D ratio dimorphism as well as right hand/left hand 2D:4D ratio dimorphism will be higher in countries with a high prevalence of Toxoplasma infection than in those with a low prevalence. (c) 2008 Wiley-Liss, Inc.

Control of an electrical prosthesis with an SSVEP-based BCI.

PubMed

Müller-Putz, Gernot R; Pfurtscheller, Gert

2008-01-01

Brain-computer interfaces (BCIs) are systems that establish a direct connection between the human brain and a computer, thus providing an additional communication channel. They are used in a broad field of applications nowadays. One important issue is the control of neuroprosthetic devices for the restoration of the grasp function in spinal-cord-injured people. In this communication, an asynchronous (self-paced) four-class BCI based on steady-state visual evoked potentials (SSVEPs) was used to control a two-axes electrical hand prosthesis. During training, four healthy participants reached an online classification accuracy between 44% and 88%. Controlling the prosthetic hand asynchronously, the participants reached a performance of 75.5 to 217.5 s to copy a series of movements, whereas the fastest possible duration determined by the setup was 64 s. The number of false negative (FN) decisions varied from 0 to 10 (the maximal possible decisions were 34). It can be stated that the SSVEP-based BCI, operating in an asynchronous mode, is feasible for the control of neuroprosthetic devices with the flickering lights mounted on its surface.

How do you get the Rose Bengal Test at the point-of-care to diagnose brucellosis in Africa? The importance of a systems approach.

PubMed

Ducrotoy, Marie J; Bardosh, Kevin L

2017-01-01

Brucellosis is a major neglected zoonotic disease, whose burden both in animals and humans is severely under-reported. Diagnosis in humans identifies cases in order to treat the disease at the individual level. In animals diagnosis is implemented at the population level in the context of appropriate control or eradication strategies. Molecular and bacteriological diagnosis are rarely undertaken in sub-Saharan Africa, at least outside research projects, due to cost, skills and laboratory infrastructure issues. The brucellosis toolbox contains a wide range of serological tests, but the perfect test for use in animals and humans respectively does not exist. Drug and diagnostic discovery for the neglected zoonoses are notoriously poor, and there is limited investment interest in developing new tools for brucellosis diagnosis. But are current tools being used to their full capacity? The rose Bengal test (RBT) stands out as an efficient, practical and very cheap test adapted for use in the resource-poor context. In this paper, we argue that a social science or system's approach to explore the practicality of improving diagnostic capacity at the point-of care in high-risk brucellosis areas of rural Africa may be a step towards solving the issue of under-diagnosis, but this must go hand-in-hand with implementation of control measures at source in the animal reservoir and capacity to treat human cases. Copyright © 2016 Elsevier B.V. All rights reserved.

Quadcopter control using a BCI

NASA Astrophysics Data System (ADS)

Rosca, S.; Leba, M.; Ionica, A.; Gamulescu, O.

2018-01-01

The paper presents how there can be interconnected two ubiquitous elements nowadays. On one hand, the drones, which are increasingly present and integrated into more and more fields of activity, beyond the military applications they come from, moving towards entertainment, real-estate, delivery and so on. On the other hand, unconventional man-machine interfaces, which are generous topics to explore now and in the future. Of these, we chose brain computer interface (BCI), which allows human-machine interaction without requiring any moving elements. The research consists of mathematical modeling and numerical simulation of a drone and a BCI. Then there is presented an application using a Parrot mini-drone and an Emotiv Insight BCI.

Body painting to promote self-active learning of hand anatomy for preclinical medical students.

PubMed

Jariyapong, Pitchanee; Punsawad, Chuchard; Bunratsami, Suchirat; Kongthong, Paranyu

2016-01-01

The purpose of this study was to use the body painting method to teach hand anatomy to a group of preclinical medical students. Students reviewed hand anatomy using the traditional method and body painting exercise. Feedback and retention of the anatomy-related information were examined by a questionnaire and multiple-choice questions, respectively, immediately and 1 month after the painting exercise. Students agreed that the exercise was advantageous and helped facilitate self-active learning after in-class anatomy lessons. While there was no significant difference in knowledge retention between the control and experimental groups, the students appreciated the exercise in which they applied body paint to the human body to learn anatomy. The body painting was an efficient tool for aiding the interactive learning of medical students and increasing the understanding of gross anatomy.

Perseveration Found in a Human Drawing Task: Six-Fingered Hands Drawn by Patients with Right Anterior Insula and Operculum Damage

PubMed Central

Niki, Chiharu; Maruyama, Takashi; Muragaki, Yoshihiro; Kumada, Takatsune

2014-01-01

Background. Perseveration has been observed in a number of behavioural contexts, including speaking, writing, and drawing. However, no previous report describes patients who show perseveration only for drawing a human figure. Objective. The present report describes a group of patients who show body awareness-related cognitive impairment during a human figure drawing task, a different presentation from previously described neuropsychological cases. Methods. Participants were 15 patients who had a frontal lobe brain tumour around the insula cortex of the right hemisphere and had subsequently undergone a neurosurgical resective operation. Participants were asked to draw a human figure in both “hands-down” and “hands-up” configurations. Results. Eight of the 15 patients drew a human figure with six fingers during the “hands-up” and the “hands-down” human figure drawing tasks (one patient drew eight fingers). A statistical analysis of potential lesion areas revealed damage to the right anterior frontal insula and operculum in this group of patients relative to the five-finger drawing group. Conclusions. Our findings reveal a newly described neuropsychological phenomenon that could reflect impairment in attention directed towards body representations. PMID:24876665

Evidence for sparse synergies in grasping actions.

PubMed

Prevete, Roberto; Donnarumma, Francesco; d'Avella, Andrea; Pezzulo, Giovanni

2018-01-12

Converging evidence shows that hand-actions are controlled at the level of synergies and not single muscles. One intriguing aspect of synergy-based action-representation is that it may be intrinsically sparse and the same synergies can be shared across several distinct types of hand-actions. Here, adopting a normative angle, we consider three hypotheses for hand-action optimal-control: sparse-combination hypothesis (SC) - sparsity in the mapping between synergies and actions - i.e., actions implemented using a sparse combination of synergies; sparse-elements hypothesis (SE) - sparsity in synergy representation - i.e., the mapping between degrees-of-freedom (DoF) and synergies is sparse; double-sparsity hypothesis (DS) - a novel view combining both SC and SE - i.e., both the mapping between DoF and synergies and between synergies and actions are sparse, each action implementing a sparse combination of synergies (as in SC), each using a limited set of DoFs (as in SE). We evaluate these hypotheses using hand kinematic data from six human subjects performing nine different types of reach-to-grasp actions. Our results support DS, suggesting that the best action representation is based on a relatively large set of synergies, each involving a reduced number of degrees-of-freedom, and that distinct sets of synergies may be involved in distinct tasks.

Design considerations to improve cognitive ergonomic issues of unmanned vehicle interfaces utilizing video game controllers.

PubMed

Oppold, P; Rupp, M; Mouloua, M; Hancock, P A; Martin, J

2012-01-01

Unmanned (UAVs, UCAVs, and UGVs) systems still have major human factors and ergonomic challenges related to the effective design of their control interface systems, crucial to their efficient operation, maintenance, and safety. Unmanned system interfaces with a human centered approach promote intuitive interfaces that are easier to learn, and reduce human errors and other cognitive ergonomic issues with interface design. Automation has shifted workload from physical to cognitive, thus control interfaces for unmanned systems need to reduce mental workload on the operators and facilitate the interaction between vehicle and operator. Two-handed video game controllers provide wide usability within the overall population, prior exposure for new operators, and a variety of interface complexity levels to match the complexity level of the task and reduce cognitive load. This paper categorizes and provides taxonomy for 121 haptic interfaces from the entertainment industry that can be utilized as control interfaces for unmanned systems. Five categories of controllers were based on the complexity of the buttons, control pads, joysticks, and switches on the controller. This allows the selection of the level of complexity needed for a specific task without creating an entirely new design or utilizing an overly complex design.

Outbreak of human metapneumovirus infection in psychiatric inpatients: implications for directly observed use of alcohol hand rub in prevention of nosocomial outbreaks.

PubMed

Cheng, V C C; Wu, A K L; Cheung, C H Y; Lau, S K P; Woo, P C Y; Chan, K H; Li, K S M; Ip, I K S; Dunn, E L W; Lee, R A; Yam, L Y C; Yuen, K Y

2007-12-01

Nosocomial outbreaks of infectious diseases in psychiatric facilities are not uncommon but the implementation of infection control measures is often difficult. Here, we report an outbreak of an acute respiratory illness in a psychiatric ward between 29 July and 20 August 2005 involving 31 patients. Human metapneumovirus was detected in seven (23%) patients by reverse transcription-polymerase chain reaction and nucleotide sequencing. A review of outbreak surveillance records showed that six nosocomial outbreaks occurred in the year 2005, of which four (67%) were confirmed or presumably related to a respiratory viral infection. Directly observed deliveries of alcohol hand rub 4-hourly during daytime to all psychiatric patients was instituted in December 2005. Only one nosocomial respiratory viral outbreak occurred in the following year. The total number of patients and staff involved in nosocomial outbreaks due to presumed or proven respiratory virus infections decreased significantly from 60 to six (P<0.001), whereas those due to all types of nosocomial outbreaks also decreased from 70 to 24 (P=0.004). Alcohol hand rub has been shown to have potent bactericidal and virucidal activity against a wide range of nosocomial pathogens. Regular use of directly observed alcohol hand rub may decrease the incidence and scale of nosocomial outbreaks due to enveloped respiratory viruses especially in mentally incapacitated patients.

Use of smartphones and portable media devices for quantifying human movement characteristics of gait, tendon reflex response, and Parkinson's disease hand tremor.

PubMed

LeMoyne, Robert; Mastroianni, Timothy

2015-01-01

Smartphones and portable media devices are both equipped with sensor components, such as accelerometers. A software application enables these devices to function as a robust wireless accelerometer platform. The recorded accelerometer waveform can be transmitted wireless as an e-mail attachment through connectivity to the Internet. The implication of such devices as a wireless accelerometer platform is the experimental and post-processing locations can be placed anywhere in the world. Gait was quantified by mounting a smartphone or portable media device proximal to the lateral malleolus of the ankle joint. Attributes of the gait cycle were quantified with a considerable accuracy and reliability. The patellar tendon reflex response was quantified by using the device in tandem with a potential energy impact pendulum to evoke the patellar tendon reflex. The acceleration waveform maximum acceleration feature of the reflex response displayed considerable accuracy and reliability. By mounting the smartphone or portable media device to the dorsum of the hand through a glove, Parkinson's disease hand tremor was quantified and contrasted with significance to a non-Parkinson's disease steady hand control. With the methods advocated in this chapter, any aspect of human movement may be quantified through smartphones or portable media devices and post-processed anywhere in the world. These wearable devices are anticipated to substantially impact the biomedical and healthcare industry.

Prosthetic finger phalanges with lifelike skin compliance for low-force social touching interactions

PubMed Central

2011-01-01

Background Prosthetic arms and hands that can be controlled by the user's electromyography (EMG) signals are emerging. Eventually, these advanced prosthetic devices will be expected to touch and be touched by other people. As realistic as they may look, the currently available prosthetic hands have physical properties that are still far from the characteristics of human skins because they are much stiffer. In this paper, different configurations of synthetic finger phalanges have been investigated for their skin compliance behaviour and have been compared with the phalanges of the human fingers and a phalanx from a commercially available prosthetic hand. Methods Handshake tests were performed to identify which areas on the human hand experience high contact forces. After these areas were determined, experiments were done on selected areas using an indenting probe to obtain the force-displacement curves. Finite element simulations were used to compare the force-displacement results of the synthetic finger phalanx designs with that of the experimental results from the human and prosthetic finger phalanges. The simulation models were used to investigate the effects of (a) varying the internal topology of the finger phalanx and (b) varying different materials for the internal and external layers. Results and Conclusions During handshake, the high magnitudes of contact forces were observed at the areas where the full grasping enclosure of the other person's hand can be achieved. From these areas, the middle phalanges of the (a) little, (b) ring, and (c) middle fingers were selected. The indentation experiments on these areas showed that a 2 N force corresponds to skin tissue displacements of more than 2 mm. The results from the simulation model show that introducing an open pocket with 2 mm height on the internal structure of synthetic finger phalanges increased the skin compliance of the silicone material to 235% and the polyurethane material to 436%, as compared to a configuration with a solid internal geometry. In addition, the study shows that an indentation of 2 N force on the synthetic skin with an open pocket can also achieve a displacement of more than 2 mm, while the finger phalanx from a commercially available prosthetic hand can only achieve 0.2 mm. PMID:21447188

Cytomegalovirus survival and transferability and the effectiveness of common hand-washing agents against cytomegalovirus on live human hands.

PubMed

Stowell, Jennifer D; Forlin-Passoni, Daniela; Radford, Kay; Bate, Sheri L; Dollard, Sheila C; Bialek, Stephanie R; Cannon, Michael J; Schmid, D Scott

2014-01-01

Congenital cytomegalovirus (CMV) transmission can occur when women acquire CMV while pregnant. Infection control guidelines may reduce risk for transmission. We studied the duration of CMV survival after application of bacteria to the hands and after transfer from the hands to surfaces and the effectiveness of cleansing with water, regular and antibacterial soaps, sanitizer, and diaper wipes. Experiments used CMV AD169 in saliva at initial titers of 1 × 10(5) infectious particles/ml. Samples from hands or surfaces (points between 0 and 15 min) were placed in culture and observed for at least 2 weeks. Samples were also tested using CMV real-time PCR. After application of bacteria to the hands, viable CMV was recovered from 17/20 swabs at 0 min, 18/20 swabs at 1 min, 5/20 swabs at 5 min, and 4/20 swabs at 15 min. After transfer, duration of survival was at least 15 min on plastic (1/2 swabs), 5 min on crackers and glass (3/4 swabs), and 1 min or less on metal and cloth (3/4 swabs); no viable virus was collected from wood, rubber, or hands. After cleansing, no viable virus was recovered using water (0/22), plain soap (0/20), antibacterial soap (0/20), or sanitizer (0/22). Viable CMV was recovered from 4/20 hands 10 min after diaper wipe cleansing. CMV remains viable on hands for sufficient times to allow transmission. CMV may be transferred to surfaces with reduced viability. Hand-cleansing methods were effective at eliminating viable CMV from hands.

Cytomegalovirus Survival and Transferability and the Effectiveness of Common Hand-Washing Agents against Cytomegalovirus on Live Human Hands

PubMed Central

Stowell, Jennifer D.; Forlin-Passoni, Daniela; Radford, Kay; Bate, Sheri L.; Dollard, Sheila C.; Bialek, Stephanie R.; Cannon, Michael J.

2014-01-01

Congenital cytomegalovirus (CMV) transmission can occur when women acquire CMV while pregnant. Infection control guidelines may reduce risk for transmission. We studied the duration of CMV survival after application of bacteria to the hands and after transfer from the hands to surfaces and the effectiveness of cleansing with water, regular and antibacterial soaps, sanitizer, and diaper wipes. Experiments used CMV AD169 in saliva at initial titers of 1 × 105 infectious particles/ml. Samples from hands or surfaces (points between 0 and 15 min) were placed in culture and observed for at least 2 weeks. Samples were also tested using CMV real-time PCR. After application of bacteria to the hands, viable CMV was recovered from 17/20 swabs at 0 min, 18/20 swabs at 1 min, 5/20 swabs at 5 min, and 4/20 swabs at 15 min. After transfer, duration of survival was at least 15 min on plastic (1/2 swabs), 5 min on crackers and glass (3/4 swabs), and 1 min or less on metal and cloth (3/4 swabs); no viable virus was collected from wood, rubber, or hands. After cleansing, no viable virus was recovered using water (0/22), plain soap (0/20), antibacterial soap (0/20), or sanitizer (0/22). Viable CMV was recovered from 4/20 hands 10 min after diaper wipe cleansing. CMV remains viable on hands for sufficient times to allow transmission. CMV may be transferred to surfaces with reduced viability. Hand-cleansing methods were effective at eliminating viable CMV from hands. PMID:24185855

Sight restoration after congenital blindness does not reinstate alpha oscillatory activity in humans

PubMed Central

Bottari, Davide; Troje, Nikolaus F.; Ley, Pia; Hense, Marlene; Kekunnaya, Ramesh; Röder, Brigitte

2016-01-01

Functional brain development is characterized by sensitive periods during which experience must be available to allow for the full development of neural circuits and associated behavior. Yet, only few neural markers of sensitive period plasticity in humans are known. Here we employed electroencephalographic recordings in a unique sample of twelve humans who had been blind from birth and regained sight through cataract surgery between four months and 16 years of age. Two additional control groups were tested: a group of visually impaired individuals without a history of total congenital blindness and a group of typically sighted individuals. The EEG was recorded while participants performed a visual discrimination task involving intact and scrambled biological motion stimuli. Posterior alpha and theta oscillations were evaluated. The three groups showed indistinguishable behavioral performance and in all groups evoked theta activity varied with biological motion processing. By contrast, alpha oscillatory activity was significantly reduced only in individuals with a history of congenital cataracts. These data document on the one hand brain mechanisms of functional recovery (related to theta oscillations) and on the other hand, for the first time, a sensitive period for the development of alpha oscillatory activity in humans. PMID:27080158

Human Flesh Search Engine and Online Privacy.

PubMed

Zhang, Yang; Gao, Hong

2016-04-01

Human flesh search engine can be a double-edged sword, bringing convenience on the one hand and leading to infringement of personal privacy on the other hand. This paper discusses the ethical problems brought about by the human flesh search engine, as well as possible solutions.

Comparison of Standard Culture-Based Method to Culture-Independent Method for Evaluation of Hygiene Effects on the Hand Microbiome

PubMed Central

Leff, J.; Henley, J.; Tittl, J.; De Nardo, E.; Butler, M.; Griggs, R.; Fierer, N.

2017-01-01

ABSTRACT Hands play a critical role in the transmission of microbiota on one’s own body, between individuals, and on environmental surfaces. Effectively measuring the composition of the hand microbiome is important to hand hygiene science, which has implications for human health. Hand hygiene products are evaluated using standard culture-based methods, but standard test methods for culture-independent microbiome characterization are lacking. We sampled the hands of 50 participants using swab-based and glove-based methods prior to and following four hand hygiene treatments (using a nonantimicrobial hand wash, alcohol-based hand sanitizer [ABHS], a 70% ethanol solution, or tap water). We compared results among culture plate counts, 16S rRNA gene sequencing of DNA extracted directly from hands, and sequencing of DNA extracted from culture plates. Glove-based sampling yielded higher numbers of unique operational taxonomic units (OTUs) but had less diversity in bacterial community composition than swab-based sampling. We detected treatment-induced changes in diversity only by using swab-based samples (P < 0.001); we were unable to detect changes with glove-based samples. Bacterial cell counts significantly decreased with use of the ABHS (P < 0.05) and ethanol control (P < 0.05). Skin hydration at baseline correlated with bacterial abundances, bacterial community composition, pH, and redness across subjects. The importance of the method choice was substantial. These findings are important to ensure improvement of hand hygiene industry methods and for future hand microbiome studies. On the basis of our results and previously published studies, we propose recommendations for best practices in hand microbiome research. PMID:28351915

Prehensile control of a hand prosthesis by a microcontroller.

PubMed

Chappell, P H; Kyberd, P J

1991-09-01

The functional replacement of a natural hand and wrist is usually achieved by a split hook or an electrically powered and myoelectrically controlled artificial hand with one degree of freedom. In contrast to the commercial devices, this paper describes an experimental hand with four electric motors, nineteen sensors, and control algorithms which are written for a microcontroller. The hand significantly improves the prehension capabilities of an artificial device and leads to a design which is easily controlled by a user as it mimics the control system of the natural hand.

Hand controller commonality evaluation process

NASA Technical Reports Server (NTRS)

Stuart, Mark A.; Bierschwale, John M.; Wilmington, Robert P.; Adam, Susan C.; Diaz, Manuel F.; Jensen, Dean G.

1990-01-01

A hand controller evaluation process has been developed to determine the appropriate hand controller configurations for supporting remotely controlled devices. These devices include remote manipulator systems (RMS), dexterous robots, and remotely-piloted free flyers. Standard interfaces were developed to evaluate six different hand controllers in three test facilities including dynamic computer simulations, kinematic computer simulations, and physical simulations. The hand controllers under consideration were six degree-of-freedom (DOF) position and rate minimaster and joystick controllers, and three-DOF rate controllers. Task performance data, subjective comments, and anthropometric data obtained during tests were used for controller configuration recommendations to the SSF Program.

Extrinsic finger and thumb muscles command a virtual hand to allow individual finger and grasp control.

PubMed

Birdwell, J Alexander; Hargrove, Levi J; Weir, Richard F ff; Kuiken, Todd A

2015-01-01

Fine-wire intramuscular electrodes were used to obtain electromyogram (EMG) signals from six extrinsic hand muscles associated with the thumb, index, and middle fingers. Subjects' EMG activity was used to control a virtual three-degree-of-freedom (DOF) hand as they conformed the hand to a sequence of hand postures testing two controllers: direct EMG control and pattern recognition control. Subjects tested two conditions using each controller: starting the hand from a predefined neutral posture before each new posture and starting the hand from the previous posture in the sequence. Subjects demonstrated their abilities to simultaneously, yet individually, move all three DOFs during the direct EMG control trials; however, results showed subjects did not often utilize this feature. Performance metrics such as failure rate and completion time showed no significant difference between the two controllers.

Kinematics of the six-degree-of-freedom force-reflecting Kraft Master

NASA Technical Reports Server (NTRS)

Williams, Robert L., II

1991-01-01

Presented here are kinematic equations for a six degree of freedom force-reflecting hand controller. The forward kinematics solution is developed and shown in simplified form. The Jacobian matrix, which uses terms from the forward kinematics solution, is derived. Both of these kinematic solutions require joint angle inputs. A calibration method is presented to determine the hand controller joint angles given the respective potentiometer readings. The kinematic relationship describing the mechanical coupling between the hand and controller shoulder and elbow joints is given. These kinematic equations may be used in an algorithm to control the hand controller as a telerobotic system component. The purpose of the hand controller is two-fold: operator commands to the telerobotic system are entered using the hand controller, and contact forces and moments from the task are reflected to the operator via the hand controller.

Performance improvement in remote manipulation with time delay by means of a learning system.

NASA Technical Reports Server (NTRS)

Freedy, A.; Weltman, G.

1973-01-01

A teleoperating system is presented that involves shared control between a human operator and a general-purpose computer-based learning machine. This setup features a trainable control network termed the autonomous control subsystem (ACS) which is able to observe the operator's control actions, learn the task at hand, and take appropriate control actions. A working ACS system is described that has been put in operation for the purpose of exploring the uses of a remote intelligence of this type. The expansion of the present system into a multifunctional learning machine capable of a greater degree of autonomy is also discussed.

Strategic measures for the control of surging antimicrobial resistance in Hong Kong and mainland of China.

PubMed

Cheng, Vincent C C; Wong, Sally C Y; Ho, Pak-Leung; Yuen, Kwok-Yung

2015-02-01

Antimicrobial-resistant bacteria are either highly prevalent or increasing rapidly in Hong Kong and China. Treatment options for these bacteria are generally limited, less effective and more expensive. The emergence and dynamics of antimicrobial resistance genes in bacteria circulating between animals, the environment and humans are not entirely known. Nonetheless, selective pressure by antibiotics on the microbiomes of animal and human, and their associated environments (especially farms and healthcare institutions), sewage systems and soil are likely to confer survival advantages upon bacteria with antimicrobial-resistance genes, which may be further disseminated through plasmids or transposons with integrons. Therefore, antibiotic use must be tightly regulated to eliminate such selective pressure, including the illegalization of antibiotics as growth promoters in animal feed and regulation of antibiotic use in veterinary practice and human medicine. Heightened awareness of infection control measures to reduce the risk of acquiring resistant bacteria is essential, especially during antimicrobial use or institutionalization in healthcare facilities. The transmission cycle must be interrupted by proper hand hygiene, environmental cleaning, avoidance of undercooked or raw food and compliance with infection control measures by healthcare workers, visitors and patients, especially during treatment with antibiotics. In addition to these routine measures, proactive microbiological screening of hospitalized patients with risk factors for carrying resistant bacteria, including history of travel to endemic countries, transfer from other hospitals, and prolonged hospitalization; directly observed hand hygiene before oral intake of drugs, food and drinks; and targeted disinfection of high-touch or mutual-touch items, such as bed rails and bed curtains, are important. Transparency of surveillance data from each institute for public scrutiny provides an incentive for controlling antimicrobial resistance in healthcare settings at an administrative level.

Strategic measures for the control of surging antimicrobial resistance in Hong Kong and mainland of China

PubMed Central

Cheng, Vincent CC; Wong, Sally CY; Ho, Pak-Leung; Yuen, Kwok-Yung

2015-01-01

Antimicrobial-resistant bacteria are either highly prevalent or increasing rapidly in Hong Kong and China. Treatment options for these bacteria are generally limited, less effective and more expensive. The emergence and dynamics of antimicrobial resistance genes in bacteria circulating between animals, the environment and humans are not entirely known. Nonetheless, selective pressure by antibiotics on the microbiomes of animal and human, and their associated environments (especially farms and healthcare institutions), sewage systems and soil are likely to confer survival advantages upon bacteria with antimicrobial-resistance genes, which may be further disseminated through plasmids or transposons with integrons. Therefore, antibiotic use must be tightly regulated to eliminate such selective pressure, including the illegalization of antibiotics as growth promoters in animal feed and regulation of antibiotic use in veterinary practice and human medicine. Heightened awareness of infection control measures to reduce the risk of acquiring resistant bacteria is essential, especially during antimicrobial use or institutionalization in healthcare facilities. The transmission cycle must be interrupted by proper hand hygiene, environmental cleaning, avoidance of undercooked or raw food and compliance with infection control measures by healthcare workers, visitors and patients, especially during treatment with antibiotics. In addition to these routine measures, proactive microbiological screening of hospitalized patients with risk factors for carrying resistant bacteria, including history of travel to endemic countries, transfer from other hospitals, and prolonged hospitalization; directly observed hand hygiene before oral intake of drugs, food and drinks; and targeted disinfection of high-touch or mutual-touch items, such as bed rails and bed curtains, are important. Transparency of surveillance data from each institute for public scrutiny provides an incentive for controlling antimicrobial resistance in healthcare settings at an administrative level. PMID:26038766

Disruption of State Estimation in the Human Lateral Cerebellum

PubMed Central

Miall, R. Chris; Christensen, Lars O. D; Cain, Owen; Stanley, James

2007-01-01

The cerebellum has been proposed to be a crucial component in the state estimation process that combines information from motor efferent and sensory afferent signals to produce a representation of the current state of the motor system. Such a state estimate of the moving human arm would be expected to be used when the arm is rapidly and skillfully reaching to a target. We now report the effects of transcranial magnetic stimulation (TMS) over the ipsilateral cerebellum as healthy humans were made to interrupt a slow voluntary movement to rapidly reach towards a visually defined target. Errors in the initial direction and in the final finger position of this reach-to-target movement were significantly higher for cerebellar stimulation than they were in control conditions. The average directional errors in the cerebellar TMS condition were consistent with the reaching movements being planned and initiated from an estimated hand position that was 138 ms out of date. We suggest that these results demonstrate that the cerebellum is responsible for estimating the hand position over this time interval and that TMS disrupts this state estimate. PMID:18044990

Quantitative evaluation of apical extrusion of intracanal bacteria using rotary ProTaper, K3XF, twisted and hand K-file system: An ex vivo study.

PubMed

Ghogre, Priyanka; Chourasia, Hemant Ramesh; Agarwal, Manish; Singh, M P; Gurav, Sandeep; Ghogre, Rahul

2015-01-01

The aim of this study was to evaluate the number of intracanal bacteria extruded apically during root canal preparation using rotary ProTaper, K3XF, twisted, and hand K-file system. Seventy extracted single-rooted human mandibular premolar teeth were used. Access cavities were prepared and the teeth were mounted in glass vials. Root canals were then contaminated with a pure culture of Enterococcus faecalis (ATCC 29212) and incubated at 37°C for 24 h. The contaminated roots were divided into four experimental groups of 15 teeth each and one control group of 10 teeth. Group 1: ProTaper; Group 2: K3XF; Group 3: Twisted file; Group 4: Hand K-file; Group 5: Control group. Bacteria extruded from the apical foramen during instrumentation were collected into vials. The microbiological samples were incubated in culture media for 24 h. Colonies of bacteria were counted and the results were given as number of colony-forming units (CFU)/ml. The obtained data were analyzed using the Kruskal-Wallis one-way analysis of variance and Mann-Whitney U-tests. There was a significant difference between the rotary and hand instrumentation system related to the apically extruded intracanal bacteria. Both the rotary and hand instrumentation systems extruded intracanal bacteria through the apical foramen. K3XF file system showed least bacterial extrusion amongst all instrumentation groups.

Hand-transmitted vibration and biodynamic response of the human hand-arm: a critical review.

PubMed

Dong, R G; Rakheja, S; Schopper, A W; Han, B; Smutz, W P

2001-01-01

Hand-arm vibration syndrome (HAVS) has been associated with prolonged exposure to vibration transmitted to the human hand-arm system from hand-held power tools, vibrating machines, or hand-held vibrating workpieces. The biodynamic response of the human hand and arm to hand transmitted vibration (HTV) forms an essential basis for effective evaluations of exposures, vibration-attenuation mechanisms, and potential injury mechanisms. The biodynamic response to HTV and its relationship to HAVS are critically reviewed and discussed to highlight the advances and the need for further research. In view of its strong dependence on the nature of HTV and the lack of general agreement on the characteristics of HTV, the reported studies are first reviewed to enhance an understanding of HTV and related issues. The characteristics of HTV and relevant unresolved issues are discussed on the basis of measured data, proposed standards, and measurement methods, while the need for further developments in measurement systems is emphasized. The studies on biodynamic response and their findings are grouped into four categories based on the methodology used and the objective. These include studies on (1) through-the-hand-arm response, expressed in terms of vibration transmissibility; (2) to-the-hand response, expressed in terms of the force-motion relationship of the hand-arm system; (3) to-the-hand biodynamic response function, expressed in terms of vibration energy absorption; and (4) computer modeling of the biodynamic response characteristics.

The Effects of Age, Gender, and Hand on Force Control Capabilities of Healthy Adults.

PubMed

Lee, Baekhee; Lee, Mina; Yoh, Myeung Sook; You, Heecheon; Park, Hyunji; Jung, Kihyo; Lee, Byung Hwa; Na, Duk L; Kim, Geon Ha

2015-12-01

The present study examined the effects of age (20s to 70s), gender (male and female), and hand (dominant and nondominant) on force control capabilities (FCCs) in four force control phases (initiation, development, maintenance, and termination). Normative data of FCCs by force control phase are needed for various populations in age and gender to identify a type of motor performance reduction and its severity. FCCs of 360 participants (30 for each combination of age group and gender) were measured using a finger dynamometer and quantified in terms of initiation time (IT), development time (DT), maintenance error (ME), and termination time (TT). Although gradual increases (1%~28%) by age were shown in IT, DT, and TT, a dramatic increase in ME was observed among participants in their 50s (26%), 60s (68%), and 70s (160%) compared to those in their 20s~40s. The most distinctive interaction effect of age and gender was found in ME out of the four FCC measures. Lastly, hand and its related interactions were not found significant. Normative FCC data were established for four age groups (20s~40s, 50s, 60s, and 70s) and gender. The normative FCC data can be used for evaluating an individual's motor performance, screening patients with brain disorders, and designing input devices triggered and/or operated by the finger. © 2015, Human Factors and Ergonomics Society.

Collaborative real-time scheduling of multiple PTZ cameras for multiple object tracking in video surveillance

NASA Astrophysics Data System (ADS)

Liu, Yu-Che; Huang, Chung-Lin

2013-03-01

This paper proposes a multi-PTZ-camera control mechanism to acquire close-up imagery of human objects in a surveillance system. The control algorithm is based on the output of multi-camera, multi-target tracking. Three main concerns of the algorithm are (1) the imagery of human object's face for biometric purposes, (2) the optimal video quality of the human objects, and (3) minimum hand-off time. Here, we define an objective function based on the expected capture conditions such as the camera-subject distance, pan tile angles of capture, face visibility and others. Such objective function serves to effectively balance the number of captures per subject and quality of captures. In the experiments, we demonstrate the performance of the system which operates in real-time under real world conditions on three PTZ cameras.

Further information on the prehistoric representations of human hands in the cave of Gargas

PubMed Central

Hooper, Alex

1980-01-01

This paper amends and adds recent information to Paul A. Janssens' earlier article on the prehistoric paintings of human hands in the cave of Gargas, France.1 Possible diagnoses for the deficiencies found in many of the hand pictures, and some non-medical theories of explanation, are reviewed. It is concluded that the hands used as stencils were mutilated and that the images were deliberately placed within the cave and were not the by-products of some other activity. PMID:6990130

An Exoskeleton Robot for Human Forearm and Wrist Motion Assist

NASA Astrophysics Data System (ADS)

Ranathunga Arachchilage Ruwan Chandra Gopura; Kiguchi, Kazuo

The exoskeleton robot is worn by the human operator as an orthotic device. Its joints and links correspond to those of the human body. The same system operated in different modes can be used for different fundamental applications; a human-amplifier, haptic interface, rehabilitation device and assistive device sharing a portion of the external load with the operator. We have been developing exoskeleton robots for assisting the motion of physically weak individuals such as elderly or slightly disabled in daily life. In this paper, we propose a three degree of freedom (3DOF) exoskeleton robot (W-EXOS) for the forearm pronation/ supination motion, wrist flexion/extension motion and ulnar/radial deviation. The paper describes the wrist anatomy toward the development of the exoskeleton robot, the hardware design of the exoskeleton robot and EMG-based control method. The skin surface electromyographic (EMG) signals of muscles in forearm of the exoskeletons' user and the hand force/forearm torque are used as input information for the controller. By applying the skin surface EMG signals as main input signals to the controller, automatic control of the robot can be realized without manipulating any other equipment. Fuzzy control method has been applied to realize the natural and flexible motion assist. Experiments have been performed to evaluate the proposed exoskeleton robot and its control method.

Hand Path Priming in Manual Obstacle Avoidance: Evidence for Abstract Spatiotemporal Forms in Human Motor Control

ERIC Educational Resources Information Center

van der Wel, Robrecht P. R. D.; Fleckenstein, Robin M.; Jax, Steven A.; Rosenbaum, David A.

2007-01-01

Previous research suggests that motor equivalence is achieved through reliance on effector-independent spatiotemporal forms. Here the authors report a series of experiments investigating the role of such forms in the production of movement sequences. Participants were asked to complete series of arm movements in time with a metronome and, on some…

Using an Artificial Neural Bypass to Restore Cortical Control of Rhythmic Movements in a Human with Quadriplegia

PubMed Central

Sharma, Gaurav; Friedenberg, David A.; Annetta, Nicholas; Glenn, Bradley; Bockbrader, Marcie; Majstorovic, Connor; Domas, Stephanie; Mysiw, W. Jerry; Rezai, Ali; Bouton, Chad

2016-01-01

Neuroprosthetic technology has been used to restore cortical control of discrete (non-rhythmic) hand movements in a paralyzed person. However, cortical control of rhythmic movements which originate in the brain but are coordinated by Central Pattern Generator (CPG) neural networks in the spinal cord has not been demonstrated previously. Here we show a demonstration of an artificial neural bypass technology that decodes cortical activity and emulates spinal cord CPG function allowing volitional rhythmic hand movement. The technology uses a combination of signals recorded from the brain, machine-learning algorithms to decode the signals, a numerical model of CPG network, and a neuromuscular electrical stimulation system to evoke rhythmic movements. Using the neural bypass, a quadriplegic participant was able to initiate, sustain, and switch between rhythmic and discrete finger movements, using his thoughts alone. These results have implications in advancing neuroprosthetic technology to restore complex movements in people living with paralysis. PMID:27658585

Recovery of tall cotton-grass following real and simulated feeding by snow geese

USGS Publications Warehouse

Hupp, Jerry W.; Robertson, Donna G.; Schmutz, Joel A.

2000-01-01

Lesser snow geese Anser caerulescens caerulescens from the western Canadian Arctic feed on underground parts of tall cotton-grass Eriophorum angustifolium during autumn staging on the coastal plain of the Beaufort Sea in Canada and Alaska. We studied revegetation of sites where cotton-grass had been removed either by human-imprinted snow geese or by hand to simulate snow goose feeding. Aerial cover of cotton-grass at sites (n = 4) exploited by human-imprinted snow geese averaged 60 and 39% lower than in undisturbed control plots during the first and second year after feeding, respectively. Underground biomass of cotton-grass stembases and rhizomes in hand-treated plots was 80 and 62% less than in control plots 2 and 4 yr after removal, respectively (n = 10 yr-1). Aerial cover and biomass of common non-forage species such as Carex aquatilis did not increase on treated areas. Removal of cotton-grass by geese likely reduces forage availability at exploited sites for at least 2-4 yr after feeding but probably does not affect long-term community composition. Temporal heterogeneity in forage abundance likely contributes to the large spatial requirement of snow geese during staging.

Influence of mirror therapy on human motor cortex.

PubMed

Fukumura, Kenji; Sugawara, Kenichi; Tanabe, Shigeo; Ushiba, Junichi; Tomita, Yutaka

2007-07-01

This article investigates whether or not mirror therapy alters the neural mechanisms in human motor cortex. Six healthy volunteers participated. The study investigated the effects of three main factors of mirror therapy (observation of hand movements in a mirror, motor imagery of an assumed affected hand, and assistance in exercising the assumed affected hand) on excitability changes in the human motor cortex to clarify the contribution of each factor. The increase in motor-evoked potential (MEP) amplitudes during motor imagery tended to be larger with a mirror than without one. Moreover, MEP amplitudes increased greatly when movements were assisted. Watching the movement of one hand in a mirror makes it easier to move the other hand in the same way. Moreover, the increase in MEP amplitudes is related to the synergic effects of afferent information and motor imagery.

Magnetic resonance spectroscopy of current hand amputees reveals evidence for neuronal-level changes in former sensorimotor cortex

PubMed Central

Choi, In-Young; Lee, Phil; Peng, Huiling; Kaufman, Christina L.; Frey, Scott H.

2017-01-01

Deafferentation is accompanied by large-scale functional reorganization of maps in the primary sensory and motor areas of the hemisphere contralateral to injury. Animal models of deafferentation suggest a variety of cellular-level changes including depression of neuronal metabolism and even neuronal death. Whether similar neuronal changes contribute to patterns of reorganization within the contralateral sensorimotor cortex of chronic human amputees is uncertain. We used functional MRI-guided proton magnetic resonance spectroscopy to test the hypothesis that unilateral deafferentation is associated with lower levels of N-acetylaspartate (NAA, a putative marker of neuronal integrity) in the sensorimotor hand territory located contralateral to the missing hand in chronic amputees (n = 19) compared with the analogous hand territory of age- and sex-matched healthy controls (n = 28). We also tested whether former amputees [i.e., recipients of replanted (n = 3) or transplanted (n = 2) hands] exhibit NAA levels that are indistinguishable from controls, possible evidence for reversal of the effects of deafferentation. As predicted, relative to controls, current amputees exhibited lower levels of NAA that were negatively and significantly correlated with the time after amputation. Contrary to our prediction, NAA levels in both replanted and transplanted patients fell within the range of the current amputees. We suggest that lower levels of NAA in current amputees reflects altered neuronal integrity consequent to chronic deafferentation. Thus local changes in NAA levels may provide a means of assessing neuroplastic changes in deafferented cortex. Results from former amputees suggest that these changes may not be readily reversible through reafferentation. NEW & NOTEWORTHY This study is the first to use functional magnetic resonance-guided magnetic resonance spectroscopy to examine neurochemical mechanisms underlying functional reorganization in the primary somatosensory and motor cortices consequent to upper extremity amputation and its potential reversal through hand replantation or transplantation. We provide evidence for selective alteration of cortical neuronal integrity associated with amputation-related deafferentation that may not be reversible. PMID:28179478

Abnormal Sense of Agency in Patients with Schizophrenia: Evidence from Bimanual Coupling Paradigm

PubMed Central

Garbarini, Francesca; Mastropasqua, Angela; Sigaudo, Monica; Rabuffetti, Marco; Piedimonte, Alessandro; Pia, Lorenzo; Rocca, Paola

2016-01-01

A fruitful approach to the understanding the human awareness of action is the study of those pathologies in which some aspects of it are altered. Previous evidences showed that patients with schizophrenia tend to attribute someone else’ actions to their own, as internally, rather than externally, generated. Here, we asked whether schizophrenics have an “excessive” sense of agency, while observing others’ movements. We took advantage from the circles-lines task, known to show bimanual interferences. Twenty schizophrenics and 20 age-matched healthy controls were administered: (a) the bimanual version of the task: drawing lines with one hand and circles with the other; and (b) a modified version: drawing lines while observing the examiner drawing circles. In the bimanual version, patients and controls showed a comparable interference effect. In the observation version, schizophrenics, compared to controls, showed a significantly greater interference effect of the examiners’ hand drawing circles on the own hand drawing lines. This effect was significantly correlated to the strength of the positive symptoms (hallucinations and delusions) and to the alteration of the sense of agency, reported during the task. These findings suggest that an altered sense of agency, as shown by schizophrenics, can induce objective consequences on the motor system. PMID:27014005

Legal restraints of pesticide effect on human organism and environment under international legislation.

PubMed

Pashkov, Vitalii; Batyhina, Olena; Trotska, Maryna

2017-01-01

Human health depends on many factors: a level of medicine, quality of medical preparations, state of the environment, food safety, lifestyle and others. Phytosanitary products including pesticides used by farmers to kill, control reproduction and prevent animal, microbial or plant pests in the cultivation of agricultural products, which are the basis of human food, are one of the factors that may have an unfavourable effect on human health. To analyze provisions of international legislation for presence of effective means to prevent a negative pesticide effect on human health and the environment. International acts, data of international organizations and conclusions of scientists have been examined and used in the study. The article also summarizes information from scientific journals and monographs from a medical and legal point of view with scientific methods. As a part of a systematic approach, issues of the pesticide effect in the course of their use on human health and the environment are analyzed. Based on the undertaken study, it has been found that developed countries take much better care of prevention and reduction of the negative pesticide effect on human health and the environment in the course of their use than developing countries. The pesticide effect has a dual nature. On the one hand, it is positive to ensure efficient development of agriculture, but on the other hand, it is negative that is expressed in potential possibilities of harm to humans and the environment.

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

PubMed

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.

Status of infection control policies and organisation in European hospitals, 2001: the ARPAC study.

PubMed

Struelens, M J; Wagner, D; Bruce, J; MacKenzie, F M; Cookson, B D; Voss, A; van den Broek, P J; Gould, I M

2006-08-01

Patient safety in hospital care depends on effective infection control (IC) programmes. The Antimicrobial Resistance Prevention and Control (ARPAC) study assessed the organisation, components and human resources of IC programmes in European hospitals. A questionnaire survey of policies and procedures implemented in 2001 for the surveillance and control of nosocomial infection and antibiotic resistance was completed by 169 acute-care hospitals from 32 European countries, categorised by five geographical regions. A formal IC programme existed in 72% of hospitals, and a multidisciplinary IC committee was operational in 90%. Trained IC nurses (ICNs) were present in 80% of hospitals (ranging from 54% in south-east and central-eastern Europe, to 100% in northern Europe), whereas 74% had one or more trained IC doctors (ICDs) (ranging from 46% in south-east Europe to 84% in western Europe). Median staffing levels were 2.33 ICNs/1,000 beds and 0.94 ICDs/1,000 beds. The intensity of IC programmes scored higher in centres from northern and western Europe than from other European regions. Written guidelines promoted hand hygiene for healthcare workers in 89% of hospitals, education in 85%, and audit in 46%. Guidelines recommended use of alcohol-based solutions (70%) and/or medicated/antiseptic soap (43%) for decontamination of non-soiled hands. Use of alcohol-based solutions varied according to region, from 41% in southern Europe to 100% in northern Europe, compared with use of medicated soap from 77% in southern Europe to 11% in northern Europe (p < 0.01). These findings showed that IC programmes in European hospitals suffer from major deficiencies in human resources and policies. Staffing levels for ICNs were below recommended standards in the majority of hospitals. Education programmes were incomplete and often not supported by audit of performance. Hand hygiene procedures were sub-standard in one-third of centres. Strengthening of IC policies in European hospitals should be a public health priority.

Body painting to promote self-active learning of hand anatomy for preclinical medical students.

PubMed

Jariyapong, Pitchanee; Punsawad, Chuchard; Bunratsami, Suchirat; Kongthong, Paranyu

2016-01-01

Background The purpose of this study was to use the body painting method to teach hand anatomy to a group of preclinical medical students. Methods Students reviewed hand anatomy using the traditional method and body painting exercise. Feedback and retention of the anatomy-related information were examined by a questionnaire and multiple-choice questions, respectively, immediately and 1 month after the painting exercise. Results Students agreed that the exercise was advantageous and helped facilitate self-active learning after in-class anatomy lessons. While there was no significant difference in knowledge retention between the control and experimental groups, the students appreciated the exercise in which they applied body paint to the human body to learn anatomy. Conclusion The body painting was an efficient tool for aiding the interactive learning of medical students and increasing the understanding of gross anatomy.

A predictive control framework for torque-based steering assistance to improve safety in highway driving

NASA Astrophysics Data System (ADS)

Ercan, Ziya; Carvalho, Ashwin; Tseng, H. Eric; Gökaşan, Metin; Borrelli, Francesco

2018-05-01

Haptic shared control framework opens up new perspectives on the design and implementation of the driver steering assistance systems which provide torque feedback to the driver in order to improve safety. While designing such a system, it is important to account for the human-machine interactions since the driver feels the feedback torque through the hand wheel. The controller should consider the driver's impact on the steering dynamics to achieve a better performance in terms of driver's acceptance and comfort. In this paper we present a predictive control framework which uses a model of driver-in-the-loop steering dynamics to optimise the torque intervention with respect to the driver's neuromuscular response. We first validate the system in simulations to compare the performance of the controller in nominal and model mismatch cases. Then we implement the controller in a test vehicle and perform experiments with a human driver. The results show the effectiveness of the proposed system in avoiding hazardous situations under different driver behaviours.

Multi-muscle FES force control of the human arm for arbitrary goals.

PubMed

Schearer, Eric M; Liao, Yu-Wei; Perreault, Eric J; Tresch, Matthew C; Memberg, William D; Kirsch, Robert F; Lynch, Kevin M

2014-05-01

We present a method for controlling a neuroprosthesis for a paralyzed human arm using functional electrical stimulation (FES) and characterize the errors of the controller. The subject has surgically implanted electrodes for stimulating muscles in her shoulder and arm. Using input/output data, a model mapping muscle stimulations to isometric endpoint forces measured at the subject's hand was identified. We inverted the model of this redundant and coupled multiple-input multiple-output system by minimizing muscle activations and used this inverse for feedforward control. The magnitude of the total root mean square error over a grid in the volume of achievable isometric endpoint force targets was 11% of the total range of achievable forces. Major sources of error were random error due to trial-to-trial variability and model bias due to nonstationary system properties. Because the muscles working collectively are the actuators of the skeletal system, the quantification of errors in force control guides designs of motion controllers for multi-joint, multi-muscle FES systems that can achieve arbitrary goals.

A new six-degree-of-freedom force-reflecting hand controller for space telerobotics

NASA Technical Reports Server (NTRS)

Mcaffee, Douglas; Snow, Edward; Townsend, William; Robinson, Lee; Hanson, Joe

1990-01-01

A new 6 degree of freedom universal Force Reflecting Hand Controller (FRHC) was designed for use as the man-machine interface in teleoperated and telerobotic flight systems. The features of this new design include highly intuitive operation, excellent kinesthetic feedback, high fidelity force/torque feedback, a kinematically simple structure, mechanically decoupled motion in all 6 DOF, good back-drivability, and zero backlash. In addition, the new design has a much larger work envelope, smaller stowage volume, greater stiffness and responsiveness, and better overlap of the human operator's range of motion than do previous designs. The utility and basic operation of a new, flight prototype FRHC called the Model X is briefly discussed. The design heritage, general design goals, and design implementation of this advanced new generation of FRHCs are presented, followed by a discussion of basic features and the results of initial testing.

Does the brain use sliding variables for the control of movements?

PubMed

Hanneton, S; Berthoz, A; Droulez, J; Slotine, J J

1997-12-01

Delays in the transmission of sensory and motor information prevent errors from being instantaneously available to the central nervous system (CNS) and can reduce the stability of a closed-loop control strategy. On the other hand, the use of a pure feedforward control (inverse dynamics) requires a perfect knowledge of the dynamic behavior of the body and of manipulated objects. Sensory feedback is essential both to accommodate unexpected errors and events and to compensate for uncertainties about the dynamics of the body. Experimental observations concerning the control of posture, gaze and limbs have shown that the CNS certainly uses a combination of closed-loop and open-loop control. Feedforward components of movement, such as eye saccades, occur intermittently and present a stereotyped kinematic profile. In visuo-manual tracking tasks, hand movements exhibit velocity peaks that occur intermittently. When a delay or a slow dynamics are inserted in the visuo-manual control loop, intermittent step-and-hold movements appear clearly in the hand trajectory. In this study, we investigated strategies used by human subjects involved in the control of a particular dynamic system. We found strong evidence for substantial nonlinearities in the commands produced. The presence of step-and-hold movements seemed to be the major source of nonlinearities in the control loop. Furthermore, the stereotyped ballistic-like kinematics of these rapid and corrective movements suggests that they were produced in an open-loop way by the CNS. We analyzed the generation of ballistic movements in the light of sliding control theory assuming that they occurred when a sliding variable exceeded a constant threshold. In this framework, a sliding variable is defined as a composite variable (a combination of the instantaneous tracking error and its temporal derivatives) that fulfills a specific stability criterion. Based on this hypothesis and on the assumption of a constant reaction time, the tracking error and its derivatives should be correlated at a particular time lag before movement onset. A peak of correlation was found for a physiologically plausible reaction time, corresponding to a stable composite variable. The direction and amplitude of the ongoing stereotyped movements seemed also be adjusted in order to minimize this variable. These findings suggest that, during visually guided movements, human subjects attempt to minimize such a composite variable and not the instantaneous error. This minimization seems to be obtained by the execution of stereotyped corrective movements.

Mouse models for human hair loss disorders

PubMed Central

Porter, Rebecca M

2003-01-01

The outer surface of the hand, limb and body is covered by the epidermis, which is elaborated into a number of specialized appendages, evolved not only to protect and reinforce the skin but also for social signalling. The most prominent of these appendages is the hair follicle. Hair follicles are remarkable because of their prolific growth characteristics and their complexity of differentiation. After initial embryonic morphogenesis, the hair follicle undergoes repeated cycles of regression and regeneration throughout the lifetime of the organism. Studies of mouse mutants with hair loss phenotypes have suggested that the mechanisms controlling the hair cycle probably involve many of the major signalling molecules used elsewhere in development, although the complete pathway of hair follicle growth control is not yet understood. Mouse studies have also led to the discovery of genes underlying several human disorders. Future studies of mouse hair-loss mutants are likely to benefit the understanding of human hair loss as well as increasing our knowledge of mechanisms controlling morphogenesis and tumorigenesis. PMID:12587927

Differential effect of muscle vibration on intracortical inhibitory circuits in humans

PubMed Central

Rosenkranz, Karin; Rothwell, John C

2003-01-01

Low amplitude muscle vibration (0.5 ms; 80 Hz; duration 1.5 s) was applied in turn to each of three different intrinsic hand muscles (first dorsal interosseus, FDI; abductor pollicis brevis, APB; and abductor digiti minimi, ADM) in order to test its effect on the EMG responses evoked by transcranial magnetic stimulation (TMS). Recordings were also taken from flexor and extensor carpi radialis (FCR and ECR, respectively). We evaluated the amplitude of motor evoked potentials (MEPs) produced by a single TMS pulse, short interval intracortical inhibition and facilitation (SICI and ICF) and long interval intracortical inhibition (LICI). TMS pulses were applied 1 s after the start of vibration with subjects relaxed throughout. Vibration increased the amplitude of MEPs evoked in the vibrated muscle (162 ± 6 % of MEP with no vibration; mean ± s.e.m.), but suppressed MEPs in the two non-vibrated hand muscles (72 ± 9 %). Compared with no vibration (test response reduced to 51 ± 5 % of control), there was less SICI in the vibrated muscle (test response reduced to 92 ± 28 % of control) and more in the non-vibrated hand muscles (test response reduced to 27 ± 5 % of control). The opposite occurred for LICI: compared with the no vibration condition (test response reduced to 33 ± 6 % control), there was more LICI in the vibrated muscle (test response reduced to 17 ± 3 % control) than in the non-vibrated hand muscles (test response reduced to 80 ± 11 % control) even when the intensity of the test stimulus was adjusted to compensate for the changes in baseline MEP. There was no effect on ICF. Cutaneous stimulation of the index finger (80 Hz, 1.5 s duration, twice sensory threshold) had no consistent differential effect on any of the parameters. We conclude that vibratory input from muscle can differentially modulate excitability in motor cortical circuits. PMID:12821723

The hand of Homo naledi.

PubMed

Kivell, Tracy L; Deane, Andrew S; Tocheri, Matthew W; Orr, Caley M; Schmid, Peter; Hawks, John; Berger, Lee R; Churchill, Steven E

2015-10-06

A nearly complete right hand of an adult hominin was recovered from the Rising Star cave system, South Africa. Based on associated hominin material, the bones of this hand are attributed to Homo naledi. This hand reveals a long, robust thumb and derived wrist morphology that is shared with Neandertals and modern humans, and considered adaptive for intensified manual manipulation. However, the finger bones are longer and more curved than in most australopiths, indicating frequent use of the hand during life for strong grasping during locomotor climbing and suspension. These markedly curved digits in combination with an otherwise human-like wrist and palm indicate a significant degree of climbing, despite the derived nature of many aspects of the hand and other regions of the postcranial skeleton in H. naledi.

[Beta-endorphin and obesity. Possible pathogenetic implications].

PubMed

Giugliano, D; Saccomanno, F; Quatraro, A; Ceriello, A; Torella, R

1990-01-01

Several experimental data have documented the ability of both opiates and opioid peptides to stimulate food intake. On the other hand, the plasma beta-endorphin levels found in obese patients are higher than those observed in normal-weight controls, which may have pathogenetic implications. We have investigated the responses of plasma glucose, insulin, C-peptide and glucagon to an infusion of human beta-endorphin in formerly obese subjects who had obtained by dieting the normalization of body weight and in lean controls. The data show that: a) the increased plasma beta-endorphin concentrations found in human obesity are not corrected by normalization of body weight; b) formerly obese subjects behave as obese subjects in their metabolic and hormonal responses to beta-endorphin.

Mapping From an Instrumented Glove to a Robot Hand

NASA Technical Reports Server (NTRS)

Goza, Michael

2005-01-01

An algorithm has been developed to solve the problem of mapping from (1) a glove instrumented with joint-angle sensors to (2) an anthropomorphic robot hand. Such a mapping is needed to generate control signals to make the robot hand mimic the configuration of the hand of a human attempting to control the robot. The mapping problem is complicated by uncertainties in sensor locations caused by variations in sizes and shapes of hands and variations in the fit of the glove. The present mapping algorithm is robust in the face of these uncertainties, largely because it includes a calibration sub-algorithm that inherently adapts the mapping to the specific hand and glove, without need for measuring the hand and without regard for goodness of fit. The algorithm utilizes a forward-kinematics model of the glove derived from documentation provided by the manufacturer of the glove. In this case, forward-kinematics model signifies a mathematical model of the glove fingertip positions as functions of the sensor readings. More specifically, given the sensor readings, the forward-kinematics model calculates the glove fingertip positions in a Cartesian reference frame nominally attached to the palm. The algorithm also utilizes an inverse-kinematics model of the robot hand. In this case, inverse-kinematics model signifies a mathematical model of the robot finger-joint angles as functions of the robot fingertip positions. Again, more specifically, the inverse-kinematics model calculates the finger-joint commands needed to place the fingertips at specified positions in a Cartesian reference frame that is attached to the palm of the robot hand and that nominally corresponds to the Cartesian reference frame attached to the palm of the glove. Initially, because of the aforementioned uncertainties, the glove fingertip positions calculated by the forwardkinematics model in the glove Cartesian reference frame cannot be expected to match the robot fingertip positions in the robot-hand Cartesian reference frame. A calibration must be performed to make the glove and robot-hand fingertip positions correspond more precisely. The calibration procedure involves a few simple hand poses designed to provide well-defined fingertip positions. One of the poses is a fist. In each of the other poses, a finger touches the thumb. The calibration subalgorithm uses the sensor readings from these poses to modify the kinematical models to make the two sets of fingertip positions agree more closely.

Relationship between speed and EEG activity during imagined and executed hand movements

NASA Astrophysics Data System (ADS)

Yuan, Han; Perdoni, Christopher; He, Bin

2010-04-01

The relationship between primary motor cortex and movement kinematics has been shown in nonhuman primate studies of hand reaching or drawing tasks. Studies have demonstrated that the neural activities accompanying or immediately preceding the movement encode the direction, speed and other information. Here we investigated the relationship between the kinematics of imagined and actual hand movement, i.e. the clenching speed, and the EEG activity in ten human subjects. Study participants were asked to perform and imagine clenching of the left hand and right hand at various speeds. The EEG activity in the alpha (8-12 Hz) and beta (18-28 Hz) frequency bands were found to be linearly correlated with the speed of imagery clenching. Similar parametric modulation was also found during the execution of hand movements. A single equation relating the EEG activity to the speed and the hand (left versus right) was developed. This equation, which contained a linear independent combination of the two parameters, described the time-varying neural activity during the tasks. Based on the model, a regression approach was developed to decode the two parameters from the multiple-channel EEG signals. We demonstrated the continuous decoding of dynamic hand and speed information of the imagined clenching. In particular, the time-varying clenching speed was reconstructed in a bell-shaped profile. Our findings suggest an application to providing continuous and complex control of noninvasive brain-computer interface for movement-impaired paralytics.

Combining heterogenous features for 3D hand-held object recognition

NASA Astrophysics Data System (ADS)

Lv, Xiong; Wang, Shuang; Li, Xiangyang; Jiang, Shuqiang

2014-10-01

Object recognition has wide applications in the area of human-machine interaction and multimedia retrieval. However, due to the problem of visual polysemous and concept polymorphism, it is still a great challenge to obtain reliable recognition result for the 2D images. Recently, with the emergence and easy availability of RGB-D equipment such as Kinect, this challenge could be relieved because the depth channel could bring more information. A very special and important case of object recognition is hand-held object recognition, as hand is a straight and natural way for both human-human interaction and human-machine interaction. In this paper, we study the problem of 3D object recognition by combining heterogenous features with different modalities and extraction techniques. For hand-craft feature, although it reserves the low-level information such as shape and color, it has shown weakness in representing hiconvolutionalgh-level semantic information compared with the automatic learned feature, especially deep feature. Deep feature has shown its great advantages in large scale dataset recognition but is not always robust to rotation or scale variance compared with hand-craft feature. In this paper, we propose a method to combine hand-craft point cloud features and deep learned features in RGB and depth channle. First, hand-held object segmentation is implemented by using depth cues and human skeleton information. Second, we combine the extracted hetegerogenous 3D features in different stages using linear concatenation and multiple kernel learning (MKL). Then a training model is used to recognize 3D handheld objects. Experimental results validate the effectiveness and gerneralization ability of the proposed method.

A GPU-accelerated cortical neural network model for visually guided robot navigation.

PubMed

Beyeler, Michael; Oros, Nicolas; Dutt, Nikil; Krichmar, Jeffrey L

2015-12-01

Humans and other terrestrial animals use vision to traverse novel cluttered environments with apparent ease. On one hand, although much is known about the behavioral dynamics of steering in humans, it remains unclear how relevant perceptual variables might be represented in the brain. On the other hand, although a wealth of data exists about the neural circuitry that is concerned with the perception of self-motion variables such as the current direction of travel, little research has been devoted to investigating how this neural circuitry may relate to active steering control. Here we present a cortical neural network model for visually guided navigation that has been embodied on a physical robot exploring a real-world environment. The model includes a rate based motion energy model for area V1, and a spiking neural network model for cortical area MT. The model generates a cortical representation of optic flow, determines the position of objects based on motion discontinuities, and combines these signals with the representation of a goal location to produce motor commands that successfully steer the robot around obstacles toward the goal. The model produces robot trajectories that closely match human behavioral data. This study demonstrates how neural signals in a model of cortical area MT might provide sufficient motion information to steer a physical robot on human-like paths around obstacles in a real-world environment, and exemplifies the importance of embodiment, as behavior is deeply coupled not only with the underlying model of brain function, but also with the anatomical constraints of the physical body it controls. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Drawing of the family and of the human figure: a comparative study between children with epilepsy and a control group].

PubMed

Gomes-Correia, A

In this study our aim was to get to know children with epilepsy through their drawings. In this case the drawings of the human figure and the family were chosen. The population which was studied included 32 children: 16 of these children had epilepsy and the 16 others were the control group. From the comparison performed between these two groups of children it was found that in relation to family drawings children with epilepsy tend more to draw their own family than children in the control group. As for the drawing of the human figure and the global analysis of the body figure it was found that the mental age of the isolated character and the higher level character drawn by epileptic children was inferior to chronological age, while the reverse was true in the drawings of the control group. In relation to the analysis of structural cohesion in the representation of the body it was found that hands were absent in the drawings of epileptic children.

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

PubMed Central

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

2015-01-01

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 partial-hand applications. PMID:25955989

[Is abortion murder?].

PubMed

Werning, C

1995-09-01

Discussions about Paragraph 218 of the German federal abortion law have spawned antithetical opinions: on the one hand, the full right of the mother or parents to decide about the incipient human life; and on the other hand, under the dogma of abortion is murder, providing abortion is rejected even when the pregnancy is the result of rape and it is unwanted. Two questions are closely related to this issue: 1) what makes human beings human and 2) when does human life begin. From a medical point of view the function of the brain is fundamentally linked to being human. The brain controls almost all functions of the body and determines its psychological makeup, such as intellect and, in a theological sense, the soul. Without the brain such functioning is not possible, since brain death means the death of human life. Children born with anencephaly and microencephaly can never live a human life. At the end of life various diseases (stroke, Alzheimer disease) can severely damage the brain. In these cases normal living is also no longer possible. Yet ethically it is untenable to actively kill these human beings. But when one considers that life-threatening diseases can require life-support intervention, then often the pragmatic intervention is not far removed from active euthanasia. The other question related to the beginning of human life is even more difficult to answer. It is the fertilization of the egg cells; but a conglomeration of cells in the early phase of pregnancy can hardly be characterized as a human person. The human identity, personality, and worth is associated with the functioning of the brain, so only when the brain is fully developed can there be any talk about an unborn human being.

Acute Exposure to Stress Improves Performance in Trace Eyeblink Conditioning and Spatial Learning Tasks in Healthy Men

ERIC Educational Resources Information Center

Duncko, Roman; Cornwell, Brian; Cui, Lihong; Merikangas, Kathleen R.; Grillon, Christian

2007-01-01

The present study investigated the effects of acute stress exposure on learning performance in humans using analogs of two paradigms frequently used in animals. Healthy male participants were exposed to the cold pressor test (CPT) procedure, i.e., insertion of the dominant hand into ice water for 60 sec. Following the CPT or the control procedure,…

Finger length ratio (2D:4D) in adults with gender identity disorder.

PubMed

Kraemer, Bernd; Noll, Thomas; Delsignore, Aba; Milos, Gabriella; Schnyder, Ulrich; Hepp, Urs

2009-06-01

From early childhood, gender identity and the 2nd to 4th finger length ratio (2D:4D) are discriminative characteristics between sexes. Both the human brain and 2D:4D may be influenced by prenatal testosterone levels. This calls for an examination of 2D:4D in patients with gender identity disorder (GID) to study the possible influence of prenatal testosterone on gender identity. Until now, the only study carried out on this issue suggests lower prenatal testosterone levels in right-handed male-to-female GID patients (MtF). We compared 2D:4D of 56 GID patients (39 MtF; 17 female-to-male GID patients, FtM) with data from a control sample of 176 men and 190 women. Bivariate group comparisons showed that right hand 2D:4D in MtF was significantly higher (feminized) than in male controls, but similar to female controls. The comparison of 2D:4D ratios of biological women revealed significantly higher (feminized) values for right hands of right handed FtM. Analysis of variance confirmed significant effects for sex and for gender identity on 2D:4D ratios but not for sexual orientation or for the interaction among variables. Our results indirectly point to the possibility of a weak influence of reduced prenatal testosterone as an etiological factor in the multifactorially influenced development of MtF GID. The development of FtM GID seems even more unlikely to be notably influenced by prenatal testosterone.

Sensorimotor performance and function in people with osteoarthritis of the hand: A case-control comparison.

PubMed

Magni, Nicoló Edoardo; McNair, Peter John; Rice, David Andrew

2018-04-01

To determine whether hand left/right judgements, tactile acuity, and body perception are impaired in people with hand OA. To examine the relationships between left right judgements, tactile acuity and hand pain. To explore the relationships between sensorimotor measures (left/right judgements and tactile acuity) and measures of hand function in people with hand OA. Twenty patients with symptomatic hand OA and 19 healthy pain-free controls undertook a hand left/right judgment task, a control left/right judgement task, two-point discrimination (TPD) threshold testing (assessing tactile acuity), a neglect-like symptoms questionnaire (assessing body perception) and several established measures of hand function. Neglect-like symptoms were experienced more frequently in the hand OA group (P < 0.05). People with hand OA were slower (P < 0.05) and less accurate (P < 0.05) in the hand left/right judgement task when compared to healthy controls, with no significant difference in the control task. Significant associations were found between hand left/right judgement reaction time and pain intensity (P < 0.05) and accuracy and pain intensity (P < 0.05). TPD was not different between groups, and no correlation was found between TPD and left/right judgement performance. No association was found between left/right judgement performance and measures of hand function (all P > 0.05). However, TPD (tactile acuity) was related to several measures of hand function (all P < 0.05). People with hand OA had more frequent neglect-like symptoms and were slower and less accurate compared to healthy controls at hand left/right judgments, which was indicative of disrupted working body schema. Future studies may wish to examine whether interventions targeting sensorimotor dysfunction are effective at reducing pain and improving hand function and dexterity in people with hand OA. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Multidigit movement synergies of the human hand in an unconstrained haptic exploration task.

PubMed

Thakur, Pramodsingh H; Bastian, Amy J; Hsiao, Steven S

2008-02-06

Although the human hand has a complex structure with many individual degrees of freedom, joint movements are correlated. Studies involving simple tasks (grasping) or skilled tasks (typing or finger spelling) have shown that a small number of combined joint motions (i.e., synergies) can account for most of the variance in observed hand postures. However, those paradigms evoked a limited set of hand postures and as such the reported correlation patterns of joint motions may be task-specific. Here, we used an unconstrained haptic exploration task to evoke a set of hand postures that is representative of most naturalistic postures during object manipulation. Principal component analysis on this set revealed that the first seven principal components capture >90% of the observed variance in hand postures. Further, we identified nine eigenvectors (or synergies) that are remarkably similar across multiple subjects and across manipulations of different sets of objects within a subject. We then determined that these synergies are used broadly by showing that they account for the changes in hand postures during other tasks. These include hand motions such as reach and grasp of objects that vary in width, curvature and angle, and skilled motions such as precision pinch. Our results demonstrate that the synergies reported here generalize across tasks, and suggest that they represent basic building blocks underlying natural human hand motions.

Probabilistic somatotopy of the spinothalamic pathway at the ventroposterolateral nucleus of the thalamus in the human brain.

PubMed

Hong, J H; Kwon, H G; Jang, S H

2011-08-01

The STP has been regarded as the most plausible neural tract responsible for pathogenesis of central poststroke pain. The VPL nucleus has been a target for neurosurgical procedures for control of central poststroke pain. However, to our knowledge, no DTI studies have been conducted to investigate the somatotopic location of the STP at the VPL nucleus of the thalamus. In the current study, we attempted to investigate this location in the human brain by using a probabilistic tractography technique of DTI. DTI was performed at 1.5T by using a Synergy-L SENSE head coil. STPs for both the hand and leg were obtained by selection of fibers passing through 2 regions of interest (the area of the spinothalamic tract in the posterolateral medulla and the postcentral gyrus) for 41 healthy volunteers. Somatotopic mapping was obtained from the highest probabilistic location at the ACPC level. The highest probabilistic locations for the hand and leg were an average of 16.86 and 16.37 mm lateral to the ACPC line and 7.53 and 8.71 mm posterior to the midpoint of the ACPC line, respectively. Somatotopic locations for the hand and leg were different in the anteroposterior direction (P < .05); however, no difference was observed in the mediolateral direction (P > .05). We found the somatotopic locations for hand and leg of the STP at the VPL nucleus; these somatotopies were arranged in the anteroposterior direction.

Mechanical properties of the human hand digits: Age-related differences

PubMed Central

Park, Jaebum; Pazin, Nemanja; Friedman, Jason; Zatsiorsky, Vladimir M.; Latash, Mark L.

2014-01-01

Background Mechanical properties of human digits may have significant implications for the hand function. We quantified several mechanical characteristics of individual digits in young and older adults. Methods Digit tip friction was measured at several normal force values using a method of induced relative motion between the digit tip and the object surface. A modified quick-release paradigm was used to estimate digit apparent stiffness, damping, and inertial parameters. The subjects grasped a vertical handle instrumented with force/moment sensors using a prismatic grasp with four digits; the handle was fixed to the table. Unexpectedly, one of the sensors yielded leading to a quick displacement of the corresponding digit. A second-order, linear model was used to fit the force/displacement data. Findings Friction of the digit pads was significantly lower in older adults. The apparent stiffness coefficient values were higher while the damping coefficients were lower in older adults leading to lower damping ratio. The damping ratio was above unity for most data in young adults and below unity for older adults. Quick release of a digit led to force changes in other digits of the hand, likely due to inertial hand properties. These phenomena of “mechanical enslaving” were smaller in older adults although no significant difference was found in the inertial parameter in the two groups. Interpretations The decreased friction and damping ratio present challenges for the control of everyday prehensile tasks. They may lead to excessive digit forces and low stability of the grasped object. PMID:24355703

Infrared thermography based studies on the effect of age on localized cold stress induced thermoregulation in human

NASA Astrophysics Data System (ADS)

Lahiri, B. B.; Bagavathiappan, S.; Nishanthi, K.; Mohanalakshmi, K.; Veni, L.; Saumya; Yacin, S. M.; Philip, John

2016-05-01

Thermoregulatory control of blood flow plays an important role in maintaining the human body temperature and it provides physiological resistance against extreme environmental thermal stresses. To understand the role of age on thermal signals from veins and the thermoregulatory mechanism, the dynamic variation of the vein temperature on the hands of 17 human subjects, under a localized cold stress, was studied using infrared thermography. It was observed that the vein temperature of the stimulated hand initially decreased with time up to a time interval (called 'inversion time'), which was attributed to the localized cutaneous vasoconstriction. Beyond inversion time, a rise in the vein temperature of the stimulated hand was observed. A shift in the inversion time to higher values was observed for the older subjects, which was attributed to the reduced efficiency and responsiveness of the cutaneous vasoconstriction mechanism in these subjects. Our studies indicated that the inversion time increased linearly with subject age with strong positive Pearson's correlation coefficient of 0.94. It was also observed that the contralateral symmetry in vasoconstriction was much lower in older subjects than the younger subjects. The absolute difference between the left and right inversion time varied between 11-118 s and 5-28 s for the older and younger subjects, respectively. Our study clearly demonstrated that infrared thermography is one of the most effective experimental tool for studying dynamic variation in vein pixel temperature under localized thermal stresses.

Soft, Conformal Bioelectronics for a Wireless Human-Wheelchair Interface

PubMed Central

Mishra, Saswat; Norton, James J. S.; Lee, Yongkuk; Lee, Dong Sup; Agee, Nicolas; Chen, Yanfei; Chun, Youngjae; Yeo, Woon-Hong

2017-01-01

There are more than 3 million people in the world whose mobility relies on wheelchairs. Recent advancement on engineering technology enables more intuitive, easy-to-use rehabilitation systems. A human-machine interface that uses non-invasive, electrophysiological signals can allow a systematic interaction between human and devices; for example, eye movement-based wheelchair control. However, the existing machine-interface platforms are obtrusive, uncomfortable, and often cause skin irritations as they require a metal electrode affixed to the skin with a gel and acrylic pad. Here, we introduce a bioelectronic system that makes dry, conformal contact to the skin. The mechanically comfortable sensor records high-fidelity electrooculograms, comparable to the conventional gel electrode. Quantitative signal analysis and infrared thermographs show the advantages of the soft biosensor for an ergonomic human-machine interface. A classification algorithm with an optimized set of features shows the accuracy of 94% with five eye movements. A Bluetooth-enabled system incorporating the soft bioelectronics demonstrates a precise, hands-free control of a robotic wheelchair via electrooculograms. PMID:28152485

Wireless radio channel for intramuscular electrode implants in the control of upper limb prostheses.

PubMed

Stango, Antonietta; Yazdandoost, Kamya Yekeh; Farina, Dario

2015-01-01

In the last few years the use of implanted devices has been considered also in the field of myoelectric hand prostheses. Wireless implanted EMG (Electromyogram) sensors can improve the functioning of the prosthesis, providing information without the disadvantage of the wires, and the usability by amputees. The solutions proposed in the literature are based on proprietary communication protocols between the implanted devices and the prosthesis controller, using frequency bands that are already assigned to other purposes. This study proposes the use of a standard communication protocol (IEEE 802.15.6), specific for wireless body area networks (WBANs), which assign a specific bandwidth to implanted devices. The propagation losses from in-to-on body were investigated by numerical simulation with a 3D human model and an electromagnetic solver. The channel model resulting from the study represents the first step towards the development of myoelectric prosthetic hands which are driven by signals acquired by implanted sensors. However these results can provide important information to researchers for further developments, and manufacturers, which can decrease the production costs for hand prostheses having a common standard of communication with assigned frequencies of operation.

Top-down modulation of motor priming by belief about animacy.

PubMed

Liepelt, Roman; Brass, Marcel

2010-01-01

There is recent evidence that we directly map observed actions of other agents onto our own motor repertoire, referred to as direct matching (Iacoboni et al., 1999). This was shown when we are actively engaged in joint action with others' (Sebanz et al. 2003) and also when observing irrelevant movements while executing congruent or incongruent movements (Brass et al., 2000). However, an open question is whether direct matching in human beings is limited to the perception of intentional agents. Recent research provides contradictory evidence with respect to the question whether the direct matching system has a biological bias possibly emerging from perceptual differences of the stimulus display. In this study all participants performed a motor priming task observing the identical animation showing finger lifting movements of a hand in a leather glove. Before running the experiment we presented either a human hand or a wooden analog hand wearing the leather glove. We found a motor priming effect for both human and wooden hands. However, motor priming was larger when participants believed that they interacted with a human hand than when they believed to interact with a wooden hand. The stronger motor priming effect for the biological agent suggests that the "direct matching system" is tuned to represent actions of animate agents.

Data-driven grasp synthesis using shape matching and task-based pruning.

PubMed

Li, Ying; Fu, Jiaxin L; Pollard, Nancy S

2007-01-01

Human grasps, especially whole-hand grasps, are difficult to animate because of the high number of degrees of freedom of the hand and the need for the hand to conform naturally to the object surface. Captured human motion data provides us with a rich source of examples of natural grasps. However, for each new object, we are faced with the problem of selecting the best grasp from the database and adapting it to that object. This paper presents a data-driven approach to grasp synthesis. We begin with a database of captured human grasps. To identify candidate grasps for a new object, we introduce a novel shape matching algorithm that matches hand shape to object shape by identifying collections of features having similar relative placements and surface normals. This step returns many grasp candidates, which are clustered and pruned by choosing the grasp best suited for the intended task. For pruning undesirable grasps, we develop an anatomically-based grasp quality measure specific to the human hand. Examples of grasp synthesis are shown for a variety of objects not present in the original database. This algorithm should be useful both as an animator tool for posing the hand and for automatic grasp synthesis in virtual environments.

Current direction-dependent modulation of human hand motor function by intermittent theta burst stimulation (iTBS).

PubMed

Shirota, Yuichiro; Dhaka, Suman; Paulus, Walter; Sommer, Martin

2017-05-22

Transcranial magnetic stimulation (TMS) with different current directions can activate different sets of neurons. Current direction can also affect the results of repetitive TMS. To test the influence of uni-directional intermittent theta burst stimulation (iTBS) using different current directions, namely posteroanterior (PA) and anteroposterior (AP), on motor behaviour. In a cross-over design, PA- and AP-iTBS was applied over the left primary motor cortex in 19 healthy, right-handed volunteers. Performance of a finger-tapping task was recorded before and 0, 10, 20, and 30min after the iTBS. The task was conducted with the right and left hands separately at each time point. As a control, AP-iTBS with reduced intensity was applied to 14 participants in a separate session (AP weak condition). The finger-tapping count with the left hand was decreased after PA-iTBS. Neither AP- nor AP weak -iTBS altered the performance. Current direction had a significant impact on the after-effects of iTBS. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessment of electrosurgical hand controls integrated into a laparoscopic grasper.

PubMed

Brown-Clerk, Bernadette; Rousek, Justin B; Lowndes, Bethany R; Eikhout, Sandra M; Balogh, Bradley J; Hallbeck, M Susan

2011-12-01

The aim of this study was to quantitatively and qualitatively determine the optimal ergonomic placement of novel electrosurgical hand controls integrated into a standard laparoscopic grasper to optimize functionality. This device will allow laparoscopic surgeons to hand-operate standard electrosurgical equipment, eliminating the use of electrosurgical foot pedals, which are prone to activation errors and cause uncomfortable body positions for the physician. Three hand control designs were evaluated by 26 participants during the performance of four basic inanimate laparoscopic electrosurgical tasks. Task completion time, actuation force, forearm electromyography (EMG) and user preference were evaluated for each hand control design. Task speed was controlled using a metronome to minimize subject variability, and resulted in no significant completion time differences between task types (P > 0.05). Hand control design 1 (CD 1) resulted in the ability to generate significantly greater actuation force for three of the four tasks (P < 0.05) with minimal forearm muscle activation. Additionally, CD 1 was rated significantly better for comfort and ease-of-use compared to the other two hand control designs (P < 0.05). As a result, CD 1 was determined to be an advantageous ergonomic design for the novel electrosurgical hand controls.

The hand of Homo naledi

PubMed Central

Kivell, Tracy L.; Deane, Andrew S.; Tocheri, Matthew W.; Orr, Caley M.; Schmid, Peter; Hawks, John; Berger, Lee R.; Churchill, Steven E.

2015-01-01

A nearly complete right hand of an adult hominin was recovered from the Rising Star cave system, South Africa. Based on associated hominin material, the bones of this hand are attributed to Homo naledi. This hand reveals a long, robust thumb and derived wrist morphology that is shared with Neandertals and modern humans, and considered adaptive for intensified manual manipulation. However, the finger bones are longer and more curved than in most australopiths, indicating frequent use of the hand during life for strong grasping during locomotor climbing and suspension. These markedly curved digits in combination with an otherwise human-like wrist and palm indicate a significant degree of climbing, despite the derived nature of many aspects of the hand and other regions of the postcranial skeleton in H. naledi. PMID:26441219

49 CFR 236.6 - Hand-operated switch equipped with switch circuit controller.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Hand-operated switch equipped with switch circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.6 Hand-operated switch equipped with switch circuit controller. Hand-operated switch equipped with switch circuit controller connected to the...

49 CFR 236.6 - Hand-operated switch equipped with switch circuit controller.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Hand-operated switch equipped with switch circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.6 Hand-operated switch equipped with switch circuit controller. Hand-operated switch equipped with switch circuit controller connected to the...

49 CFR 236.6 - Hand-operated switch equipped with switch circuit controller.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Hand-operated switch equipped with switch circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.6 Hand-operated switch equipped with switch circuit controller. Hand-operated switch equipped with switch circuit controller connected to the...

49 CFR 236.6 - Hand-operated switch equipped with switch circuit controller.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Hand-operated switch equipped with switch circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.6 Hand-operated switch equipped with switch circuit controller. Hand-operated switch equipped with switch circuit controller connected to the...

49 CFR 236.6 - Hand-operated switch equipped with switch circuit controller.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Hand-operated switch equipped with switch circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.6 Hand-operated switch equipped with switch circuit controller. Hand-operated switch equipped with switch circuit controller connected to the...

Parallel controller construction for a multi-DOF hand rehabilitation equipment

NASA Astrophysics Data System (ADS)

Ito, Satoshi; Ueki, Satoshi; Ishihara, Koji; Miura, Masayuki; Kawasaki, Haruhisa; Ishigure, Yasuhiko; Nishimoto, Yutakai

2007-12-01

This paper describes the development of a hand rehabilitation system for stroke patients. Our aim is to provide fine motion exercise for a hand and fingers. Thus, a hand rehabilitation device that assists patients' finger movements was developed. Because this device has 18 degrees of freedom of motion, it is diffcult for disabled patients to use it by themselves. Therefore, an appropriate control strategy and control system are required to allow its safe and effective use. In light of this requirement, a control system was constructed which is comprised of four separated controllers. This paper presents the structure of the control system and introduces the control protocols used in our hand rehabilitation system.

Effects of a hypocaloric diet on obesity biomarkers: prevention of low-grade inflammation since childhood.

PubMed

Amati, L; Marzulli, G; Martulli, M; Chiloiro, M; Jirillo, E

2010-01-01

Body mass index (BMI), serum cytokines and serum obesity markers were evaluated in 33 obese children before, during and after a hypocaloric diet. The cytometric bead array "human inflammatory kit" was used for the evaluation of serum interleukin (IL)-1beta, IL-6, IL-10 and tumor necrosis factor-alpha. On the other hand, the following obesity biomarkers were evaluated by means of a flowcytomix-human obesity 9 plex kit: Soluble Isoform of CD40 Ligand; Soluble Intercellular Adhesion Molecule-1; Leptin; Monocyte Chemoattractant Protein 1; Myeloperoxidase; Osteoprotegerin; Resistin and Soluble TNF-receptors. Actually, throughout the study modifications of BMI were negligible and, therefore, serum cytokines and obesity markers did not show any significant changes in comparison with baseline values. On the other hand, at the different time points considered the majority of obesity markers were higher than normal controls, thus indicating a low grade inflammation in childhood obesity. Therefore, attempts at reducing this inflammatory status in children which predisposes to the metabolic syndrome outcome are discussed.

Survival of influenza virus on hands and fomites in community and laboratory settings.

PubMed

Mukherjee, Dhritiman V; Cohen, Bevin; Bovino, Mary Ellen; Desai, Shailesh; Whittier, Susan; Larson, Elaine L

2012-09-01

Transmission dynamics modeling provides a practical method for virtual evaluation of the impact of public health interventions in response to prospective influenza pandemics and also may help determine the relative contribution of different modes of transmission to overall infection rates. Accurate estimates of longevity for all forms of viral particles are needed for such models to be useful. We conducted a time course study to determine the viability and longevity of H1N1 virus on naturally contaminated hands and household surfaces of 20 individuals with laboratory-confirmed infection. Participants coughed or sneezed into their hands, which were sampled immediately and again after 5, 10, and 30 minutes. Samples also were obtained from household surfaces handled by the participants immediately after coughing/sneezing. Clinically obtained H1N1 isolates were used to assess the viability and longevity of the virus on various artificially inoculated common household surfaces and human hands in a controlled laboratory setting. Viral detection was achieved by culture and real-time reverse-transcriptase polymerase chain reaction. The results suggest that H1N1 does not survive long on naturally contaminated skin and fomites, and that secretions deposited on hands by coughing or sneezing have a concentration of <2.15 × 10 to 2.94 × 10 TCID(50)/mL. These data can be used to estimate the relative contribution of direct and indirect contact transmission on overall infection rates. Copyright © 2012 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Continuous decoding of human grasp kinematics using epidural and subdural signals

NASA Astrophysics Data System (ADS)

Flint, Robert D.; Rosenow, Joshua M.; Tate, Matthew C.; Slutzky, Marc W.

2017-02-01

Objective. Restoring or replacing function in paralyzed individuals will one day be achieved through the use of brain-machine interfaces. Regaining hand function is a major goal for paralyzed patients. Two competing prerequisites for the widespread adoption of any hand neuroprosthesis are accurate control over the fine details of movement, and minimized invasiveness. Here, we explore the interplay between these two goals by comparing our ability to decode hand movements with subdural and epidural field potentials (EFPs). Approach. We measured the accuracy of decoding continuous hand and finger kinematics during naturalistic grasping motions in five human subjects. We recorded subdural surface potentials (electrocorticography; ECoG) as well as with EFPs, with both standard- and high-resolution electrode arrays. Main results. In all five subjects, decoding of continuous kinematics significantly exceeded chance, using either EGoG or EFPs. ECoG decoding accuracy compared favorably with prior investigations of grasp kinematics (mean ± SD grasp aperture variance accounted for was 0.54 ± 0.05 across all subjects, 0.75 ± 0.09 for the best subject). In general, EFP decoding performed comparably to ECoG decoding. The 7-20 Hz and 70-115 Hz spectral bands contained the most information about grasp kinematics, with the 70-115 Hz band containing greater information about more subtle movements. Higher-resolution recording arrays provided clearly superior performance compared to standard-resolution arrays. Significance. To approach the fine motor control achieved by an intact brain-body system, it will be necessary to execute motor intent on a continuous basis with high accuracy. The current results demonstrate that this level of accuracy might be achievable not just with ECoG, but with EFPs as well. Epidural placement of electrodes is less invasive, and therefore may incur less risk of encephalitis or stroke than subdural placement of electrodes. Accurately decoding motor commands at the epidural level may be an important step towards a clinically viable brain-machine interface.

Continuous decoding of human grasp kinematics using epidural and subdural signals

PubMed Central

Flint, Robert D.; Rosenow, Joshua M.; Tate, Matthew C.; Slutzky, Marc W.

2017-01-01

Objective Restoring or replacing function in paralyzed individuals will one day be achieved through the use of brain-machine interfaces (BMIs). Regaining hand function is a major goal for paralyzed patients. Two competing prerequisites for the widespread adoption of any hand neuroprosthesis are: accurate control over the fine details of movement, and minimized invasiveness. Here, we explore the interplay between these two goals by comparing our ability to decode hand movements with subdural and epidural field potentials. Approach We measured the accuracy of decoding continuous hand and finger kinematics during naturalistic grasping motions in five human subjects. We recorded subdural surface potentials (electrocorticography; ECoG) as well as with epidural field potentials (EFPs), with both standard- and high-resolution electrode arrays. Main results In all five subjects, decoding of continuous kinematics significantly exceeded chance, using either EGoG or EFPs. ECoG decoding accuracy compared favorably with prior investigations of grasp kinematics (mean± SD grasp aperture variance accounted for was 0.54± 0.05 across all subjects, 0.75± 0.09 for the best subject). In general, EFP decoding performed comparably to ECoG decoding. The 7–20 Hz and 70–115 Hz spectral bands contained the most information about grasp kinematics, with the 70–115 Hz band containing greater information about more subtle movements. Higher-resolution recording arrays provided clearly superior performance compared to standard-resolution arrays. Significance To approach the fine motor control achieved by an intact brain-body system, it will be necessary to execute motor intent on a continuous basis with high accuracy. The current results demonstrate that this level of accuracy might be achievable not just with ECoG, but with EFPs as well. Epidural placement of electrodes is less invasive, and therefore may incur less risk of encephalitis or stroke than subdural placement of electrodes. Accurately decoding motor commands at the epidural level may be an important step towards a clinically viable brain-machine interface. PMID:27900947

The role and utilisation of public health evaluations in Europe: a case study of national hand hygiene campaigns

PubMed Central

2014-01-01

Background Evaluations are essential to judge the success of public health programmes. In Europe, the proportion of public health programmes that undergo evaluation remains unclear. The European Centre for Disease Prevention and Control sought to determine the frequency of evaluations amongst European national public health programmes by using national hand hygiene campaigns as an example of intervention. Methods A cohort of all national hand hygiene campaigns initiated between 2000 and 2012 was utilised for the analysis. The aim was to collect information about evaluations of hand hygiene campaigns and their frequency. The survey was sent to nominated contact points for healthcare-associated infection surveillance in European Union and European Economic Area Member States. Results Thirty-six hand hygiene campaigns in 20 countries were performed between 2000 and 2012. Of these, 50% had undergone an evaluation and 55% of those utilised the WHO hand hygiene intervention self-assessment tool. Evaluations utilised a variety of methodologies and indicators in assessing changes in hand hygiene behaviours pre and post intervention. Of the 50% of campaigns that were not evaluated, two thirds reported that both human and financial resource constraints posed significant barriers for the evaluation. Conclusion The study identified an upward trend in the number of hand hygiene campaigns implemented in Europe. It is likely that the availability of the internationally-accepted evaluation methodology developed by the WHO contributed to the evaluation of more hand hygiene campaigns in Europe. Despite this rise, hand hygiene campaigns appear to be under-evaluated. The development of simple, programme-specific, standardised guidelines, evaluation indicators and other evidence-based public health materials could help promote evaluations across all areas of public health. PMID:24507086

A big data approach to the concordance of the toxicity of pharmaceuticals in animals and humans.

PubMed

Clark, Matthew; Steger-Hartmann, Thomas

2018-07-01

Although lack of efficacy is an important cause of late stage attrition in drug development the shortcomings in the translation of toxicities observed during the preclinical development to observations in clinical trials or post-approval is an ongoing topic of research. The concordance between preclinical and clinical safety observations has been analyzed only on relatively small data sets, mostly over short time periods of drug approvals. We therefore explored the feasibility of a big-data analysis on a set of 3,290 approved drugs and formulations for which 1,637,449 adverse events were reported for both humans animal species in regulatory submissions over a period of more than 70 years. The events reported in five species - rat, dog, mouse, rabbit, and cynomolgus monkey - were treated as diagnostic tests for human events and the diagnostic power was computed for each event/species pair using likelihood ratios. The animal-human translation of many key observations is confirmed as being predictive, such as QT prolongation and arrhythmias in dog. Our study confirmed the general predictivity of animal safety observations for humans, but also identified issues of such automated analyses which are on the one hand related to data curation and controlled vocabularies, on the other hand to methodological changes over the course of time. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Evaluation of Pressure Capacitive Sensors for Application in Grasping and Manipulation Analysis.

PubMed

Pessia, Paola; Cordella, Francesca; Schena, Emiliano; Davalli, Angelo; Sacchetti, Rinaldo; Zollo, Loredana

2017-12-08

The analysis of the human grasping and manipulation capabilities is paramount for investigating human sensory-motor control and developing prosthetic and robotic hands resembling the human ones. A viable solution to perform this analysis is to develop instrumented objects measuring the interaction forces with the hand. In this context, the performance of the sensors embedded in the objects is crucial. This paper focuses on the experimental characterization of a class of capacitive pressure sensors suitable for biomechanical analysis. The analysis was performed in three loading conditions (Distributed load, 9 Tips load, and Wave-shaped load, thanks to three different inter-elements) via a traction/compression testing machine. Sensor assessment was also carried out under human- like grasping condition by placing a silicon material with the same properties of prosthetic cosmetic gloves in between the sensor and the inter-element in order to simulate the human skin. Data show that the input-output relationship of the analyzed, sensor is strongly influenced by both the loading condition (i.e., type of inter-element) and the grasping condition (with or without the silicon material). This needs to be taken into account to avoid significant measurement error. To go over this hurdle, the sensors have to be calibrated under each specific condition in order to apply suitable corrections to the sensor output and significantly improve the measurement accuracy.

Evaluation of Pressure Capacitive Sensors for Application in Grasping and Manipulation Analysis

PubMed Central

Pessia, Paola; Cordella, Francesca; Davalli, Angelo; Sacchetti, Rinaldo; Zollo, Loredana

2017-01-01

The analysis of the human grasping and manipulation capabilities is paramount for investigating human sensory-motor control and developing prosthetic and robotic hands resembling the human ones. A viable solution to perform this analysis is to develop instrumented objects measuring the interaction forces with the hand. In this context, the performance of the sensors embedded in the objects is crucial. This paper focuses on the experimental characterization of a class of capacitive pressure sensors suitable for biomechanical analysis. The analysis was performed in three loading conditions (Distributed load, 9 Tips load, and Wave-shaped load, thanks to three different inter-elements) via a traction/compression testing machine. Sensor assessment was also carried out under human- like grasping condition by placing a silicon material with the same properties of prosthetic cosmetic gloves in between the sensor and the inter-element in order to simulate the human skin. Data show that the input–output relationship of the analyzed, sensor is strongly influenced by both the loading condition (i.e., type of inter-element) and the grasping condition (with or without the silicon material). This needs to be taken into account to avoid significant measurement error. To go over this hurdle, the sensors have to be calibrated under each specific condition in order to apply suitable corrections to the sensor output and significantly improve the measurement accuracy. PMID:29292717

Single cell qPCR reveals that additional HAND2 and microRNA-1 facilitate the early reprogramming progress of seven-factor-induced human myocytes

PubMed Central

Bektik, Emre; Dennis, Adrienne; Prasanna, Prateek; Madabhushi, Anant

2017-01-01

The direct reprogramming of cardiac fibroblasts into induced cardiomyocyte (CM)-like cells (iCMs) holds great promise in restoring heart function. We previously found that human fibroblasts could be reprogrammed toward CM-like cells by 7 reprogramming factors; however, iCM reprogramming in human fibroblasts is both more difficult and more time-intensive than that in mouse cells. In this study, we investigated if additional reprogramming factors could quantitatively and/or qualitatively improve 7-factor-mediated human iCM reprogramming by single-cell quantitative PCR. We first validated 46 pairs of TaqMan® primers/probes that had sufficient efficiency and sensitivity to detect the significant difference of gene expression between individual H9 human embryonic stem cell (ESC)-differentiated CMs (H9CMs) and human fibroblasts. The expression profile of these 46 genes revealed an improved reprogramming in 12-week iCMs compared to 4-week iCMs reprogrammed by 7 factors, indicating a prolonged stochastic phase during human iCM reprogramming. Although none of additional one reprogramming factor yielded a greater number of iCMs, our single-cell qPCR revealed that additional HAND2 or microRNA-1 could facilitate the silencing of fibroblast genes and yield a better degree of reprogramming in more reprogrammed iCMs. Noticeably, the more HAND2 expressed, the higher-level were cardiac genes activated in 7Fs+HAND2-reprogrammed iCMs. In conclusion, HAND2 and microRNA-1 could help 7 factors to facilitate the early progress of iCM-reprogramming from human fibroblasts. Our study provides valuable information to further optimize a method of direct iCM-reprogramming in human cells. PMID:28796841

Single cell qPCR reveals that additional HAND2 and microRNA-1 facilitate the early reprogramming progress of seven-factor-induced human myocytes.

PubMed

Bektik, Emre; Dennis, Adrienne; Prasanna, Prateek; Madabhushi, Anant; Fu, Ji-Dong

2017-01-01

The direct reprogramming of cardiac fibroblasts into induced cardiomyocyte (CM)-like cells (iCMs) holds great promise in restoring heart function. We previously found that human fibroblasts could be reprogrammed toward CM-like cells by 7 reprogramming factors; however, iCM reprogramming in human fibroblasts is both more difficult and more time-intensive than that in mouse cells. In this study, we investigated if additional reprogramming factors could quantitatively and/or qualitatively improve 7-factor-mediated human iCM reprogramming by single-cell quantitative PCR. We first validated 46 pairs of TaqMan® primers/probes that had sufficient efficiency and sensitivity to detect the significant difference of gene expression between individual H9 human embryonic stem cell (ESC)-differentiated CMs (H9CMs) and human fibroblasts. The expression profile of these 46 genes revealed an improved reprogramming in 12-week iCMs compared to 4-week iCMs reprogrammed by 7 factors, indicating a prolonged stochastic phase during human iCM reprogramming. Although none of additional one reprogramming factor yielded a greater number of iCMs, our single-cell qPCR revealed that additional HAND2 or microRNA-1 could facilitate the silencing of fibroblast genes and yield a better degree of reprogramming in more reprogrammed iCMs. Noticeably, the more HAND2 expressed, the higher-level were cardiac genes activated in 7Fs+HAND2-reprogrammed iCMs. In conclusion, HAND2 and microRNA-1 could help 7 factors to facilitate the early progress of iCM-reprogramming from human fibroblasts. Our study provides valuable information to further optimize a method of direct iCM-reprogramming in human cells.

[Infection control and hand hygiene in nursing homes in Oslo].

PubMed

Sie, Ingrid; Thorstad, Margrete; Andersen, Bjørg Marit

2008-06-26

Nosocomial infections and transmission can be substantially reduced by good infection control. The laws and regulations for infection control in heath care institutions emphasize establishment of infection control programs and improved hand hygiene. Our study reviews some factors that are important for practicing adequate hand hygiene (knowledge about infection control and hand-washing facilities). Health care workers (HCW) in nursing homes in Oslo participated in this study in 2006-2007. A questionnaire was made and SPSS was used to analyse the data . 70.7% of 324 HCW (in 42 nursing homes) answered the questionnaires. Nearly all of the respondents (95.6%) knew about the written procedures for hygiene and infection control; 88.5% knew that an infection control program was in place and about 50% had received information through internal education. Three of four had read the National guidelines for hand hygiene, 77.5% thought that hand disinfection was more effective than hand washing, and 97% reported hand hygiene after contact with a patient having an infection. Dispensers for hand disinfection were situated at central work places. At the same time, 17.9% informed that they worked in more than one place at the same time. This study confirms that most nursing homes in Oslo have an infection control program and training that improves the knowledge and awareness of hand hygiene among HCWs. However, the fact that nursing homes in Oslo have the resources, knowledge and education, is not the same as compliance.

SeleCon: Scalable IoT Device Selection and Control Using Hand Gestures.

PubMed

Alanwar, Amr; Alzantot, Moustafa; Ho, Bo-Jhang; Martin, Paul; Srivastava, Mani

2017-04-01

Although different interaction modalities have been proposed in the field of human-computer interface (HCI), only a few of these techniques could reach the end users because of scalability and usability issues. Given the popularity and the growing number of IoT devices, selecting one out of many devices becomes a hurdle in a typical smarthome environment. Therefore, an easy-to-learn, scalable, and non-intrusive interaction modality has to be explored. In this paper, we propose a pointing approach to interact with devices, as pointing is arguably a natural way for device selection. We introduce SeleCon for device selection and control which uses an ultra-wideband (UWB) equipped smartwatch. To interact with a device in our system, people can point to the device to select it then draw a hand gesture in the air to specify a control action. To this end, SeleCon employs inertial sensors for pointing gesture detection and a UWB transceiver for identifying the selected device from ranging measurements. Furthermore, SeleCon supports an alphabet of gestures that can be used for controlling the selected devices. We performed our experiment in a 9 m -by-10 m lab space with eight deployed devices. The results demonstrate that SeleCon can achieve 84.5% accuracy for device selection and 97% accuracy for hand gesture recognition. We also show that SeleCon is power efficient to sustain daily use by turning off the UWB transceiver, when a user's wrist is stationary.

SeleCon: Scalable IoT Device Selection and Control Using Hand Gestures

PubMed Central

Alanwar, Amr; Alzantot, Moustafa; Ho, Bo-Jhang; Martin, Paul; Srivastava, Mani

2018-01-01

Although different interaction modalities have been proposed in the field of human-computer interface (HCI), only a few of these techniques could reach the end users because of scalability and usability issues. Given the popularity and the growing number of IoT devices, selecting one out of many devices becomes a hurdle in a typical smarthome environment. Therefore, an easy-to-learn, scalable, and non-intrusive interaction modality has to be explored. In this paper, we propose a pointing approach to interact with devices, as pointing is arguably a natural way for device selection. We introduce SeleCon for device selection and control which uses an ultra-wideband (UWB) equipped smartwatch. To interact with a device in our system, people can point to the device to select it then draw a hand gesture in the air to specify a control action. To this end, SeleCon employs inertial sensors for pointing gesture detection and a UWB transceiver for identifying the selected device from ranging measurements. Furthermore, SeleCon supports an alphabet of gestures that can be used for controlling the selected devices. We performed our experiment in a 9m-by-10m lab space with eight deployed devices. The results demonstrate that SeleCon can achieve 84.5% accuracy for device selection and 97% accuracy for hand gesture recognition. We also show that SeleCon is power efficient to sustain daily use by turning off the UWB transceiver, when a user’s wrist is stationary. PMID:29683151

The 3D Human Motion Control Through Refined Video Gesture Annotation

NASA Astrophysics Data System (ADS)

Jin, Yohan; Suk, Myunghoon; Prabhakaran, B.

In the beginning of computer and video game industry, simple game controllers consisting of buttons and joysticks were employed, but recently game consoles are replacing joystick buttons with novel interfaces such as the remote controllers with motion sensing technology on the Nintendo Wii [1] Especially video-based human computer interaction (HCI) technique has been applied to games, and the representative game is 'Eyetoy' on the Sony PlayStation 2. Video-based HCI technique has great benefit to release players from the intractable game controller. Moreover, in order to communicate between humans and computers, video-based HCI is very crucial since it is intuitive, easy to get, and inexpensive. On the one hand, extracting semantic low-level features from video human motion data is still a major challenge. The level of accuracy is really dependent on each subject's characteristic and environmental noises. Of late, people have been using 3D motion-capture data for visualizing real human motions in 3D space (e.g, 'Tiger Woods' in EA Sports, 'Angelina Jolie' in Bear-Wolf movie) and analyzing motions for specific performance (e.g, 'golf swing' and 'walking'). 3D motion-capture system ('VICON') generates a matrix for each motion clip. Here, a column is corresponding to a human's sub-body part and row represents time frames of data capture. Thus, we can extract sub-body part's motion only by selecting specific columns. Different from low-level feature values of video human motion, 3D human motion-capture data matrix are not pixel values, but is closer to human level of semantics.

Effort, success, and nonuse determine arm choice

PubMed Central

Xiao, Yupeng; Kim, Sujin; Yoshioka, Toshinori; Gordon, James; Osu, Rieko

2015-01-01

How do humans choose one arm or the other to reach single targets in front of the body? Current theories of reward-driven decisionmaking predict that choice results from a comparison of “action values,” which are the expected rewards for possible actions in a given state. In addition, current theories of motor control predict that in planning arm movements, humans minimize an expected motor cost that balances motor effort and endpoint accuracy. Here, we test the hypotheses that arm choice is determined by comparison of action values comprising expected effort and expected task success for each arm, as well as a handedness bias. Right-handed subjects, in either a large or small target condition, were first instructed to use each hand in turn to shoot through an array of targets and then to choose either hand to shoot through the same targets. Effort was estimated via inverse kinematics and dynamics. A mixed-effects logistic-regression analysis showed that, as predicted, both expected effort and expected success predicted choice, as did arm use in the preceding trial. Finally, individual parameter estimation showed that the handedness bias correlated with mean difference between right- and left-arm success, leading to overall lower use of the left arm. We discuss our results in light of arm nonuse in individuals' poststroke. PMID:25948869

Eye-hand preference in schizophrenia: sex differences and significance for hand function.

PubMed

Liu, Yi-Chia; Yang, Yen Kuang; Lee, I Hui; Lin, Keh-Chung; Jeffries, Keith J; Lee, Li-Ching

2004-06-01

Hand preference and eye dominance were investigated in 73 (30 women, 43 men) schizophrenic patients and 71 (30 women, 41 men) healthy controls. There were significantly more schizophrenic patients and normal controls who were significantly right-hand dominant. However, schizophrenic patients showed a significant excess of left-eye dominance relative to controls (65.8% vs 29.6%; Odds Ratio= 4.75, p< .001). In addition, female schizophrenic patients showed a higher rate of nonright (either left or inconsistent) eye dominance (80%) than male schizophrenic patients (55.8%) and controls (33.3%). Analysis of hand performance on the Purdue Pegboard Test indicated that schizophrenic patients who showed crossed eye-hand dominance scored higher than did patients without crossed eye-hand dominance.

Real-time face and gesture analysis for human-robot interaction

NASA Astrophysics Data System (ADS)

Wallhoff, Frank; Rehrl, Tobias; Mayer, Christoph; Radig, Bernd

2010-05-01

Human communication relies on a large number of different communication mechanisms like spoken language, facial expressions, or gestures. Facial expressions and gestures are one of the main nonverbal communication mechanisms and pass large amounts of information between human dialog partners. Therefore, to allow for intuitive human-machine interaction, a real-time capable processing and recognition of facial expressions, hand and head gestures are of great importance. We present a system that is tackling these challenges. The input features for the dynamic head gestures and facial expressions are obtained from a sophisticated three-dimensional model, which is fitted to the user in a real-time capable manner. Applying this model different kinds of information are extracted from the image data and afterwards handed over to a real-time capable data-transferring framework, the so-called Real-Time DataBase (RTDB). In addition to the head and facial-related features, also low-level image features regarding the human hand - optical flow, Hu-moments are stored into the RTDB for the evaluation process of hand gestures. In general, the input of a single camera is sufficient for the parallel evaluation of the different gestures and facial expressions. The real-time capable recognition of the dynamic hand and head gestures are performed via different Hidden Markov Models, which have proven to be a quick and real-time capable classification method. On the other hand, for the facial expressions classical decision trees or more sophisticated support vector machines are used for the classification process. These obtained results of the classification processes are again handed over to the RTDB, where other processes (like a Dialog Management Unit) can easily access them without any blocking effects. In addition, an adjustable amount of history can be stored by the RTDB buffer unit.

Measuring empathy for human and robot hand pain using electroencephalography.

PubMed

Suzuki, Yutaka; Galli, Lisa; Ikeda, Ayaka; Itakura, Shoji; Kitazaki, Michiteru

2015-11-03

This study provides the first physiological evidence of humans' ability to empathize with robot pain and highlights the difference in empathy for humans and robots. We performed electroencephalography in 15 healthy adults who observed either human- or robot-hand pictures in painful or non-painful situations such as a finger cut by a knife. We found that the descending phase of the P3 component was larger for the painful stimuli than the non-painful stimuli, regardless of whether the hand belonged to a human or robot. In contrast, the ascending phase of the P3 component at the frontal-central electrodes was increased by painful human stimuli but not painful robot stimuli, though the interaction of ANOVA was not significant, but marginal. These results suggest that we empathize with humanoid robots in late top-down processing similarly to human others. However, the beginning of the top-down process of empathy is weaker for robots than for humans.

Agile development of ontologies through conversation

NASA Astrophysics Data System (ADS)

Braines, Dave; Bhattal, Amardeep; Preece, Alun D.; de Mel, Geeth

2016-05-01

Ontologies and semantic systems are necessarily complex but offer great potential in terms of their ability to fuse information from multiple sources in support of situation awareness. Current approaches do not place the ontologies directly into the hands of the end user in the field but instead hide them away behind traditional applications. We have been experimenting with human-friendly ontologies and conversational interactions to enable non-technical business users to interact with and extend these dynamically. In this paper we outline our approach via a worked example, covering: OWL ontologies, ITA Controlled English, Sensor/mission matching and conversational interactions between human and machine agents.

Acoustothermometric study of the human hand under hyperthrmia and hypothermia

NASA Astrophysics Data System (ADS)

Anosov, A. A.; Belyaev, R. V.; Vilkov, V. A.; Dvornikova, M. V.; Dvornikova, V. V.; Kazanskii, A. S.; Kuryatnikova, N. A.; Mansfel'd, A. D.

2013-01-01

The results of an acoustothermometric study of the human hand under local hyperthermia and hypothermia are presented. Individuals under testing plunged their hands in hot or cold water for several minutes. Thermal acoustic radiation was detected by two sensors placed near the palm and near the backside of the tested hand. The internal temperature profiles of the hand were reconstructed. The indirect estimate of the reconstruction error was 0.6°C, which is acceptable for medical applications. Hyperthermia was achieved by placing the hand in water with a maximal temperature of 44°C for 2 min. In this case, the internal temperature was 35.4 ± 0.6°C. Hypothermia was achieved by placing the hand in water with a temperature of 17.8°C for 15 min. In this case, the internal temperature decreased from 26 to 24°C. The use of a four-sensor planar receiving array allowed dynamic mapping of the acoustic brightness temperature of the hand.

Smart Prosthetic Hand Technology - Phase 2

DTIC Science & Technology

2011-05-01

identification and estimation, hand motion estimation, intelligent embedded systems and control, robotic hand and biocompatibility and signaling. The...Smart Prosthetics, Bio- Robotics , Intelligent EMG Signal Processing, Embedded Systems and Intelligent Control, Inflammatory Responses of Cells, Toxicity...estimation, intelligent embedded systems and control, robotic hand and biocompatibility and signaling. The developed identification algorithm using a new

Electromyography data for non-invasive naturally-controlled robotic hand prostheses

PubMed Central

Atzori, Manfredo; Gijsberts, Arjan; Castellini, Claudio; Caputo, Barbara; Hager, Anne-Gabrielle Mittaz; Elsig, Simone; Giatsidis, Giorgio; Bassetto, Franco; Müller, Henning

2014-01-01

Recent advances in rehabilitation robotics suggest that it may be possible for hand-amputated subjects to recover at least a significant part of the lost hand functionality. The control of robotic prosthetic hands using non-invasive techniques is still a challenge in real life: myoelectric prostheses give limited control capabilities, the control is often unnatural and must be learned through long training times. Meanwhile, scientific literature results are promising but they are still far from fulfilling real-life needs. This work aims to close this gap by allowing worldwide research groups to develop and test movement recognition and force control algorithms on a benchmark scientific database. The database is targeted at studying the relationship between surface electromyography, hand kinematics and hand forces, with the final goal of developing non-invasive, naturally controlled, robotic hand prostheses. The validation section verifies that the data are similar to data acquired in real-life conditions, and that recognition of different hand tasks by applying state-of-the-art signal features and machine-learning algorithms is possible. PMID:25977804

Application of dexterous space robotics technology to myoelectric prostheses

NASA Astrophysics Data System (ADS)

Hess, Clifford; Li, Larry C. H.; Farry, Kristin A.; Walker, Ian D.

1994-02-01

Future space missions will require robots equipped with highly dexterous robotic hands to perform a variety of tasks. A major technical challenge in making this possible is an improvement in the way these dexterous robotic hands are remotely controlled or teleoperated. NASA is currently investigating the feasibility of using myoelectric signals to teleoperate a dexterous robotic hand. In theory, myoelectric control of robotic hands will require little or no mechanical parts and will greatly reduce the bulk and weight usually found in dexterous robotic hand control devices. An improvement in myoelectric control of multifinger hands will also benefit prosthetics users. Therefore, as an effort to transfer dexterous space robotics technology to prosthetics applications and to benefit from existing myoelectric technology, NASA is collaborating with the Limbs of Love Foundation, the Institute for Rehabilitation and Research, and Rice University in developing improved myoelectric control multifinger hands and prostheses. In this paper, we will address the objectives and approaches of this collaborative effort and discuss the technical issues associated with myoelectric control of multifinger hands. We will also report our current progress and discuss plans for future work.

Application of dexterous space robotics technology to myoelectric prostheses

NASA Technical Reports Server (NTRS)

Hess, Clifford; Li, Larry C. H.; Farry, Kristin A.; Walker, Ian D.

1994-01-01

Future space missions will require robots equipped with highly dexterous robotic hands to perform a variety of tasks. A major technical challenge in making this possible is an improvement in the way these dexterous robotic hands are remotely controlled or teleoperated. NASA is currently investigating the feasibility of using myoelectric signals to teleoperate a dexterous robotic hand. In theory, myoelectric control of robotic hands will require little or no mechanical parts and will greatly reduce the bulk and weight usually found in dexterous robotic hand control devices. An improvement in myoelectric control of multifinger hands will also benefit prosthetics users. Therefore, as an effort to transfer dexterous space robotics technology to prosthetics applications and to benefit from existing myoelectric technology, NASA is collaborating with the Limbs of Love Foundation, the Institute for Rehabilitation and Research, and Rice University in developing improved myoelectric control multifinger hands and prostheses. In this paper, we will address the objectives and approaches of this collaborative effort and discuss the technical issues associated with myoelectric control of multifinger hands. We will also report our current progress and discuss plans for future work.

Alternative splicing: the pledge, the turn, and the prestige : The key role of alternative splicing in human biological systems.

PubMed

Gallego-Paez, L M; Bordone, M C; Leote, A C; Saraiva-Agostinho, N; Ascensão-Ferreira, M; Barbosa-Morais, N L

2017-09-01

Alternative pre-mRNA splicing is a tightly controlled process conducted by the spliceosome, with the assistance of several regulators, resulting in the expression of different transcript isoforms from the same gene and increasing both transcriptome and proteome complexity. The differences between alternative isoforms may be subtle but enough to change the function or localization of the translated proteins. A fine control of the isoform balance is, therefore, needed throughout developmental stages and adult tissues or physiological conditions and it does not come as a surprise that several diseases are caused by its deregulation. In this review, we aim to bring the splicing machinery on stage and raise the curtain on its mechanisms and regulation throughout several systems and tissues of the human body, from neurodevelopment to the interactions with the human microbiome. We discuss, on one hand, the essential role of alternative splicing in assuring tissue function, diversity, and swiftness of response in these systems or tissues, and on the other hand, what goes wrong when its regulatory mechanisms fail. We also focus on the possibilities that splicing modulation therapies open for the future of personalized medicine, along with the leading techniques in this field. The final act of the spliceosome, however, is yet to be fully revealed, as more knowledge is needed regarding the complex regulatory network that coordinates alternative splicing and how its dysfunction leads to disease.

Recent progress in econophysics: Chaos, leverage, and business cycles as revealed by agent-based modeling and human experiments

NASA Astrophysics Data System (ADS)

Xin, Chen; Huang, Ji-Ping

2017-12-01

Agent-based modeling and controlled human experiments serve as two fundamental research methods in the field of econophysics. Agent-based modeling has been in development for over 20 years, but how to design virtual agents with high levels of human-like "intelligence" remains a challenge. On the other hand, experimental econophysics is an emerging field; however, there is a lack of experience and paradigms related to the field. Here, we review some of the most recent research results obtained through the use of these two methods concerning financial problems such as chaos, leverage, and business cycles. We also review the principles behind assessments of agents' intelligence levels, and some relevant designs for human experiments. The main theme of this review is to show that by combining theory, agent-based modeling, and controlled human experiments, one can garner more reliable and credible results on account of a better verification of theory; accordingly, this way, a wider range of economic and financial problems and phenomena can be studied.

A synergy-driven approach to a myoelectric hand.

PubMed

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.

Trends in Immigration of Selected High-Skilled Immigrants to the U.S. from 1997 to 2006

ERIC Educational Resources Information Center

Zhou, Fan

2009-01-01

One result of accelerating globalization is the competition for human capital. On one hand, nations are investing more and more in their educational systems to create their own human resources; on the other hand, these nations are struggling to effectively and efficiently utilize their existing human capital. Additionally, there is a massive wave…

Bilateral transfer for learning to control timing but not for learning to control fine force.

PubMed

Yao, Wan X; Cordova, Alberto; Huang, Yufei; Wang, Yan; Lu, Xing

2014-04-01

This study examined the characteristics of bilateral transfer of learning to control timing and fine force from a dominant limb to a nondominant limb. 20 right-handed college students (12 women, 8 men; M age = 21.5 yr., SD = 2.3) learned a sequential task consisting of timing and force control. Each participant completed a pre-test of the task with both hands and then performed 100 practice trials with the dominant hand. A post-test was conducted 1 hr. later. The results showed that after training, participants learned to control the timing and force. Nevertheless, only the time-control learning was transferred to the untrained hand, whereas the force-control learning did not transfer to the untrained hand.

Bimanual Force Variability and Chronic Stroke: Asymmetrical Hand Control

PubMed Central

Kang, Nyeonju; Cauraugh, James H.

2014-01-01

The purpose of this study was to investigate force variability generated by both the paretic and non-paretic hands during bimanual force control. Nine chronic stroke individuals and nine age-matched individuals with no stroke history performed a force control task with both hands simultaneously. The task involved extending the wrist and fingers at 5%, 25%, and 50% of maximum voluntary contraction. Bimanual and unimanual force variability during bimanual force control was determined by calculating the coefficient of variation. Analyses revealed two main findings: (a) greater bimanual force variability in the stroke group than the control group and (b) increased force variability by the paretic hands during bimanual force control in comparison to the non-paretic hands at the 5% and 25% force production conditions. A primary conclusion is that post stroke bimanual force variability is asymmetrical between hands. PMID:25000185

TROTER's (Tiny Robotic Operation Team Experiment): A new concept of space robots

NASA Technical Reports Server (NTRS)

Su, Renjeng

1990-01-01

In view of the future need of automation and robotics in space and the existing approaches to the problem, we proposed a new concept of robots for space construction. The new concept is based on the basic idea of decentralization. Decentralization occurs, on the one hand, in using teams of many cooperative robots for construction tasks. Redundancy and modular design are explored to achieve high reliability for team robotic operations. Reliability requirement on individual robots is greatly reduced. Another area of decentralization is manifested by the proposed control hierarchy which eventually includes humans in the loop. The control strategy is constrained by various time delays and calls for different levels of abstraction of the task dynamics. Such technology is needed for remote control of robots in an uncertain environment. Thus, concerns of human safety around robots are relaxed. This presentation also introduces the required technologies behind the new robotic concept.

Target switching in curved human arm movements is predicted by changing a single control parameter.

PubMed

Hoffmann, Heiko

2011-01-01

Straight-line movements have been studied extensively in the human motor-control literature, but little is known about how to generate curved movements and how to adjust them in a dynamic environment. The present work studied, for the first time to my knowledge, how humans adjust curved hand movements to a target that switches location. Subjects (n = 8) sat in front of a drawing tablet and looked at a screen. They moved a cursor on a curved trajectory (spiral or oval shaped) toward a goal point. In half of the trials, this goal switched 200 ms after movement onset to either one of two alternative positions, and subjects smoothly adjusted their movements to the new goal. To explain this adjustment, we compared three computational models: a superposition of curved and minimum-jerk movements (Flash and Henis in J Cogn Neurosci 3(3):220-230, 1991), Vector Planning (Gordon et al. in Exp Brain Res 99(1):97-111, 1994) adapted to curved movements (Rescale), and a nonlinear dynamical system, which could generate arbitrarily curved smooth movements and had a point attractor at the goal. For each model, we predicted the trajectory adjustment to the target switch by changing only the goal position in the model. As result, the dynamical model could explain the observed switch behavior significantly better than the two alternative models (spiral: P = 0.0002 vs. Flash, P = 0.002 vs. Rescale; oval: P = 0.04 vs. Flash; P values obtained from Wilcoxon test on R (2) values). We conclude that generalizing arbitrary hand trajectories to new targets may be explained by switching a single control command, without the need to re-plan or re-optimize the whole movement or superimpose movements.

Repeated Structural Imaging Reveals Nonlinear Progression of Experience-Dependent Volume Changes in Human Motor Cortex.

PubMed

Wenger, Elisabeth; Kühn, Simone; Verrel, Julius; Mårtensson, Johan; Bodammer, Nils Christian; Lindenberger, Ulman; Lövdén, Martin

2017-05-01

Evidence for experience-dependent structural brain change in adult humans is accumulating. However, its time course is not well understood, as intervention studies typically consist of only 2 imaging sessions (before vs. after training). We acquired up to 18 structural magnetic resonance images over a 7-week period while 15 right-handed participants practiced left-hand writing and drawing. After 4 weeks, we observed increases in gray matter of both left and right primary motor cortices relative to a control group; 3 weeks later, these differences were no longer reliable. Time-series analyses revealed that gray matter in the primary motor cortices expanded during the first 4 weeks and then partially renormalized, in particular in the right hemisphere, despite continued practice and increasing task proficiency. Similar patterns of expansion followed by partial renormalization are also found in synaptogenesis, cortical map plasticity, and maturation, and may qualify as a general principle of structural plasticity. Research on human brain plasticity needs to encompass more than 2 measurement occasions to capture expansion and potential renormalization processes over time. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A human factors evaluation of Extravehicular Activity gloves

NASA Technical Reports Server (NTRS)

O'Hara, John M.; Briganti, Michael; Cleland, John; Winfield, Dan

1989-01-01

One of the major problems faced in Extravehicular Activity (EVA) glove development has been the absence of concise and reliable methods to measure the effects of EVA gloves on human-hand capabilities. NASA has sponsored a program to develop a standardized set of tests designed to assess EVA-gloved hand capabilities in six performance domains: Range of Motion, Strength, Tactile Perception, Dexterity, Fatigue, and Comfort. Based upon an assessment of general human-hand functioning and EVA task requirements, several tests within each performance domain were developed to provide a comprehensive evaluation. All tests were designed to be conducted in a glove box with the bare hand, an EVA glove without pressure, an EVA glove at operation pressure. Thus, the differential effect on performance of the glove with and without pressure was tested. Bare hand performance was used to 'calibrate' the effects. Ten subjects participated in the test setup as a repeated-measures experimental design. The paper will report the results of the test program.

Hand gesture recognition in confined spaces with partial observability and occultation constraints

NASA Astrophysics Data System (ADS)

Shirkhodaie, Amir; Chan, Alex; Hu, Shuowen

2016-05-01

Human activity detection and recognition capabilities have broad applications for military and homeland security. These tasks are very complicated, however, especially when multiple persons are performing concurrent activities in confined spaces that impose significant obstruction, occultation, and observability uncertainty. In this paper, our primary contribution is to present a dedicated taxonomy and kinematic ontology that are developed for in-vehicle group human activities (IVGA). Secondly, we describe a set of hand-observable patterns that represents certain IVGA examples. Thirdly, we propose two classifiers for hand gesture recognition and compare their performance individually and jointly. Finally, we present a variant of Hidden Markov Model for Bayesian tracking, recognition, and annotation of hand motions, which enables spatiotemporal inference to human group activity perception and understanding. To validate our approach, synthetic (graphical data from virtual environment) and real physical environment video imagery are employed to verify the performance of these hand gesture classifiers, while measuring their efficiency and effectiveness based on the proposed Hidden Markov Model for tracking and interpreting dynamic spatiotemporal IVGA scenarios.

Energy stress-induced lncRNA HAND2-AS1 represses HIF1α-mediated energy metabolism and inhibits osteosarcoma progression

PubMed Central

Kang, Yao; Zhu, Xiaojun; Xu, Yanyang; Tang, Qinglian; Huang, Zongwen; Zhao, Zhiqiang; Lu, Jinchang; Song, Guohui; Xu, Huaiyuan; Deng, Chuangzhong; Wang, Jin

2018-01-01

During recent years, long noncoding RNAs (lncRNAs) have been recognized as key regulators in the development and progression of human cancers, however, their roles in osteosarcoma metabolism are still not well understood. The present study aims to investigate the expression profiles and potential modulation of specific lncRNA(s) in osteosarcoma metabolism. The high-throughput Hiseq sequencing was performed to screen for abnormally expressed lncRNAs in osteosarcoma cells cultured under glucose starvation condition, and lncRNA HAND2-AS1 was eventually identified as one that was significantly up-regulated when compared with normal cultured cells. Mechanistic investigations indicated that knockdown of HAND2-AS1 abrogated the energy stress-induced effect on cell apoptosis and proliferation, and promoted osteosarcoma progression. Moreover, knockdown of HAND2-AS1 promoted glucose uptake, lactate production, and the expression level of a serious of enzymes that involved in energy metabolism. Subsequently, RNA pull-down and RNA immuneprecipitation revealed that, upon energy stress, HAND2-AS1 regulated osteosarcoma metabolism through sequestering FBP1 from binding to HIF1α, thereby releasing HIF1α expression and promoting the protein level. Taken together, our integrated approach reveals a regulatory mechanism by lncRNA HAND2-AS1 to control energy metabolism and tumor development in osteosarcoma. Thus, HAND2-AS1 may be a potential biomarker and therapeutic target for the repression of osteosarcoma metabolism. PMID:29637006

Kind enough to care, clever enough to cope.

PubMed

Nazarko, Linda

In my lifetime the human race has reached out to the stars and walked on the surface of the moon. Now I can hold a computer more powerful than the one used to control the moon landing in the palm of my hand. Diseases that once signalled death have been reduced to the status of long-term conditions, the number of people aged 85 and over has more than tripled.

Using Simulation Speeds to Differentiate Controller Interface Concepts

NASA Technical Reports Server (NTRS)

Trujillo, Anna; Pope, Alan

2008-01-01

This study investigated two concepts: (1) whether speeding a human-in-the-loop simulation (or the subject's "world") scales time stress in such a way as to cause primary task performance to reveal workload differences between experimental conditions and (2) whether using natural hand motions to control the attitude of an aircraft makes controlling the aircraft easier and more intuitive. This was accomplished by having pilots and non-pilots make altitude and heading changes using three different control inceptors at three simulation speeds. Results indicate that simulation speed does affect workload and controllability. The bank and pitch angle error was affected by simulation speed but not by a simulation speed by controller type interaction; this may have been due to the relatively easy flying task. Results also indicate that pilots could control the bank and pitch angle of an aircraft about equally as well with the glove as with the sidestick. Non-pilots approached the pilots ability to control the bank and pitch angle of an aircraft using the positional glove - where the hand angle is directly proportional to the commanded aircraft angle. Therefore, (1) changing the simulation speed lends itself to objectively indexing a subject s workload and may also aid in differentiating among interface concepts based upon performance if the task being studied is sufficiently challenging and (2) using natural body movements to mimic the movement of an airplane for attitude control is feasible.

Operator dynamics for stability condition in haptic and teleoperation system: A survey.

PubMed

Li, Hongbing; Zhang, Lei; Kawashima, Kenji

2018-04-01

Currently, haptic systems ignore the varying impedance of the human hand with its countless configurations and thus cannot recreate the complex haptic interactions. The literature does not reveal a comprehensive survey on the methods proposed and this study is an attempt to bridge this gap. The paper includes an extensive review of human arm impedance modeling and control deployed to address inherent stability and transparency issues in haptic interaction and teleoperation systems. Detailed classification and comparative study of various contributions in human arm modeling are presented and summarized in tables and diagrams. The main challenges in modeling human arm impedance for haptic robotic applications are identified. The possible future research directions are outlined based on the gaps identified in the survey. Copyright © 2018 John Wiley & Sons, Ltd.

The myokinetic control interface: tracking implanted magnets as a means for prosthetic control.

PubMed

Tarantino, S; Clemente, F; Barone, D; Controzzi, M; Cipriani, C

2017-12-07

Upper limb amputation deprives individuals of their innate ability to manipulate objects. Such disability can be restored with a robotic prosthesis linked to the brain by a human-machine interface (HMI) capable of decoding voluntary intentions, and sending motor commands to the prosthesis. Clinical or research HMIs rely on the interpretation of electrophysiological signals recorded from the muscles. However, the quest for an HMI that allows for arbitrary and physiologically appropriate control of dexterous prostheses, is far from being completed. Here we propose a new HMI that aims to track the muscles contractions with implanted permanent magnets, by means of magnetic field sensors. We called this a myokinetic control interface. We present the concept, the features and a demonstration of a prototype which exploits six 3-axis sensors to localize four magnets implanted in a forearm mockup, for the control of a dexterous hand prosthesis. The system proved highly linear (R 2  = 0.99) and precise (1% repeatability), yet exhibiting short computation delay (45 ms) and limited cross talk errors (10% the mean stroke of the magnets). Our results open up promising possibilities for amputees, demonstrating the viability of the myokinetic approach in implementing direct and simultaneous control over multiple digits of an artificial hand.

Eye Tracking of Occluded Self-Moved Targets: Role of Haptic Feedback and Hand-Target Dynamics.

PubMed

Danion, Frederic; Mathew, James; Flanagan, J Randall

2017-01-01

Previous studies on smooth pursuit eye movements have shown that humans can continue to track the position of their hand, or a target controlled by the hand, after it is occluded, thereby demonstrating that arm motor commands contribute to the prediction of target motion driving pursuit eye movements. Here, we investigated this predictive mechanism by manipulating both the complexity of the hand-target mapping and the provision of haptic feedback. Two hand-target mappings were used, either a rigid (simple) one in which hand and target motion matched perfectly or a nonrigid (complex) one in which the target behaved as a mass attached to the hand by means of a spring. Target animation was obtained by asking participants to oscillate a lightweight robotic device that provided (or not) haptic feedback consistent with the target dynamics. Results showed that as long as 7 s after target occlusion, smooth pursuit continued to be the main contributor to total eye displacement (∼60%). However, the accuracy of eye-tracking varied substantially across experimental conditions. In general, eye-tracking was less accurate under the nonrigid mapping, as reflected by higher positional and velocity errors. Interestingly, haptic feedback helped to reduce the detrimental effects of target occlusion when participants used the nonrigid mapping, but not when they used the rigid one. Overall, we conclude that the ability to maintain smooth pursuit in the absence of visual information can extend to complex hand-target mappings, but the provision of haptic feedback is critical for the maintenance of accurate eye-tracking performance.

Eye Tracking of Occluded Self-Moved Targets: Role of Haptic Feedback and Hand-Target Dynamics

PubMed Central

Mathew, James

2017-01-01

Abstract Previous studies on smooth pursuit eye movements have shown that humans can continue to track the position of their hand, or a target controlled by the hand, after it is occluded, thereby demonstrating that arm motor commands contribute to the prediction of target motion driving pursuit eye movements. Here, we investigated this predictive mechanism by manipulating both the complexity of the hand-target mapping and the provision of haptic feedback. Two hand-target mappings were used, either a rigid (simple) one in which hand and target motion matched perfectly or a nonrigid (complex) one in which the target behaved as a mass attached to the hand by means of a spring. Target animation was obtained by asking participants to oscillate a lightweight robotic device that provided (or not) haptic feedback consistent with the target dynamics. Results showed that as long as 7 s after target occlusion, smooth pursuit continued to be the main contributor to total eye displacement (∼60%). However, the accuracy of eye-tracking varied substantially across experimental conditions. In general, eye-tracking was less accurate under the nonrigid mapping, as reflected by higher positional and velocity errors. Interestingly, haptic feedback helped to reduce the detrimental effects of target occlusion when participants used the nonrigid mapping, but not when they used the rigid one. Overall, we conclude that the ability to maintain smooth pursuit in the absence of visual information can extend to complex hand-target mappings, but the provision of haptic feedback is critical for the maintenance of accurate eye-tracking performance. PMID:28680964

[Definition of crime and judiciary procedures].

PubMed

de Graëve, Loïc

2002-04-01

The word crime takes various definitions depending on the criminal, sociological, political, or even penal viewpoint. On the one hand, it relies upon various references which can be sizeable or superficial values, individual or collective values, moral or material values, national or universal values. On the other hand, the notion of crime gathers behaviours that are considered by the entire population and the legislator as the strongest violations of the fundamental interests of the human being, of the social group and of the state-controlled institutions. Despite the multiplicity of those meanings, repression of crime comes within the framework of a precise judiciary procedure, dooming to failure any attempt at arbitrary decisions. The unfolding proceedings in the assizes courts are the most obvious demonstrations of that.

A common control signal and a ballistic stage can explain the control of coordinated eye-hand movements.

PubMed

Gopal, Atul; Murthy, Aditya

2016-06-01

Voluntary control has been extensively studied in the context of eye and hand movements made in isolation, yet little is known about the nature of control during eye-hand coordination. We probed this with a redirect task. Here subjects had to make reaching/pointing movements accompanied by coordinated eye movements but had to change their plans when the target occasionally changed its position during some trials. Using a race model framework, we found that separate effector-specific mechanisms may be recruited to control eye and hand movements when executed in isolation but when the same effectors are coordinated a unitary mechanism to control coordinated eye-hand movements is employed. Specifically, we found that performance curves were distinct for the eye and hand when these movements were executed in isolation but were comparable when they were executed together. Second, the time to switch motor plans, called the target step reaction time, was different in the eye-alone and hand-alone conditions but was similar in the coordinated condition under assumption of a ballistic stage of ∼40 ms, on average. Interestingly, the existence of this ballistic stage could predict the extent of eye-hand dissociations seen in individual subjects. Finally, when subjects were explicitly instructed to control specifically a single effector (eye or hand), redirecting one effector had a strong effect on the performance of the other effector. Taken together, these results suggest that a common control signal and a ballistic stage are recruited when coordinated eye-hand movement plans require alteration. Copyright © 2016 the American Physiological Society.

A common control signal and a ballistic stage can explain the control of coordinated eye-hand movements

PubMed Central

Gopal, Atul

2016-01-01

Voluntary control has been extensively studied in the context of eye and hand movements made in isolation, yet little is known about the nature of control during eye-hand coordination. We probed this with a redirect task. Here subjects had to make reaching/pointing movements accompanied by coordinated eye movements but had to change their plans when the target occasionally changed its position during some trials. Using a race model framework, we found that separate effector-specific mechanisms may be recruited to control eye and hand movements when executed in isolation but when the same effectors are coordinated a unitary mechanism to control coordinated eye-hand movements is employed. Specifically, we found that performance curves were distinct for the eye and hand when these movements were executed in isolation but were comparable when they were executed together. Second, the time to switch motor plans, called the target step reaction time, was different in the eye-alone and hand-alone conditions but was similar in the coordinated condition under assumption of a ballistic stage of ∼40 ms, on average. Interestingly, the existence of this ballistic stage could predict the extent of eye-hand dissociations seen in individual subjects. Finally, when subjects were explicitly instructed to control specifically a single effector (eye or hand), redirecting one effector had a strong effect on the performance of the other effector. Taken together, these results suggest that a common control signal and a ballistic stage are recruited when coordinated eye-hand movement plans require alteration. PMID:26888104

49 CFR 236.207 - Electric lock on hand-operated switch; control.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Electric lock on hand-operated switch; control... switch; control. Electric lock on hand-operated switch shall be controlled so that it cannot be unlocked until control circuits of signals governing movements over such switch have been opened. Approach or...

49 CFR 236.207 - Electric lock on hand-operated switch; control.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Electric lock on hand-operated switch; control... switch; control. Electric lock on hand-operated switch shall be controlled so that it cannot be unlocked until control circuits of signals governing movements over such switch have been opened. Approach or...

49 CFR 236.207 - Electric lock on hand-operated switch; control.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Electric lock on hand-operated switch; control... switch; control. Electric lock on hand-operated switch shall be controlled so that it cannot be unlocked until control circuits of signals governing movements over such switch have been opened. Approach or...

Promoting action control and coping planning to improve hand hygiene.

PubMed

Reyes Fernández, Benjamín; Lippke, Sonia; Knoll, Nina; Blanca Moya, Emanuel; Schwarzer, Ralf

2015-09-25

We examined a brief educational intervention addressing hand hygiene self-regulatory mechanisms, and evaluated which psychological mechanisms may lead to hand hygiene behaviours. Two hundred forty two students (mean age = 21 years, SD = 3.9) received either an experimental (n = 149) or a control condition on action control and planning (n = 93). Hand hygiene, coping planning, and action control were measured at baseline and six weeks later. By applying repeated measures ANOVA, we compared the experimental condition addressing planning to perform hand hygiene with a control condition. Additionally, working mechanisms were evaluated by means of mediation analysis. The intervention had an effect on action control, as reflected by a time by treatment interaction. The direct effect of the intervention on behaviour was, however, non-significant. Changes in action control led to changes in coping planning. These social-cognitive changes mediated the effect of intervention on behaviour, after controlling for gender, baseline behaviour, and classroom membership. In spite of the associations between the intervention and self-regulatory strategies, no direct effect was found of the intervention on behaviour. Further research on how to increase hand sanitizing, involving enviromental characteristics, is required. The intervention led only indirectly to an improvement of hand hygiene via changes in self-regulatory factors. Results indicate the importance of promoting action control and coping planning to initiate changes in hand hygienic behaviours.

The effects of different nickel-titanium instruments on dentinal microcrack formations during root canal preparation.

PubMed

Ustun, Yakup; Aslan, Tugrul; Sagsen, Burak; Kesim, Bertan

2015-01-01

The aim of the present study was to investigate the incidence of dentinal microcracks caused by different preparation techniques. 120 extracted human mandibular incisor teeth were divided into five experimental groups and one control group (n = 20): Group 1: Hand preparation with balanced force technique up to #25 K-file. Group 2: Preparation with only ProTaper F2 instrument in a reciprocating movement. Group 3: Preparation with Reciproc R25 instrument in a reciprocating movement. Group 4: Preparation with ProTaper instruments up to F2 instrument. Group 5: Preparation with ProTaper Next instruments up to X2 instrument. No procedure was applied to control group. The roots were sectioned horizontally at 3, 6 and 9 mm from the apex and examined. Absence or presence of dentinal microcracks was noted. The Chi-square test was performed to compare the appearance of cracked roots between all groups. There were no significant differences among the groups (P > 0.05). In conclusion, except the hand file and control group, all experimental groups showed microcrack formations.

24 DOF EMG controlled hybrid actuated prosthetic hand.

PubMed

Atasoy, A; Kaya, E; Toptas, E; Kuchimov, S; Kaplanoglu, E; Ozkan, M

2016-08-01

A complete mechanical design concept of an electromyogram (EMG) controlled hybrid prosthetic hand, with 24 degree of freedom (DOF) anthropomorphic structure is presented. Brushless DC motors along with Shape Memory Alloy (SMA) actuators are used to achieve dexterous functionality. An 8 channel EMG is used for detecting 7 basic hand gestures for control purposes. The prosthetic hand will be integrated with the Neural Network (NNE) based controller in the next phase of the study.

Touch the table before the target: contact with an underlying surface may assist the development of precise visually controlled reach and grasp movements in human infants.

PubMed

Karl, Jenni M; Wilson, Alexis M; Bertoli, Marisa E; Shubear, Noor S

2018-05-24

Multiple motor channel theory posits that skilled hand movements arise from the coordinated activation of separable neural circuits in parietofrontal cortex, each of which produces a distinct movement and responds to different sensory inputs. Prehension, the act of reaching to grasp an object, consists of at least two movements: a reach movement that transports the hand to a target location and a grasp movement that shapes and closes the hand for target acquisition. During early development, discrete pre-reach and pre-grasp movements are refined based on proprioceptive and tactile feedback, but are gradually coordinated together into a singular hand preshaping movement under feedforward visual control. The neural and behavioural factors that enable this transition are currently unknown. In an attempt to identify such factors, the present descriptive study used frame-by-frame video analysis to examine 9-, 12-, and 15-month-old infants, along with sighted and unsighted adults, as they reached to grasp small ring-shaped pieces of cereal (Cheerios) resting on a table. Compared to sighted adults, infants and unsighted adults were more likely to make initial contact with the underlying table before they contacted the target. The way in which they did so was also similar in that they generally contacted the table with the tip of the thumb and/or pinky finger, a relatively open hand, and poor reach accuracy. Despite this, infants were similar to sighted adults in that they tended to use a pincer digit, defined as the tip of the thumb or index finger, to subsequently contact the target. Only in infants was this ability related to their having made prior contact with the underlying table. The results are discussed in relation to the idea that initial contact with an underlying table or surface may assist infants in learning to use feedforward visual control to direct their digits towards a precise visual target.

Specialization of the left supramarginal gyrus for hand-independent praxis representation is not related to hand dominance.

PubMed

Króliczak, Gregory; Piper, Brian J; Frey, Scott H

2016-12-01

Data from focal brain injury and functional neuroimaging studies implicate a distributed network of parieto-fronto-temporal areas in the human left cerebral hemisphere as playing distinct roles in the representation of meaningful actions (praxis). Because these data come primarily from right-handed individuals, the relationship between left cerebral specialization for praxis representation and hand dominance remains unclear. We used functional magnetic resonance imaging (fMRI) to evaluate the hypothesis that strongly left-handed (right hemisphere motor dominant) adults also exhibit this left cerebral specialization. Participants planned familiar actions for subsequent performance with the left or right hand in response to transitive (e.g., "pounding") or intransitive (e.g. "waving") action words. In linguistic control trials, cues denoted non-physical actions (e.g., "believing"). Action planning was associated with significant, exclusively left-lateralized and extensive increases of activity in the supramarginal gyrus (SMg), and more focal modulations in the left caudal middle temporal gyrus (cMTg). This activity was hand- and gesture-independent, i.e., unaffected by the hand involved in subsequent action performance, and the type of gesture (i.e., transitive or intransitive). Compared directly with right-handers, left-handers exhibited greater involvement of the right angular gyrus (ANg) and dorsal premotor cortex (dPMC), which is indicative of a less asymmetric functional architecture for praxis representation. We therefore conclude that the organization of mechanisms involved in planning familiar actions is influenced by one's motor dominance. However, independent of hand dominance, the left SMg and cMTg are specialized for ideomotor transformations-the integration of conceptual knowledge and motor representations into meaningful actions. These findings support the view that higher-order praxis representation and lower-level motor dominance rely on dissociable mechanisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Specialization of the left supramarginal gyrus for hand-independent praxis representation is not related to hand dominance

PubMed Central

Króliczak, Gregory; Piper, Brian J.; Frey, Scott H.

2016-01-01

Data from focal brain injury and functional neuroimaging studies implicate a distributed network of parieto-fronto-temporal areas in the human left cerebral hemisphere as playing distinct roles in the representation of meaningful actions (praxis). Because these data come primarily from right-handed individuals, the relationship between left cerebral specialization for praxis representation and hand dominance remains unclear. We used functional magnetic resonance imaging (fMRI) to evaluate the hypothesis that strongly left-handed (right hemisphere motor dominant) adults also exhibit this left cerebral specialization. Participants planned familiar actions for subsequent performance with the left or right hand in response to transitive (e.g., “pounding”) or intransitive (e.g. “waving”) action words. In linguistic control trials, cues denoted non-physical actions (e.g., “believing”). Action planning was associated with significant, exclusively left-lateralized and extensive increases of activity in the supramarginal gyrus (SMg), and more focal modulations in the left caudal middle temporal gyrus (cMTg). This activity was hand- and gesture-independent, i.e., unaffected by the hand involved in subsequent action performance, and the type of gesture (i.e., transitive or intransitive). Compared directly with right-handers, left-handers exhibited greater involvement of the right angular gyrus (ANg) and dorsal premotor cortex (dPMC), which is indicative of a less asymmetric functional architecture for praxis representation. We therefore conclude that the organization of mechanisms involved in planning familiar actions is influenced by one’s motor dominance. However, independent of hand dominance, the left SMg and cMTg are specialized for ideomotor transformations—the integration of conceptual knowledge and motor representations into meaningful actions. These findings support the view that higher-order praxis representation and lower-level motor dominance rely on dissociable mechanisms. PMID:27020138

Vibration-reducing gloves: transmissibility at the palm of the hand in three orthogonal directions

PubMed Central

McDowell, Thomas W.; Dong, Ren G.; Welcome, Daniel E.; Xu, Xueyan S.; Warren, Christopher

2015-01-01

Vibration-reducing (VR) gloves are commonly used as a means to help control exposures to hand-transmitted vibrations generated by powered hand tools. The objective of this study was to characterise the vibration transmissibility spectra and frequency-weighted vibration transmissibility of VR gloves at the palm of the hand in three orthogonal directions. Seven adult males participated in the evaluation of seven glove models using a three-dimensional hand–arm vibration test system. Three levels of hand coupling force were applied in the experiment. This study found that, in general, VR gloves are most effective at reducing vibrations transmitted to the palm along the forearm direction. Gloves that are found to be superior at reducing vibrations in the forearm direction may not be more effective in the other directions when compared with other VR gloves. This casts doubts on the validity of the standardised glove screening test. Practitioner Summary This study used human subjects to measure three-dimensional vibration transmissibility of vibration-reducing gloves at the palm and identified their vibration attenuation characteristics. This study found the gloves to be most effective at reducing vibrations along the forearm direction. These gloves did not effectively attenuate vibration along the handle axial direction. PMID:24160755

Large-scale neural networks and the lateralization of motivation and emotion.

PubMed

Tops, Mattie; Quirin, Markus; Boksem, Maarten A S; Koole, Sander L

2017-09-01

Several lines of research in animals and humans converge on the distinction between two basic large-scale brain networks of self-regulation, giving rise to predictive and reactive control systems (PARCS). Predictive (internally-driven) and reactive (externally-guided) control are supported by dorsal versus ventral corticolimbic systems, respectively. Based on extant empirical evidence, we demonstrate how the PARCS produce frontal laterality effects in emotion and motivation. In addition, we explain how this framework gives rise to individual differences in appraising and coping with challenges. PARCS theory integrates separate fields of research, such as research on the motivational correlates of affect, EEG frontal alpha power asymmetry and implicit affective priming effects on cardiovascular indicators of effort during cognitive task performance. Across these different paradigms, converging evidence points to a qualitative motivational division between, on the one hand, angry and happy emotions, and, on the other hand, sad and fearful emotions. PARCS suggests that those two pairs of emotions are associated with predictive and reactive control, respectively. PARCS theory may thus generate important new insights on the motivational and emotional dynamics that drive autonomic and homeostatic control processes. Copyright © 2017 Elsevier B.V. All rights reserved.

Microsoft kinect-based artificial perception system for control of functional electrical stimulation assisted grasping.

PubMed

Strbac, Matija; Kočović, Slobodan; Marković, Marko; Popović, Dejan B

2014-01-01

We present a computer vision algorithm that incorporates a heuristic model which mimics a biological control system for the estimation of control signals used in functional electrical stimulation (FES) assisted grasping. The developed processing software acquires the data from Microsoft Kinect camera and implements real-time hand tracking and object analysis. This information can be used to identify temporal synchrony and spatial synergies modalities for FES control. Therefore, the algorithm acts as artificial perception which mimics human visual perception by identifying the position and shape of the object with respect to the position of the hand in real time during the planning phase of the grasp. This artificial perception used within the heuristically developed model allows selection of the appropriate grasp and prehension. The experiments demonstrate that correct grasp modality was selected in more than 90% of tested scenarios/objects. The system is portable, and the components are low in cost and robust; hence, it can be used for the FES in clinical or even home environment. The main application of the system is envisioned for functional electrical therapy, that is, intensive exercise assisted with FES.

Google Glass-Directed Monitoring and Control of Microfluidic Biosensors and Actuators

PubMed Central

Zhang, Yu Shrike; Busignani, Fabio; Ribas, João; Aleman, Julio; Rodrigues, Talles Nascimento; Shaegh, Seyed Ali Mousavi; Massa, Solange; Rossi, Camilla Baj; Taurino, Irene; Shin, Su-Ryon; Calzone, Giovanni; Amaratunga, Givan Mark; Chambers, Douglas Leon; Jabari, Saman; Niu, Yuxi; Manoharan, Vijayan; Dokmeci, Mehmet Remzi; Carrara, Sandro; Demarchi, Danilo; Khademhosseini, Ali

2016-01-01

Google Glass is a recently designed wearable device capable of displaying information in a smartphone-like hands-free format by wireless communication. The Glass also provides convenient control over remote devices, primarily enabled by voice recognition commands. These unique features of the Google Glass make it useful for medical and biomedical applications where hands-free experiences are strongly preferred. Here, we report for the first time, an integral set of hardware, firmware, software, and Glassware that enabled wireless transmission of sensor data onto the Google Glass for on-demand data visualization and real-time analysis. Additionally, the platform allowed the user to control outputs entered through the Glass, therefore achieving bi-directional Glass-device interfacing. Using this versatile platform, we demonstrated its capability in monitoring physical and physiological parameters such as temperature, pH, and morphology of liver- and heart-on-chips. Furthermore, we showed the capability to remotely introduce pharmaceutical compounds into a microfluidic human primary liver bioreactor at desired time points while monitoring their effects through the Glass. We believe that such an innovative platform, along with its concept, has set up a premise in wearable monitoring and controlling technology for a wide variety of applications in biomedicine. PMID:26928456

Google Glass-Directed Monitoring and Control of Microfluidic Biosensors and Actuators

NASA Astrophysics Data System (ADS)

Zhang, Yu Shrike; Busignani, Fabio; Ribas, João; Aleman, Julio; Rodrigues, Talles Nascimento; Shaegh, Seyed Ali Mousavi; Massa, Solange; Rossi, Camilla Baj; Taurino, Irene; Shin, Su-Ryon; Calzone, Giovanni; Amaratunga, Givan Mark; Chambers, Douglas Leon; Jabari, Saman; Niu, Yuxi; Manoharan, Vijayan; Dokmeci, Mehmet Remzi; Carrara, Sandro; Demarchi, Danilo; Khademhosseini, Ali

2016-03-01

Google Glass is a recently designed wearable device capable of displaying information in a smartphone-like hands-free format by wireless communication. The Glass also provides convenient control over remote devices, primarily enabled by voice recognition commands. These unique features of the Google Glass make it useful for medical and biomedical applications where hands-free experiences are strongly preferred. Here, we report for the first time, an integral set of hardware, firmware, software, and Glassware that enabled wireless transmission of sensor data onto the Google Glass for on-demand data visualization and real-time analysis. Additionally, the platform allowed the user to control outputs entered through the Glass, therefore achieving bi-directional Glass-device interfacing. Using this versatile platform, we demonstrated its capability in monitoring physical and physiological parameters such as temperature, pH, and morphology of liver- and heart-on-chips. Furthermore, we showed the capability to remotely introduce pharmaceutical compounds into a microfluidic human primary liver bioreactor at desired time points while monitoring their effects through the Glass. We believe that such an innovative platform, along with its concept, has set up a premise in wearable monitoring and controlling technology for a wide variety of applications in biomedicine.

Google Glass-Directed Monitoring and Control of Microfluidic Biosensors and Actuators.

PubMed

Zhang, Yu Shrike; Busignani, Fabio; Ribas, João; Aleman, Julio; Rodrigues, Talles Nascimento; Shaegh, Seyed Ali Mousavi; Massa, Solange; Baj Rossi, Camilla; Taurino, Irene; Shin, Su-Ryon; Calzone, Giovanni; Amaratunga, Givan Mark; Chambers, Douglas Leon; Jabari, Saman; Niu, Yuxi; Manoharan, Vijayan; Dokmeci, Mehmet Remzi; Carrara, Sandro; Demarchi, Danilo; Khademhosseini, Ali

2016-03-01

Google Glass is a recently designed wearable device capable of displaying information in a smartphone-like hands-free format by wireless communication. The Glass also provides convenient control over remote devices, primarily enabled by voice recognition commands. These unique features of the Google Glass make it useful for medical and biomedical applications where hands-free experiences are strongly preferred. Here, we report for the first time, an integral set of hardware, firmware, software, and Glassware that enabled wireless transmission of sensor data onto the Google Glass for on-demand data visualization and real-time analysis. Additionally, the platform allowed the user to control outputs entered through the Glass, therefore achieving bi-directional Glass-device interfacing. Using this versatile platform, we demonstrated its capability in monitoring physical and physiological parameters such as temperature, pH, and morphology of liver- and heart-on-chips. Furthermore, we showed the capability to remotely introduce pharmaceutical compounds into a microfluidic human primary liver bioreactor at desired time points while monitoring their effects through the Glass. We believe that such an innovative platform, along with its concept, has set up a premise in wearable monitoring and controlling technology for a wide variety of applications in biomedicine.

Microsoft Kinect-Based Artificial Perception System for Control of Functional Electrical Stimulation Assisted Grasping

PubMed Central

Kočović, Slobodan; Popović, Dejan B.

2014-01-01

We present a computer vision algorithm that incorporates a heuristic model which mimics a biological control system for the estimation of control signals used in functional electrical stimulation (FES) assisted grasping. The developed processing software acquires the data from Microsoft Kinect camera and implements real-time hand tracking and object analysis. This information can be used to identify temporal synchrony and spatial synergies modalities for FES control. Therefore, the algorithm acts as artificial perception which mimics human visual perception by identifying the position and shape of the object with respect to the position of the hand in real time during the planning phase of the grasp. This artificial perception used within the heuristically developed model allows selection of the appropriate grasp and prehension. The experiments demonstrate that correct grasp modality was selected in more than 90% of tested scenarios/objects. The system is portable, and the components are low in cost and robust; hence, it can be used for the FES in clinical or even home environment. The main application of the system is envisioned for functional electrical therapy, that is, intensive exercise assisted with FES. PMID:25202707

Multirobot Lunar Excavation and ISRU Using Artificial-Neural-Tissue Controllers

NASA Astrophysics Data System (ADS)

Thangavelautham, Jekanthan; Smith, Alexander; Abu El Samid, Nader; Ho, Alexander; Boucher, Dale; Richard, Jim; D'Eleuterio, Gabriele M. T.

2008-01-01

Automation of site preparation and resource utilization on the Moon with teams of autonomous robots holds considerable promise for establishing a lunar base. Such multirobot autonomous systems would require limited human support infrastructure, complement necessary manned operations and reduce overall mission risk. We present an Artificial Neural Tissue (ANT) architecture as a control system for autonomous multirobot excavation tasks. An ANT approach requires much less human supervision and pre-programmed human expertise than previous techniques. Only a single global fitness function and a set of allowable basis behaviors need be specified. An evolutionary (Darwinian) selection process is used to `breed' controllers for the task at hand in simulation and the fittest controllers are transferred onto hardware for further validation and testing. ANT facilitates `machine creativity', with the emergence of novel functionality through a process of self-organized task decomposition of mission goals. ANT based controllers are shown to exhibit self-organization, employ stigmergy (communication mediated through the environment) and make use of templates (unlabeled environmental cues). With lunar in-situ resource utilization (ISRU) efforts in mind, ANT controllers have been tested on a multirobot excavation task in which teams of robots with no explicit supervision can successfully avoid obstacles, interpret excavation blueprints, perform layered digging, avoid burying or trapping other robots and clear/maintain digging routes.

A virtual reality-based system integrated with fmri to study neural mechanisms of action observation-execution: A proof of concept study

PubMed Central

Adamovich, S.V.; August, K.; Merians, A.; Tunik, E.

2017-01-01

Purpose Emerging evidence shows that interactive virtual environments (VEs) may be a promising tool for studying sensorimotor processes and for rehabilitation. However, the potential of VEs to recruit action observation-execution neural networks is largely unknown. For the first time, a functional MRI-compatible virtual reality system (VR) has been developed to provide a window into studying brain-behavior interactions. This system is capable of measuring the complex span of hand-finger movements and simultaneously streaming this kinematic data to control the motion of representations of human hands in virtual reality. Methods In a blocked fMRI design, thirteen healthy subjects observed, with the intent to imitate (OTI), finger sequences performed by the virtual hand avatar seen in 1st person perspective and animated by pre-recorded kinematic data. Following this, subjects imitated the observed sequence while viewing the virtual hand avatar animated by their own movement in real-time. These blocks were interleaved with rest periods during which subjects viewed static virtual hand avatars and control trials in which the avatars were replaced with moving non-anthropomorphic objects. Results We show three main findings. First, both observation with intent to imitate and imitation with real-time virtual avatar feedback, were associated with activation in a distributed frontoparietal network typically recruited for observation and execution of real-world actions. Second, we noted a time-variant increase in activation in the left insular cortex for observation with intent to imitate actions performed by the virtual avatar. Third, imitation with virtual avatar feedback (relative to the control condition) was associated with a localized recruitment of the angular gyrus, precuneus, and extrastriate body area, regions which are (along with insular cortex) associated with the sense of agency. Conclusions Our data suggest that the virtual hand avatars may have served as disembodied training tools in the observation condition and as embodied “extensions” of the subject’s own body (pseudo-tools) in the imitation. These data advance our understanding of the brain-behavior interactions when performing actions in VE and have implications in the development of observation- and imitation-based VR rehabilitation paradigms. PMID:19531876

Association of hand and arm disinfection with asthma control in US nurses.

PubMed

Dumas, Orianne; Varraso, Raphäelle; Boggs, Krislyn M; Descatha, Alexis; Henneberger, Paul K; Quinot, Catherine; Speizer, Frank E; Zock, Jan-Paul; Le Moual, Nicole; Camargo, Carlos A

2018-05-01

To investigate the association between occupational exposure to disinfectants/antiseptics used for hand hygiene and asthma control in nurses. In 2014, we invited female nurses with asthma drawn from the Nurses' Health Study II to complete two supplemental questionnaires on their occupation and asthma (cross-sectional study, response rate: 80%). Among 4055 nurses (mean age: 59 years) with physician-diagnosed asthma and asthma medication use in the past year, we examined asthma control, as defined by the Asthma Control Test (ACT). Nurses were asked about the daily frequency of hand hygiene tasks: 'wash/scrub hands with disinfectants/hand sanitizers' (hand hygiene) and 'wash/scrub arms with disinfecting products' (surrogate of surgical hand/arm antisepsis). Analyses were adjusted for age, race, ethnicity, smoking status and body mass index. Nurses with partly controlled asthma (ACT: 20-24, 50%) and poorly controlled asthma (ACT ≤19, 18%) were compared with nurses with controlled asthma (ACT=25, 32%). In separate models, both hand and arm hygiene were associated with poorly controlled asthma. After mutual adjustment, only arm hygiene was associated with poorly controlled asthma: OR (95% CI) for <1 time/day, 1.38 (1.06 to 1.80); ≥1 time/day, 1.96 (1.52 to 2.51), versus never. We observed a consistent dose-response relationship between frequency of arm hygiene tasks (never to >10 times/day) and poor asthma control. Associations persisted after further adjustment for surfaces/instruments disinfection tasks. Frequency of hand/arm hygiene tasks in nurses was associated with poor asthma control. The results suggest an adverse effect of products used for surgical hand/arm antisepsis. This potential new occupational risk factor for asthma warrants further study. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Social-cognitive antecedents of hand washing: Action control bridges the planning-behaviour gap.

PubMed

Reyes Fernández, Benjamín; Knoll, Nina; Hamilton, Kyra; Schwarzer, Ralf

2016-08-01

To examine motivational and volitional factors for hand washing in young adults, using the Health Action Process Approach (HAPA) as a theoretical framework. In a longitudinal design with two measurement points, six weeks apart, university students (N = 440) completed paper-based questionnaires. Prior hand washing frequency, self-efficacy, outcome expectancies, intention and action planning were measured at baseline, and coping planning, action control and hand washing frequency were measured at follow-up. A theory-based structural equation model was specified. In line with the HAPA, the motivational factors of self-efficacy and outcome expectancies predicted intention, whereas the volitional factors of planning and action control mediated between intention and changes in hand washing frequency. Action control was confirmed as the most proximal factor on hand washing behaviour, thus representing a bridge of the planning-behaviour gap. Both motivational and volitional processes are important to consider in the improvement of hand hygiene practices. Moreover, the statistically significant effects for planning and action control illustrate the importance of these key self-regulatory factors in the prediction of hand hygiene. The current study highlights the importance of adopting models that account for motivational and volitional factors to better understand hand washing behaviour.

The visual development of hand-centered receptive fields in a neural network model of the primate visual system trained with experimentally recorded human gaze changes

PubMed Central

Galeazzi, Juan M.; Navajas, Joaquín; Mender, Bedeho M. W.; Quian Quiroga, Rodrigo; Minini, Loredana; Stringer, Simon M.

2016-01-01

ABSTRACT Neurons have been found in the primate brain that respond to objects in specific locations in hand-centered coordinates. A key theoretical challenge is to explain how such hand-centered neuronal responses may develop through visual experience. In this paper we show how hand-centered visual receptive fields can develop using an artificial neural network model, VisNet, of the primate visual system when driven by gaze changes recorded from human test subjects as they completed a jigsaw. A camera mounted on the head captured images of the hand and jigsaw, while eye movements were recorded using an eye-tracking device. This combination of data allowed us to reconstruct the retinal images seen as humans undertook the jigsaw task. These retinal images were then fed into the neural network model during self-organization of its synaptic connectivity using a biologically plausible trace learning rule. A trace learning mechanism encourages neurons in the model to learn to respond to input images that tend to occur in close temporal proximity. In the data recorded from human subjects, we found that the participant’s gaze often shifted through a sequence of locations around a fixed spatial configuration of the hand and one of the jigsaw pieces. In this case, trace learning should bind these retinal images together onto the same subset of output neurons. The simulation results consequently confirmed that some cells learned to respond selectively to the hand and a jigsaw piece in a fixed spatial configuration across different retinal views. PMID:27253452

The visual development of hand-centered receptive fields in a neural network model of the primate visual system trained with experimentally recorded human gaze changes.

PubMed

Galeazzi, Juan M; Navajas, Joaquín; Mender, Bedeho M W; Quian Quiroga, Rodrigo; Minini, Loredana; Stringer, Simon M

2016-01-01

Neurons have been found in the primate brain that respond to objects in specific locations in hand-centered coordinates. A key theoretical challenge is to explain how such hand-centered neuronal responses may develop through visual experience. In this paper we show how hand-centered visual receptive fields can develop using an artificial neural network model, VisNet, of the primate visual system when driven by gaze changes recorded from human test subjects as they completed a jigsaw. A camera mounted on the head captured images of the hand and jigsaw, while eye movements were recorded using an eye-tracking device. This combination of data allowed us to reconstruct the retinal images seen as humans undertook the jigsaw task. These retinal images were then fed into the neural network model during self-organization of its synaptic connectivity using a biologically plausible trace learning rule. A trace learning mechanism encourages neurons in the model to learn to respond to input images that tend to occur in close temporal proximity. In the data recorded from human subjects, we found that the participant's gaze often shifted through a sequence of locations around a fixed spatial configuration of the hand and one of the jigsaw pieces. In this case, trace learning should bind these retinal images together onto the same subset of output neurons. The simulation results consequently confirmed that some cells learned to respond selectively to the hand and a jigsaw piece in a fixed spatial configuration across different retinal views.

Multiple sensor smart robot hand with force control

NASA Technical Reports Server (NTRS)

Killion, Richard R.; Robinson, Lee R.; Bejczy, Antal

1987-01-01

A smart robot hand developed at JPL for the Protoflight Manipulator Arm (PFMA) is described. The development of this smart hand was based on an integrated design and subsystem architecture by considering mechanism, electronics, sensing, control, display, and operator interface in an integrated design approach. The mechanical details of this smart hand and the overall subsystem are described elsewhere. The sensing and electronics components of the JPL/PFMA smart hand are summarized and it is described in some detail in control capabilities.

What interests them in the pictures?--differences in eye-tracking between rhesus monkeys and humans.

PubMed

Hu, Ying-Zhou; Jiang, Hui-Hui; Liu, Ci-Rong; Wang, Jian-Hong; Yu, Cheng-Yang; Carlson, Synnöve; Yang, Shang-Chuan; Saarinen, Veli-Matti; Rizak, Joshua D; Tian, Xiao-Guang; Tan, Hen; Chen, Zhu-Yue; Ma, Yuan-Ye; Hu, Xin-Tian

2013-10-01

Studies estimating eye movements have demonstrated that non-human primates have fixation patterns similar to humans at the first sight of a picture. In the current study, three sets of pictures containing monkeys, humans or both were presented to rhesus monkeys and humans. The eye movements on these pictures by the two species were recorded using a Tobii eye-tracking system. We found that monkeys paid more attention to the head and body in pictures containing monkeys, whereas both monkeys and humans paid more attention to the head in pictures containing humans. The humans always concentrated on the eyes and head in all the pictures, indicating the social role of facial cues in society. Although humans paid more attention to the hands than monkeys, both monkeys and humans were interested in the hands and what was being done with them in the pictures. This may suggest the importance and necessity of hands for survival. Finally, monkeys scored lower in eye-tracking when fixating on the pictures, as if they were less interested in looking at the screen than humans. The locations of fixation in monkeys may provide insight into the role of eye movements in an evolutionary context.

3D Printed Robotic Hand

NASA Technical Reports Server (NTRS)

Pizarro, Yaritzmar Rosario; Schuler, Jason M.; Lippitt, Thomas C.

2013-01-01

Dexterous robotic hands are changing the way robots and humans interact and use common tools. Unfortunately, the complexity of the joints and actuations drive up the manufacturing cost. Some cutting edge and commercially available rapid prototyping machines now have the ability to print multiple materials and even combine these materials in the same job. A 3D model of a robotic hand was designed using Creo Parametric 2.0. Combining "hard" and "soft" materials, the model was printed on the Object Connex350 3D printer with the purpose of resembling as much as possible the human appearance and mobility of a real hand while needing no assembly. After printing the prototype, strings where installed as actuators to test mobility. Based on printing materials, the manufacturing cost of the hand was $167, significantly lower than other robotic hands without the actuators since they have more complex assembly processes.

Human strength simulations for one and two-handed tasks in zero gravity

NASA Technical Reports Server (NTRS)

1972-01-01

A description is given of a three dimensional hand force capability model for the seated operator and a biomechanical model for analysis of symmetric sagittal plane activities. The models are used to simulate and study human strengths for one and two handed tasks in zero gravity. Specific conditions considered include: (1) one hand active, (2) both hands active but with different force directions on each, (3) body bracing situations provided by portable foot restraint when standing and lap belt when seated, (4) static or slow movement tasks with maximum length of 4 seconds and a minimum rest of 5 minutes between exertions, and (5) wide range of hand positions relative to either the feet or bisection of a line connecting the hip centers. Simulations were also made for shirt sleeved individuals and for the male population strengths with anthropometry matching that of astronauts.

Finger Length Ratios in Serbian Transsexuals

PubMed Central

Vujović, Svetlana; Popović, Srdjan; Mrvošević Marojević, Ljiljana; Ivović, Miomira; Tančić-Gajić, Milina; Stojanović, Miloš; Marina, Ljiljana V.; Barać, Marija; Barać, Branko; Kovačević, Milena; Duišin, Dragana; Barišić, Jasmina; Djordjević, Miroslav L.; Micić, Dragan

2014-01-01

Atypical prenatal hormone exposure could be a factor in the development of transsexualism. There is evidence that the 2nd and 4th digit ratio (2D : 4D) associates negatively with prenatal testosterone and positively with estrogens. The aim was to assess the difference in 2D : 4D between female to male transsexuals (FMT) and male to female transsexuals (MFT) and controls. We examined 42 MFT, 38 FMT, and 45 control males and 48 control females. Precise measurements were made by X-rays at the ventral surface of both hands from the basal crease of the digit to the tip using vernier calliper. Control male and female patients had larger 2D : 4D of the right hand when compared to the left hand. Control male's left hand ratio was lower than in control female's left hand. There was no difference in 2D : 4D between MFT and control males. MFT showed similar 2D : 4D of the right hand with control women indicating possible influencing factor in embryogenesis and consequently finger length changes. FMT showed the lowest 2D : 4D of the left hand when compared to the control males and females. Results of our study go in favour of the biological aetiology of transsexualism. PMID:24982993

Development of anthropomorphic robotic hand driven by Pneumatic Artificial Muscles for robotic applications

NASA Astrophysics Data System (ADS)

Farag, Mohannad; Zainul Azlan, Norsinnira; Hayyan Alsibai, Mohammed

2018-04-01

This paper presents the design and fabrication of a three-fingered anthropomorphic robotic hand. The fingers are driven by tendons and actuated by human muscle-like actuators known as Pneumatic Artificial Muscle (PAM). The proposed design allows the actuators to be mounted outside the hand where each finger can be driven by one PAM actuator and six indirectly interlinked tendons. With this design, the three-fingered hand has a compact size and a lightweight with a mass of 150.25 grams imitating the human being hand in terms of size and weight. The hand also successfully grasped objects with different shapes and weights up to 500 g. Even though the number of PAM actuators equals the number of Degrees of Freedom (DOF), the design guarantees driving of three joints by only one actuator reducing the number of required actuators from 3 to 1. Therefore, this hand is suitable for researches of robotic applications in terms of design, cost and ability to be equipped with several types of sensors.

Postural Hand Synergies during Environmental Constraint Exploitation

PubMed Central

Della Santina, Cosimo; Bianchi, Matteo; Averta, Giuseppe; Ciotti, Simone; Arapi, Visar; Fani, Simone; Battaglia, Edoardo; Catalano, Manuel Giuseppe; Santello, Marco; Bicchi, Antonio

2017-01-01

Humans are able to intuitively exploit the shape of an object and environmental constraints to achieve stable grasps and perform dexterous manipulations. In doing that, a vast range of kinematic strategies can be observed. However, in this work we formulate the hypothesis that such ability can be described in terms of a synergistic behavior in the generation of hand postures, i.e., using a reduced set of commonly used kinematic patterns. This is in analogy with previous studies showing the presence of such behavior in different tasks, such as grasping. We investigated this hypothesis in experiments performed by six subjects, who were asked to grasp objects from a flat surface. We quantitatively characterized hand posture behavior from a kinematic perspective, i.e., the hand joint angles, in both pre-shaping and during the interaction with the environment. To determine the role of tactile feedback, we repeated the same experiments but with subjects wearing a rigid shell on the fingertips to reduce cutaneous afferent inputs. Results show the persistence of at least two postural synergies in all the considered experimental conditions and phases. Tactile impairment does not alter significantly the first two synergies, and contact with the environment generates a change only for higher order Principal Components. A good match also arises between the first synergy found in our analysis and the first synergy of grasping as quantified by previous work. The present study is motivated by the interest of learning from the human example, extracting lessons that can be applied in robot design and control. Thus, we conclude with a discussion on implications for robotics of our findings. PMID:28900393

Planar covariance of upper and lower limb elevation angles during hand-foot crawling in healthy young adults.

PubMed

MacLellan, M J; Catavitello, G; Ivanenko, Y P; Lacquaniti, F

2017-11-01

Habitual quadrupeds have been shown to display a planar covariance of segment elevation angle waveforms in the fore and hind limbs during many forms of locomotion. The purpose of the current study was to determine if humans generate similar patterns in the upper and lower limbs during hand-foot crawling. Nine healthy young adults performed hand-foot crawling on a treadmill at speeds of 1, 2, and 3 km/h. A principal component analysis (PCA) was applied to the segment elevation angle waveforms for the upper (upper arm, lower arm, and hand) and lower (thigh, shank, and foot) limbs separately. The planarity of the elevation angle waveforms was determined using the sum of the variance explained by the first two PCs and the orientation of the covariance plane was quantified using the direction cosines of the eigenvector orthogonal to the plane, projected upon each of the segmental semi-axes. Results showed that planarity of segment elevation angles was maintained in the upper and lower limbs (explained variance >97%), although a slight decrease was present in the upper limb when crawling at 3 km/h. The orientation of the covariance plane was highly limb-specific, consistent with animal studies and possibly related to the functional neural control differences between the upper and lower limbs. These results may suggest that the motor patterns stored in the central nervous system for quadrupedal locomotion may be retained through evolution and may still be exploited when humans perform such tasks.

Volumetric Effects of Motor Cortex Injury on Recovery of Ipsilesional Dexterous Movements

PubMed Central

Darling, Warren G.; Pizzimenti, Marc A.; Hynes, Stephanie M.; Rotella, Diane L.; Headley, Grant; Ge, Jizhi; Stilwell-Morecraft, Kimberly S.; McNeal, David W.; Solon-Cline, Kathryn M.; Morecraft, Robert J.

2011-01-01

Damage to the motor cortex of one hemisphere has classically been associated with contralateral upper limb paresis, but recent patient studies have identified deficits in both upper limbs. In non-human primates, we tested the hypothesis that the severity of ipsilesional upper limb motor impairment in the early post-injury phase depends on the volume of gray and white matter damage of the motor areas of the frontal lobe. We also postulated that substantial recovery would accompany minimal task practice and that ipsilesional limb recovery would be correlated with recovery of the contralesional limb. Gross (reaching) and fine hand motor functions were assessed for 3-12 months post-injury using two motor tests. Volumes of white and gray matter lesions were assessed using quantitative histology. Early changes in post-lesion motor performance were inversely correlated with white matter lesion volume indicating that larger lesions produced greater decreases in ipsilesional hand movement control. All monkeys showed improvements in ipsilesional hand motor skill during the post-lesion period, with reaching skill improvements being positively correlated with total lesion volume indicating larger lesions were associate with greater ipsilesional motor skill recovery. We suggest that reduced trans-callosal inhibition from the lesioned hemisphere may play a role in the observed skill improvements. Our findings show that significant ipsilesional hand motor recovery is likely to accompany injury limited to frontal motor areas. In humans, more pronounced ipsilesional motor deficits that invariably develop after stroke may, in part, be a consequence of more extensive subcortical white and gray matter damage. PMID:21703261

A community-randomised controlled trial promoting waterless hand sanitizer and handwashing with soap, Dhaka, Bangladesh.

PubMed

Luby, Stephen P; Kadir, Mohammad Abdul; Yushuf Sharker, M A; Yeasmin, Farzana; Unicomb, Leanne; Sirajul Islam, M

2010-12-01

To pilot two intensive hand hygiene promotion interventions, one using soap and one using a waterless hand sanitizer, in low-income housing compounds in Dhaka, Bangladesh and assess subsequent changes in handwashing behaviour and hand microbiology. Fieldworkers randomized 30 housing compounds: 10 received handwashing promotion with free soap, 10 received handwashing promotion with free waterless hand sanitizer and 10 were non-intervention controls. Fieldworkers assessed handwashing behaviour by structured observation and collected hand rinse specimens. At baseline, compound residents washed their hands with soap 26% of the time after defecation and 30% after cleaning a child's anus but <1% at other times. Compared with baseline, residents of soap intervention compounds were much more likely to wash their hands with soap after faecal contact (85-91%), before preparing food (26%) and before eating (26%). Compounds that received waterless hand sanitizer cleansed their hands more commonly than control compounds that used soap (10.4%vs. 2.3%), but less commonly than soap intervention compounds used soap (25%). Post-intervention hand rinse samples from soap and sanitizer compounds had lower concentrations of faecal indicator bacteria compared with baseline and control compounds. Waterless hand sanitizer was readily adopted by this low-income community and reduced hand contamination but did not improve the frequency of handwashing compared with soap. Future deployments of waterless hand sanitizers may improve hand hygiene more effectively by targeting settings where soap and water is unavailable. © 2010 Blackwell Publishing Ltd.

Low-Fatigue Hand Controller For Remote Manipulator

NASA Technical Reports Server (NTRS)

Maclaren, Brice; Mcmurray, Gary; Lipkin, Harvey

1993-01-01

Universal master controller used in brace mode, in which user's forearm rests atop upper (forearm) module. Alternatively, user manipulates hand controller in side mode, which gives greater latitude for motion but requires more muscular effort. Controller provides six degrees of freedom and reflects, back to user, scaled versions of forces experienced by manipulator. Manipulator designed to condense work space into user's natural work volume. Operated by both right-handed and left-handed users. Does not interfere with user's natural movements or obstruct line of sight. Controller compact and portable.

Human parvovirus B19 in childhood acute lymphoblastic leukaemia in Basrah.

PubMed

Ibrahem, Wijdan Nazar; Hasony, Hassan Jaber; Hassan, Jenan Ghulam

2014-01-01

To investigate the association of human parvovirus B19 infection with the onset of acute lymphoblastic leukaemia and its effect on TEL-AML-1 fusion gene and the presence of mutant P53. The case-control study was conducted at Basrah Hospital for Paediatrics and Gynaecology, Basrah, Iraq, from May 2009 to April 2010. A total of 100 blood samples were collected from 40 newly diagnosed cases and 60 healthy children to serve as control matched by age and gender. Human parvovirus B19-IgG and anti-P53 antibody were detected by enzyme-linked immunosorbent assay and TEL-AML-1 fusion gene was detected by reverse transcriptase-polymerase chain reaction on extracted ribonucleic acid from fresh blood samples using specified primers. SPSS 15 was used for statistical analysis. A higher proportion of human parvovirus B19-positive cases was found in leukaemic patients (n=19; 47.5%) compared to 12 (20%) in the control group (p<0.05). There was significant association between TEL-AML-1 translocation and human parvovirus-B19 infection as 10 (71.4%) of TEL-AML-1 translocation-positive cases had human parvovirus-B19 IgG. On the other hand, there was no association between such infections and P53 gene mutation in the patients. Human parvovirus-B19 infection is common in the population, with higher prevalence among leukaemic patients with significant association between human parvovirus-B19 and TEL-AML-1 fusion gene in patients of acute lymphoblastic leukaemia.

The All-in-One Human Resource Policy of Taiwan's Hand-in-Hand Program

ERIC Educational Resources Information Center

Ho, Hsuan-fu; Lin, Liang-Ching

2012-01-01

The Taiwan Government launched the Hand-in-Hand After-School Care Program in 2006 with several goals: In addition to providing disadvantaged students with supplemental learning opportunities, this highly ambitious government program hopes to provide increased employment opportunities for substitute teachers and low-income college students, and…

Circuit For Control Of Electromechanical Prosthetic Hand

NASA Technical Reports Server (NTRS)

Bozeman, Richard J., Jr.

1995-01-01

Proposed circuit for control of electromechanical prosthetic hand derives electrical control signals from shoulder movements. Updated, electronic version of prosthesis, that includes two hooklike fingers actuated via cables from shoulder harness. Circuit built around favored shoulder harness, provides more dexterous movement, without incurring complexity of computer-controlled "bionic" or hydraulically actuated devices. Additional harness and potentiometer connected to similar control circuit mounted on other shoulder. Used to control stepping motor rotating hand about prosthetic wrist to one of number of angles consistent with number of digital outputs. Finger-control signals developed by circuit connected to first shoulder harness transmitted to prosthetic hand via sliprings at prosthetic wrist joint.

Perceptual attraction in tool use: evidence for a reliability-based weighting mechanism.

PubMed

Debats, Nienke B; Ernst, Marc O; Heuer, Herbert

2017-04-01

Humans are well able to operate tools whereby their hand movement is linked, via a kinematic transformation, to a spatially distant object moving in a separate plane of motion. An everyday example is controlling a cursor on a computer monitor. Despite these separate reference frames, the perceived positions of the hand and the object were found to be biased toward each other. We propose that this perceptual attraction is based on the principles by which the brain integrates redundant sensory information of single objects or events, known as optimal multisensory integration. That is, 1 ) sensory information about the hand and the tool are weighted according to their relative reliability (i.e., inverse variances), and 2 ) the unisensory reliabilities sum up in the integrated estimate. We assessed whether perceptual attraction is consistent with optimal multisensory integration model predictions. We used a cursor-control tool-use task in which we manipulated the relative reliability of the unisensory hand and cursor position estimates. The perceptual biases shifted according to these relative reliabilities, with an additional bias due to contextual factors that were present in experiment 1 but not in experiment 2 The biased position judgments' variances were, however, systematically larger than the predicted optimal variances. Our findings suggest that the perceptual attraction in tool use results from a reliability-based weighting mechanism similar to optimal multisensory integration, but that certain boundary conditions for optimality might not be satisfied. NEW & NOTEWORTHY Kinematic tool use is associated with a perceptual attraction between the spatially separated hand and the effective part of the tool. We provide a formal account for this phenomenon, thereby showing that the process behind it is similar to optimal integration of sensory information relating to single objects. Copyright © 2017 the American Physiological Society.

Real-time myoelectric control of a multi-fingered hand prosthesis using principal components analysis.

PubMed

Matrone, Giulia C; Cipriani, Christian; Carrozza, Maria Chiara; Magenes, Giovanni

2012-06-15

In spite of the advances made in the design of dexterous anthropomorphic hand prostheses, these sophisticated devices still lack adequate control interfaces which could allow amputees to operate them in an intuitive and close-to-natural way. In this study, an anthropomorphic five-fingered robotic hand, actuated by six motors, was used as a prosthetic hand emulator to assess the feasibility of a control approach based on Principal Components Analysis (PCA), specifically conceived to address this problem. Since it was demonstrated elsewhere that the first two principal components (PCs) can describe the whole hand configuration space sufficiently well, the controller here employed reverted the PCA algorithm and allowed to drive a multi-DoF hand by combining a two-differential channels EMG input with these two PCs. Hence, the novelty of this approach stood in the PCA application for solving the challenging problem of best mapping the EMG inputs into the degrees of freedom (DoFs) of the prosthesis. A clinically viable two DoFs myoelectric controller, exploiting two differential channels, was developed and twelve able-bodied participants, divided in two groups, volunteered to control the hand in simple grasp trials, using forearm myoelectric signals. Task completion rates and times were measured. The first objective (assessed through one group of subjects) was to understand the effectiveness of the approach; i.e., whether it is possible to drive the hand in real-time, with reasonable performance, in different grasps, also taking advantage of the direct visual feedback of the moving hand. The second objective (assessed through a different group) was to investigate the intuitiveness, and therefore to assess statistical differences in the performance throughout three consecutive days. Subjects performed several grasp, transport and release trials with differently shaped objects, by operating the hand with the myoelectric PCA-based controller. Experimental trials showed that the simultaneous use of the two differential channels paradigm was successful. This work demonstrates that the proposed two-DoFs myoelectric controller based on PCA allows to drive in real-time a prosthetic hand emulator into different prehensile patterns with excellent performance. These results open up promising possibilities for the development of intuitive, effective myoelectric hand controllers.

Coxsackievirus A6: a new emerging pathogen causing hand, foot and mouth disease outbreaks worldwide.

PubMed

Bian, Lianlian; Wang, Yiping; Yao, Xin; Mao, Qunying; Xu, Miao; Liang, Zhenglun

2015-01-01

Enterovirus 71 (EV71) and coxsackievirus A16 (CA16) are the predominant pathogens causing outbreaks of hand, foot and mouth disease (HFMD) worldwide. Other human enterovirus A (HEV-A) serotypes tend to cause only sporadic HFMD cases. However, since a HFMD caused by coxsackievirus A6 broke out in Finland in 2008, CA6 has been identified as the responsible pathogen for a series of HFMD outbreaks in Europe, North America and Asia. Because of the severity of the clinical manifestations and the underestimated public health burden, the epidemic of CA6-associated HFMD presents a new challenge to the control of HFMD. This article reviewed the epidemic characteristics, molecular epidemiology, clinical features and laboratory diagnosis of CA6 infection. The genetic evolution of CA6 strains associated with HFMD was also analyzed. It indicated that the development of a multivalent vaccine combining EV71, CA16 and CA6 is an urgent necessity to control HFMD.

Body cooling in human males by cold-water immersion after vigorous exercise.

PubMed

McDonald, A; Goode, R C; Livingstone, S D; Duffin, J

1984-03-01

Five male subjects were immersed to neck level in a whole-body water calorimeter (water temperature 19 degrees C) on two occasions. One immersion was preceded by 30 min of exercise on a treadmill at 80% of the subjects' maximum heart rate, while the other was preceded by no exercise (control). Ventilation, oxygen consumption, hand-grip strength, and heat loss (measured by calorimetry) results showed no significant differences between resting and exercise trials. Minute ventilation and oxygen consumption increased during the immersion but the magnitude of the increase varied among subjects. There was a significant decrease is isometric hand-grip strength after 30 min of immersion. Rectal temperatures fell faster (0.031 degree C +/- 0.004 degree C/min) for exercised subjects than for controls (0.019 degree C +/- 0.005 degree C/min) between 10 and 45 min of immersion (P less than 0.01). It appears that vigorous preimmersion exercise may shorten survival time in cold water due to an increase in cooling rate.

49 CFR 571.123 - Standard No. 123; Motorcycle controls and displays.

Code of Federal Regulations, 2013 CFR

2013-10-01

...'s right hand from the throttle. Each control located on a left handlebar shall be operable by the operator's left hand throughout its full range without removal of the operator's left hand from the... rear brake control, the control shall be located on the left handlebar. If a scooter with an automatic...

49 CFR 571.123 - Standard No. 123; Motorcycle controls and displays.

Code of Federal Regulations, 2011 CFR

2011-10-01

...'s right hand from the throttle. Each control located on a left handlebar shall be operable by the operator's left hand throughout its full range without removal of the operator's left hand from the... rear brake control, the control shall be located on the left handlebar. If a scooter with an automatic...

49 CFR 571.123 - Standard No. 123; Motorcycle controls and displays.

Code of Federal Regulations, 2012 CFR

2012-10-01

...'s right hand from the throttle. Each control located on a left handlebar shall be operable by the operator's left hand throughout its full range without removal of the operator's left hand from the... rear brake control, the control shall be located on the left handlebar. If a scooter with an automatic...

49 CFR 571.123 - Standard No. 123; Motorcycle controls and displays.

Code of Federal Regulations, 2014 CFR

2014-10-01

...'s right hand from the throttle. Each control located on a left handlebar shall be operable by the operator's left hand throughout its full range without removal of the operator's left hand from the... rear brake control, the control shall be located on the left handlebar. If a scooter with an automatic...

The Expressive Gaze Model: Using Gaze to Express Emotion

DTIC Science & Technology

2010-07-01

World of Warcraft or Oblivion , have thou- sands of computer-controlled nonplayer characters with which users can interact. Producing hand- generated...increasing to the right and the vertical increasing upward. In both cases, 0 degrees is straight ahead. Although the mechani- cal limits of human eye...to gaze from a target directly in front of her to one 60 degrees to her right , while performing these behaviors in a manner that expressed the de

Human Factors and Robotics: Current Status and Future Prospects.

DTIC Science & Technology

1981-10-01

relatively simple "pick and place" machines which have mechanical arms and hands for transferring workpieces, and may be reprogrammable . Japan’s...tasks can consist of self-monitoring of activity or the control of other machines. Spot welding in the manufacture of automobiles represents probably...application alone. On an automobile production line, the robot must be able to remember several different body styles (e.g., 2-door versus 4-door) with

Real-time simulation of hand motion for prosthesis control

PubMed Central

Blana, Dimitra; Chadwick, Edward K.; van den Bogert, Antonie J.; Murray, Wendy M.

2016-01-01

Individuals with hand amputation suffer substantial loss of independence. Performance of sophisticated prostheses is limited by the ability to control them. To achieve natural and simultaneous control of all wrist and hand motions, we propose to use real-time biomechanical simulation to map between residual EMG and motions of the intact hand. Here we describe a musculoskeletal model of the hand using only extrinsic muscles to determine whether real-time performance is possible. Simulation is 1.3 times faster than real time, but the model is locally unstable. Methods are discussed to increase stability and make this approach suitable for prosthesis control. PMID:27868425

Ownership and Agency of an Independent Supernumerary Hand Induced by an Imitation Brain-Computer Interface.

PubMed

Bashford, Luke; Mehring, Carsten

2016-01-01

To study body ownership and control, illusions that elicit these feelings in non-body objects are widely used. Classically introduced with the Rubber Hand Illusion, these illusions have been replicated more recently in virtual reality and by using brain-computer interfaces. Traditionally these illusions investigate the replacement of a body part by an artificial counterpart, however as brain-computer interface research develops it offers us the possibility to explore the case where non-body objects are controlled in addition to movements of our own limbs. Therefore we propose a new illusion designed to test the feeling of ownership and control of an independent supernumerary hand. Subjects are under the impression they control a virtual reality hand via a brain-computer interface, but in reality there is no causal connection between brain activity and virtual hand movement but correct movements are observed with 80% probability. These imitation brain-computer interface trials are interspersed with movements in both the subjects' real hands, which are in view throughout the experiment. We show that subjects develop strong feelings of ownership and control over the third hand, despite only receiving visual feedback with no causal link to the actual brain signals. Our illusion is crucially different from previously reported studies as we demonstrate independent ownership and control of the third hand without loss of ownership in the real hands.

Cyanobacteria and Cyanotoxins: From Impacts on Aquatic Ecosystems and Human Health to Anticarcinogenic Effects

PubMed Central

Zanchett, Giliane; Oliveira-Filho, Eduardo C.

2013-01-01

Cyanobacteria or blue-green algae are among the pioneer organisms of planet Earth. They developed an efficient photosynthetic capacity and played a significant role in the evolution of the early atmosphere. Essential for the development and evolution of species, they proliferate easily in aquatic environments, primarily due to human activities. Eutrophic environments are conducive to the appearance of cyanobacterial blooms that not only affect water quality, but also produce highly toxic metabolites. Poisoning and serious chronic effects in humans, such as cancer, have been described. On the other hand, many cyanobacterial genera have been studied for their toxins with anticancer potential in human cell lines, generating promising results for future research toward controlling human adenocarcinomas. This review presents the knowledge that has evolved on the topic of toxins produced by cyanobacteria, ranging from their negative impacts to their benefits. PMID:24152991

Cyanobacteria and cyanotoxins: from impacts on aquatic ecosystems and human health to anticarcinogenic effects.

PubMed

Zanchett, Giliane; Oliveira-Filho, Eduardo C

2013-10-23

Cyanobacteria or blue-green algae are among the pioneer organisms of planet Earth. They developed an efficient photosynthetic capacity and played a significant role in the evolution of the early atmosphere. Essential for the development and evolution of species, they proliferate easily in aquatic environments, primarily due to human activities. Eutrophic environments are conducive to the appearance of cyanobacterial blooms that not only affect water quality, but also produce highly toxic metabolites. Poisoning and serious chronic effects in humans, such as cancer, have been described. On the other hand, many cyanobacterial genera have been studied for their toxins with anticancer potential in human cell lines, generating promising results for future research toward controlling human adenocarcinomas. This review presents the knowledge that has evolved on the topic of toxins produced by cyanobacteria, ranging from their negative impacts to their benefits.

Impairment of a parieto-premotor network specialized for handwriting in writer's cramp

PubMed Central

Najee-ullah, Muslimah 'Ali; Hallett, Mark

2016-01-01

Handwriting with the dominant hand is a highly skilled task singularly acquired in humans. This skill is the isolated deficit in patients with writer's cramp (WC), a form of dystonia with maladaptive plasticity, acquired through intensive and repetitive motor practice. When a skill is highly trained, a motor program is created in the brain to execute the same movement kinematics regardless of the effector used for the task. The task- and effector-specific symptoms in WC suggest that a problem particularly occurs in the brain when the writing motor program is carried out by the dominant hand. In the present MRI study involving 12 WC patients (with symptoms only affecting the right dominant hand during writing) and 15 age matched unaffected controls we showed that: (1) the writing program recruited the same network regardless of the effector used to write in both groups; (2) dominant handwriting recruited a segregated parieto-premotor network only in the control group; (3) local structural alteration of the premotor area, the motor component of this network, predicted functional connectivity deficits during dominant handwriting and symptom duration in the patient group. Dysfunctions and structural abnormalities of a segregated parieto-premotor network in WC patients suggest that network specialization in focal brain areas is crucial for well-learned motor skill. PMID:27466043

Compact Dexterous Robotic Hand

NASA Technical Reports Server (NTRS)

Lovchik, Christopher Scott (Inventor); Diftler, Myron A. (Inventor)

2001-01-01

A compact robotic hand includes a palm housing, a wrist section, and a forearm section. The palm housing supports a plurality of fingers and one or more movable palm members that cooperate with the fingers to grasp and/or release an object. Each flexible finger comprises a plurality of hingedly connected segments, including a proximal segment pivotally connected to the palm housing. The proximal finger segment includes at least one groove defining first and second cam surfaces for engagement with a cable. A plurality of lead screw assemblies each carried by the palm housing are supplied with power from a flexible shaft rotated by an actuator and output linear motion to a cable move a finger. The cable is secured within a respective groove and enables each finger to move between an opened and closed position. A decoupling assembly pivotally connected to a proximal finger segment enables a cable connected thereto to control movement of an intermediate and distal finger segment independent of movement of the proximal finger segment. The dexterous robotic hand closely resembles the function of a human hand yet is light weight and capable of grasping both heavy and light objects with a high degree of precision.

Analysis of hand contact areas and interaction capabilities during manipulation and exploration.

PubMed

Gonzalez, Franck; Gosselin, Florian; Bachta, Wael

2014-01-01

Manual human-computer interfaces for virtual reality are designed to allow an operator interacting with a computer simulation as naturally as possible. Dexterous haptic interfaces are the best suited for this goal. They give intuitive and efficient control on the environment with haptic and tactile feedback. This paper is aimed at helping in the choice of the interaction areas to be taken into account in the design of such interfaces. The literature dealing with hand interactions is first reviewed in order to point out the contact areas involved in exploration and manipulation tasks. Their frequencies of use are then extracted from existing recordings. The results are gathered in an original graphical interaction map allowing for a simple visualization of the way the hand is used, and compared with a map of mechanoreceptors densities. Then an interaction tree, mapping the relative amount of actions made available through the use of a given contact area, is built and correlated with the losses of hand function induced by amputations. A rating of some existing haptic interfaces and guidelines for their design are finally achieved to illustrate a possible use of the developed graphical tools.

Sensor-based fine telemanipulation for space robotics

NASA Technical Reports Server (NTRS)

Andrenucci, M.; Bergamasco, M.; Dario, P.

1989-01-01

The control of a multifingered hand slave in order to accurately exert arbitrary forces and impart small movements to a grasped object is, at present, a knotty problem in teleoperation. Although a number of articulated robotic hands have been proposed in the recent past for dexterous manipulation in autonomous robots, the possible use of such hands as slaves in teleoperated manipulation is hindered by the present lack of sensors in those hands, and (even if those sensors were available) by the inherent difficulty of transmitting to the master operator the complex sensations elicited by such sensors at the slave level. An analysis of different problems related to sensor-based telemanipulation is presented. The general sensory systems requirements for dexterous slave manipulators are pointed out and the description of a practical sensory system set-up for the developed robotic system is presented. The problem of feeding back to the human master operator stimuli that can be interpreted by his central nervous system as originated during real dexterous manipulation is then considered. Finally, some preliminary work aimed at developing an instrumented glove designed purposely for commanding the master operation and incorporating Kevlar tendons and tension sensors, is discussed.

In vivo assessment of magnesium status in human body using accelerator-based neutron activation measurement of hands: a pilot study.

PubMed

Aslam; Pejović-Milić, A; McNeill, F E; Byun, S H; Prestwich, W V; Chettle, D R

2008-02-01

Magnesium (Mg) is an element essential for many enzymatic reactions in the human body. Various human and animal studies suggest that changes in Mg status are linked to diseases such as cardiac arrhythmia, coronary heart disease, hypertension, premenstrual syndrome, and diabetes mellitus. Thus, knowledge of Mg levels in the human body is needed. A direct measurement of human blood serum, which contains only 0.3% of the total body Mg, is generally used to infer information about the status of Mg in the body. However, in many clinical situations, Mg stored in large levels, for example in bones, muscles, and soft tissues, needs to be monitored either to evaluate the efficacy of a treatment or to study the progression of diseases associated with the deficiency of total body Mg. This work presents a feasibility study of a noninvasive, in vivo neutron activation analysis (IVNAA) technique using the 26Mg (n, gamma) 27Mg reaction to measure Mg levels in human hands. The technique employs the McMaster University high beam current Tandetron accelerator hand irradiation facility and an array of eight NaI (T1) detectors arranged in a 4 pi geometry for delayed counting of the 0.844 and 1.014 MeV gamma rays emitted when 27Mg decays in the irradiated hand. Mg determination in humans using IVNAA of hands has been demonstrated to be feasible, with effective doses as low as one-quarter of those delivered in chest x rays. The overall experimental uncertainty in the measurements is estimated to be approximately 5% (1 sigma). The results are found to be in the range of the in vitro measurements reported for other cortical bones collected from different sites of the human skeleton, which confirms that this technique mainly provides a measure of the amount of Mg in hand bones. The average concentration of Mg determined in human hands is 10.96 +/- 1.25 (+/- 1 SD) mg Mg/g Ca. The coefficient of variation (11%) observed in this study is comparable with or lower than several studies using in vitro measurements reported in the literature and therefore allows for a quantitative intersubject comparison, even if to a limited extent. The features of the developed technique such as its simplicity, rapidity, accuracy, robustness, noninvasive nature, and very effective use of radiation doses, present the technique as a viable diagnostic tool available for trial in a clinical environment.

Augmenting Plasticity Induction in Human Motor Cortex by Disinhibition Stimulation.

PubMed

Cash, Robin F H; Murakami, Takenobu; Chen, Robert; Thickbroom, Gary W; Ziemann, Ulf

2016-01-01

Cellular studies showed that disinhibition, evoked pharmacologically or by a suitably timed priming stimulus, can augment long-term plasticity (LTP) induction. We demonstrated previously that transcranial magnetic stimulation evokes a period of presumably GABA(B)ergic late cortical disinhibition (LCD) in human primary motor cortex (M1). Here, we hypothesized that, in keeping with cellular studies, LCD can augment LTP-like plasticity in humans. In Experiment 1, patterned repetitive TMS was applied to left M1, consisting of 6 trains (intertrain interval, 8 s) of 4 doublets (interpulse interval equal to individual peak I-wave facilitation, 1.3-1.5 ms) spaced by the individual peak LCD (interdoublet interval (IDI), 200-250 ms). This intervention (total of 48 pulses applied over ∼45 s) increased motor-evoked potential amplitude, a marker of corticospinal excitability, in a right hand muscle by 147% ± 4%. Control experiments showed that IDIs shorter or longer than LCD did not result in LTP-like plasticity. Experiment 2 indicated topographic specificity to the M1 hand region stimulated by TMS and duration of the LTP-like plasticity of 60 min. In conclusion, GABA(B)ergic LCD offers a powerful new approach for augmenting LTP-like plasticity induction in human cortex. We refer to this protocol as disinhibition stimulation (DIS). © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Miniaturization of electromagnetic band gap structures for mobile applications

NASA Astrophysics Data System (ADS)

Goussetis, G.; Feresidis, A. P.; Palikaras, G. K.; Kitra, M.; Vardaxoglou, J. C.

2005-12-01

It is well known that interference of the human body affects the performance of the antennas in mobile phone handsets. In this contribution, we investigate the use of miniaturized metallodielectric electromagnetic band gap (MEBG) structures embedded in the case of a mobile handset as a means of decoupling the antenna from the user's hand. The closely coupled MEBG concept is employed to achieve miniaturization of the order of 15:1. Full wave dispersion relations for planar closely coupled MEBG arrays are presented and are validated experimentally. The performance of a prototype handset with an embedded conformal MEBG is assessed experimentally and is compared to a similar prototype without the MEBG. Reduction in the detuning of the antenna because of the human hand by virtue of the MEBG is demonstrated. Moreover, the efficiency of the handset when loaded with a human hand model is shown to improve when the MEBG is in place. The improvements are attributed to the decoupling of the antenna from the user's hand, which is achieved by means of suppressing the fields in the locality of the hand.

Captive Gorillas are Right-Handed for Bimanual Feeding

PubMed Central

Meguerditchian, Adrien; Calcutt, Sarah E.; Lonsdorf, Elizabeth V.; Ross, Stephen R.; Hopkins, William D.

2010-01-01

Predominance of right-handedness has historically been considered as a hallmark of human evolution. Whether nonhuman primates exhibit population-level manual bias remains a controversial topic. Here we investigated the hypothesis that bimanual coordinated activities may be a key-behavior in our ancestors for the emergence and evolution of human population-level right-handedness. To this end, we collected data on hand preferences in 35 captive gorillas (Gorilla gorilla) during simple unimanual reaching and for bimanual coordinated feeding. Unimanual reaching consisted of grasping food on the ground while bimanual feeding consisted of using one hand for holding a food and processing the food item by the opposite hand. No population-level manual bias was found for unimanual actions but, in contrast, gorillas exhibited a significant population-level right-handedness for the bimanual actions. Moreover, the degree of right-handedness for bimanual feeding exceeds any other known reports of hand use in primates, suggesting that lateralization for bimanual feeding is robust in captive gorillas. The collective evidence is discussed in the context of potential continuity of handedness between human and nonhuman primates. PMID:20033918

Prefrontal Cortex Activation Upon a Demanding Virtual Hand-Controlled Task: A New Frontier for Neuroergonomics

PubMed Central

Carrieri, Marika; Petracca, Andrea; Lancia, Stefania; Basso Moro, Sara; Brigadoi, Sabrina; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, Valentina

2016-01-01

Functional near-infrared spectroscopy (fNIRS) is a non-invasive vascular-based functional neuroimaging technology that can assess, simultaneously from multiple cortical areas, concentration changes in oxygenated-deoxygenated hemoglobin at the level of the cortical microcirculation blood vessels. fNIRS, with its high degree of ecological validity and its very limited requirement of physical constraints to subjects, could represent a valid tool for monitoring cortical responses in the research field of neuroergonomics. In virtual reality (VR) real situations can be replicated with greater control than those obtainable in the real world. Therefore, VR is the ideal setting where studies about neuroergonomics applications can be performed. The aim of the present study was to investigate, by a 20-channel fNIRS system, the dorsolateral/ventrolateral prefrontal cortex (DLPFC/VLPFC) in subjects while performing a demanding VR hand-controlled task (HCT). Considering the complexity of the HCT, its execution should require the attentional resources allocation and the integration of different executive functions. The HCT simulates the interaction with a real, remotely-driven, system operating in a critical environment. The hand movements were captured by a high spatial and temporal resolution 3-dimensional (3D) hand-sensing device, the LEAP motion controller, a gesture-based control interface that could be used in VR for tele-operated applications. Fifteen University students were asked to guide, with their right hand/forearm, a virtual ball (VB) over a virtual route (VROU) reproducing a 42 m narrow road including some critical points. The subjects tried to travel as long as possible without making VB fall. The distance traveled by the guided VB was 70.2 ± 37.2 m. The less skilled subjects failed several times in guiding the VB over the VROU. Nevertheless, a bilateral VLPFC activation, in response to the HCT execution, was observed in all the subjects. No correlation was found between the distance traveled by the guided VB and the corresponding cortical activation. These results confirm the suitability of fNIRS technology to objectively evaluate cortical hemodynamic changes occurring in VR environments. Future studies could give a contribution to a better understanding of the cognitive mechanisms underlying human performance either in expert or non-expert operators during the simulation of different demanding/fatiguing activities. PMID:26909033

Prefrontal Cortex Activation Upon a Demanding Virtual Hand-Controlled Task: A New Frontier for Neuroergonomics.

PubMed

Carrieri, Marika; Petracca, Andrea; Lancia, Stefania; Basso Moro, Sara; Brigadoi, Sabrina; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, Valentina

2016-01-01

Functional near-infrared spectroscopy (fNIRS) is a non-invasive vascular-based functional neuroimaging technology that can assess, simultaneously from multiple cortical areas, concentration changes in oxygenated-deoxygenated hemoglobin at the level of the cortical microcirculation blood vessels. fNIRS, with its high degree of ecological validity and its very limited requirement of physical constraints to subjects, could represent a valid tool for monitoring cortical responses in the research field of neuroergonomics. In virtual reality (VR) real situations can be replicated with greater control than those obtainable in the real world. Therefore, VR is the ideal setting where studies about neuroergonomics applications can be performed. The aim of the present study was to investigate, by a 20-channel fNIRS system, the dorsolateral/ventrolateral prefrontal cortex (DLPFC/VLPFC) in subjects while performing a demanding VR hand-controlled task (HCT). Considering the complexity of the HCT, its execution should require the attentional resources allocation and the integration of different executive functions. The HCT simulates the interaction with a real, remotely-driven, system operating in a critical environment. The hand movements were captured by a high spatial and temporal resolution 3-dimensional (3D) hand-sensing device, the LEAP motion controller, a gesture-based control interface that could be used in VR for tele-operated applications. Fifteen University students were asked to guide, with their right hand/forearm, a virtual ball (VB) over a virtual route (VROU) reproducing a 42 m narrow road including some critical points. The subjects tried to travel as long as possible without making VB fall. The distance traveled by the guided VB was 70.2 ± 37.2 m. The less skilled subjects failed several times in guiding the VB over the VROU. Nevertheless, a bilateral VLPFC activation, in response to the HCT execution, was observed in all the subjects. No correlation was found between the distance traveled by the guided VB and the corresponding cortical activation. These results confirm the suitability of fNIRS technology to objectively evaluate cortical hemodynamic changes occurring in VR environments. Future studies could give a contribution to a better understanding of the cognitive mechanisms underlying human performance either in expert or non-expert operators during the simulation of different demanding/fatiguing activities.

Compact Telerobot Hand

NASA Technical Reports Server (NTRS)

Rosheim, Mark; Trechsel, Hans

1993-01-01

Anthropomorphic telerobotic hand contains actuators, joints, sensors, and complex wiring harnesses. Glove protects interior components of hand from dirt and damage. Imitates motions of human fingers and wrist in lifelike and dexterous way. Incorporates pitch/yaw joints in wrist and head knuckles. Hand modular; so fingers removable, interchangeable units. Feature simplifies servicing and maintenance, which must be done frequently in such complex mechanism.

Promoting Instructional Improvement: A Strategic Human Resource Management Perspective

ERIC Educational Resources Information Center

Smylie, Mark A.; Wenzel, Stacy A.

2006-01-01

This report argues that instructional improvement, which goes hand-in-hand with efforts at education reform, can be promoted through the strategic use of human resource management (HRM) practices at the school, district, and state levels. The authors present information from the organizational and management literatures on how firms in several…

Hands-free human-machine interaction with voice

NASA Astrophysics Data System (ADS)

Juang, B. H.

2004-05-01

Voice is natural communication interface between a human and a machine. The machine, when placed in today's communication networks, may be configured to provide automation to save substantial operating cost, as demonstrated in AT&T's VRCP (Voice Recognition Call Processing), or to facilitate intelligent services, such as virtual personal assistants, to enhance individual productivity. These intelligent services often need to be accessible anytime, anywhere (e.g., in cars when the user is in a hands-busy-eyes-busy situation or during meetings where constantly talking to a microphone is either undersirable or impossible), and thus call for advanced signal processing and automatic speech recognition techniques which support what we call ``hands-free'' human-machine communication. These techniques entail a broad spectrum of technical ideas, ranging from use of directional microphones and acoustic echo cancellatiion to robust speech recognition. In this talk, we highlight a number of key techniques that were developed for hands-free human-machine communication in the mid-1990s after Bell Labs became a unit of Lucent Technologies. A video clip will be played to demonstrate the accomplishement.

Design of a Lightweight Soft Robotic Arm Using Pneumatic Artificial Muscles and Inflatable Sleeves.

PubMed

Ohta, Preston; Valle, Luis; King, Jonathan; Low, Kevin; Yi, Jaehyun; Atkeson, Christopher G; Park, Yong-Lae

2018-04-01

As robots begin to interact with humans and operate in human environments, safety becomes a major concern. Conventional robots, although reliable and consistent, can cause injury to anyone within its range of motion. Soft robotics, wherein systems are made to be soft and mechanically compliant, are thus a promising alternative due to their lightweight nature and ability to cushion impacts, but current designs often sacrifice accuracy and usefulness for safety. We, therefore, have developed a bioinspired robotic arm combining elements of rigid and soft robotics such that it exhibits the positive qualities of both, namely compliance and accuracy, while maintaining a low weight. This article describes the design of a robotic arm-wrist-hand system with seven degrees of freedom (DOFs). The shoulder and elbow each has two DOFs for two perpendicular rotational motions on each joint, and the hand has two DOFs for wrist rotations and one DOF for a grasp motion. The arm is pneumatically powered using custom-built McKibben type pneumatic artificial muscles, which are inflated and deflated using binary and proportional valves. The wrist and hand motions are actuated through servomotors. In addition to the actuators, the arm is equipped with a potentiometer in each joint for detecting joint angle changes. Simulation and experimental results for closed-loop position control are also presented in the article.

Brain Regions Associated to a Kinesthetic Illusion Evoked by Watching a Video of One's Own Moving Hand

PubMed Central

Kaneko, Fuminari; Blanchard, Caroline; Lebar, Nicolas; Nazarian, Bruno; Kavounoudias, Anne; Romaiguère, Patricia

2015-01-01

It is well known that kinesthetic illusions can be induced by stimulation of several sensory systems (proprioception, touch, vision…). In this study we investigated the cerebral network underlying a kinesthetic illusion induced by visual stimulation by using functional magnetic resonance imaging (fMRI) in humans. Participants were instructed to keep their hand still while watching the video of their own moving hand (Self Hand) or that of someone else's moving hand (Other Hand). In the Self Hand condition they experienced an illusory sensation that their hand was moving whereas the Other Hand condition did not induce any kinesthetic illusion. The contrast between the Self Hand and Other Hand conditions showed significant activation in the left dorsal and ventral premotor cortices, in the left Superior and Inferior Parietal lobules, at the right Occipito-Temporal junction as well as in bilateral Insula and Putamen. Most strikingly, there was no activation in the primary motor and somatosensory cortices, whilst previous studies have reported significant activation in these regions for vibration-induced kinesthetic illusions. To our knowledge, this is the first study that indicates that humans can experience kinesthetic perception without activation in the primary motor and somatosensory areas. We conclude that under some conditions watching a video of one's own moving hand could lead to activation of a network that is usually involved in processing copies of efference, thus leading to the illusory perception that the real hand is indeed moving. PMID:26287488

Brain Regions Associated to a Kinesthetic Illusion Evoked by Watching a Video of One's Own Moving Hand.

PubMed

Kaneko, Fuminari; Blanchard, Caroline; Lebar, Nicolas; Nazarian, Bruno; Kavounoudias, Anne; Romaiguère, Patricia

2015-01-01

It is well known that kinesthetic illusions can be induced by stimulation of several sensory systems (proprioception, touch, vision…). In this study we investigated the cerebral network underlying a kinesthetic illusion induced by visual stimulation by using functional magnetic resonance imaging (fMRI) in humans. Participants were instructed to keep their hand still while watching the video of their own moving hand (Self Hand) or that of someone else's moving hand (Other Hand). In the Self Hand condition they experienced an illusory sensation that their hand was moving whereas the Other Hand condition did not induce any kinesthetic illusion. The contrast between the Self Hand and Other Hand conditions showed significant activation in the left dorsal and ventral premotor cortices, in the left Superior and Inferior Parietal lobules, at the right Occipito-Temporal junction as well as in bilateral Insula and Putamen. Most strikingly, there was no activation in the primary motor and somatosensory cortices, whilst previous studies have reported significant activation in these regions for vibration-induced kinesthetic illusions. To our knowledge, this is the first study that indicates that humans can experience kinesthetic perception without activation in the primary motor and somatosensory areas. We conclude that under some conditions watching a video of one's own moving hand could lead to activation of a network that is usually involved in processing copies of efference, thus leading to the illusory perception that the real hand is indeed moving.

Cerebral lateralization of praxis in right- and left-handedness: same pattern, different strength.

PubMed

Vingerhoets, Guy; Acke, Frederic; Alderweireldt, Ann-Sofie; Nys, Jo; Vandemaele, Pieter; Achten, Eric

2012-04-01

We aimed to investigate the effect of hand effector and handedness on the cerebral lateralization of pantomiming learned movements. Fourteen right-handed and 14 left-handed volunteers performed unimanual and bimanual tool-use pantomimes with their dominant or nondominant hand during fMRI. A left hemispheric lateralization was observed in the right- and left-handed group regardless of which hand(s) performed the task. Asymmetry was most marked in the dorsolateral prefrontal cortex (DLPFC), premotor cortex (PMC), and superior and inferior parietal lobules (SPL and IPL). Unimanual pantomimes did not reveal any significant differences in asymmetric cerebral activation patterns between left- and right-handers. Bimanual pantomimes showed increased left premotor and posterior parietal activation in left- and right-handers. Lateralization indices (LI) of the 10% most active voxels in DLPFC, PMC, SPL, and IPL were calculated for each individual in a contrast that compared all tool versus all control conditions. Left-handers showed a significantly reduced overall LI compared with right-handers. This was mainly due to diminished asymmetry in the IPL and SPL. We conclude that the recollection and pantomiming of learned gestures recruits a similar left lateralized activation pattern in right and left-handed individuals. Handedness only influences the strength (not the side) of the lateralization, with left-handers showing a reduced degree of asymmetry that is most readily observed over the posterior parietal region. Together with similar findings in language and visual processing, these results point to a lesser hemispheric specialization in left-handers that may be considered in the cost/benefit assessment to explain the disproportionate handedness polymorphism in humans. Copyright © 2011 Wiley Periodicals, Inc.

Mild cognitive impairment: loss of linguistic task-induced changes in motor cortex excitability.

PubMed

Bracco, L; Giovannelli, F; Bessi, V; Borgheresi, A; Di Tullio, A; Sorbi, S; Zaccara, G; Cincotta, M

2009-03-10

In amnestic mild cognitive impairment (aMCI), functional neuronal connectivity may be altered, as suggested by quantitative EEG and neuroimaging data. In young healthy humans, the execution of linguistic tasks modifies the excitability of the hand area of the dominant primary motor cortex (M1(hand)), as tested by transcranial magnetic stimulation (TMS). We used TMS to investigate functional connectivity between language-related cortical areas and M1(hand) in aMCI. Ten elderly women with aMCI and 10 age-matched women were recruited. All participants were right handed and underwent a neuropsychological evaluation. In the first TMS experiment, participants performed three different tasks: reading aloud, viewing of non-letter strings (baseline), and nonverbal oral movements. The second experiment included the baseline condition and three visual searching/matching tasks using letters, geometric shapes, or digits as target stimuli. In controls, motor evoked potentials (MEP) elicited by suprathreshold TMS of the left M1(hand) were significantly larger during reading aloud (170% baseline) than during nonverbal oral movements, whereas no difference was seen for right M1(hand) stimulation. Similarly, MEP elicited by left M1(hand) stimulation during letter and shape searching/matching tasks were significantly larger compared to digit task. In contrast, linguistic task performance did not produce any significant MEP modulation in patients with aMCI, although neuropsychological evaluation showed normal language abilities. Findings suggest that functional connectivity between the language-related brain regions and the dominant M1(hand) may be altered in amnestic mild cognitive impairment. Follow-up studies will reveal whether transcranial magnetic stimulation application during linguistic tasks may contribute to characterize the risk of conversion to Alzheimer disease.

Human-Human Interaction Forces and Interlimb Coordination During Side-by-Side Walking With Hand Contact.

PubMed

Sylos-Labini, Francesca; d'Avella, Andrea; Lacquaniti, Francesco; Ivanenko, Yury

2018-01-01

Handholding can naturally occur between two walkers. When people walk side-by-side, either with or without hand contact, they often synchronize their steps. However, despite the importance of haptic interaction in general and the natural use of hand contact between humans during walking, few studies have investigated forces arising from physical interactions. Eight pairs of adult subjects participated in this study. They walked on side-by-side treadmills at 4 km/h independently and with hand contact. Only hand contact-related sensory information was available for unintentional synchronization, while visual and auditory communication was obstructed. Subjects walked at their natural cadences or following a metronome. Limb kinematics, hand contact 3D interaction forces and EMG activity of 12 upper limb muscles were recorded. Overall, unintentional step frequency locking was observed during about 40% of time in 88% of pairs walking with hand contact. On average, the amplitude of contact arm oscillations decreased while the contralateral (free) arm oscillated in the same way as during normal walking. Interestingly, EMG activity of the shoulder muscles of the contact arm did not decrease, and their synergistic pattern remained similar. The amplitude of interaction forces and of trunk oscillations was similar for synchronized and non-synchronized steps, though the synchronized steps were characterized by significantly more regular orientations of interaction forces. Our results further support the notion that gait synchronization during natural walking is common, and that it may occur through interaction forces. Conservation of the proximal muscle activity of the contact (not oscillating) arm is consistent with neural coupling between cervical and lumbosacral pattern generation circuitries ("quadrupedal" arm-leg coordination) during human gait. Overall, the findings suggest that individuals might integrate force interaction cues to communicate and coordinate steps during walking.

Human-Human Interaction Forces and Interlimb Coordination During Side-by-Side Walking With Hand Contact

PubMed Central

Sylos-Labini, Francesca; d'Avella, Andrea; Lacquaniti, Francesco; Ivanenko, Yury

2018-01-01

Handholding can naturally occur between two walkers. When people walk side-by-side, either with or without hand contact, they often synchronize their steps. However, despite the importance of haptic interaction in general and the natural use of hand contact between humans during walking, few studies have investigated forces arising from physical interactions. Eight pairs of adult subjects participated in this study. They walked on side-by-side treadmills at 4 km/h independently and with hand contact. Only hand contact-related sensory information was available for unintentional synchronization, while visual and auditory communication was obstructed. Subjects walked at their natural cadences or following a metronome. Limb kinematics, hand contact 3D interaction forces and EMG activity of 12 upper limb muscles were recorded. Overall, unintentional step frequency locking was observed during about 40% of time in 88% of pairs walking with hand contact. On average, the amplitude of contact arm oscillations decreased while the contralateral (free) arm oscillated in the same way as during normal walking. Interestingly, EMG activity of the shoulder muscles of the contact arm did not decrease, and their synergistic pattern remained similar. The amplitude of interaction forces and of trunk oscillations was similar for synchronized and non-synchronized steps, though the synchronized steps were characterized by significantly more regular orientations of interaction forces. Our results further support the notion that gait synchronization during natural walking is common, and that it may occur through interaction forces. Conservation of the proximal muscle activity of the contact (not oscillating) arm is consistent with neural coupling between cervical and lumbosacral pattern generation circuitries (“quadrupedal” arm-leg coordination) during human gait. Overall, the findings suggest that individuals might integrate force interaction cues to communicate and coordinate steps during walking. PMID:29563883

Using subject-specific three-dimensional (3D) anthropometry data in digital human modelling: case study in hand motion simulation.

PubMed

Tsao, Liuxing; Ma, Liang

2016-11-01

Digital human modelling enables ergonomists and designers to consider ergonomic concerns and design alternatives in a timely and cost-efficient manner in the early stages of design. However, the reliability of the simulation could be limited due to the percentile-based approach used in constructing the digital human model. To enhance the accuracy of the size and shape of the models, we proposed a framework to generate digital human models using three-dimensional (3D) anthropometric data. The 3D scan data from specific subjects' hands were segmented based on the estimated centres of rotation. The segments were then driven in forward kinematics to perform several functional postures. The constructed hand models were then verified, thereby validating the feasibility of the framework. The proposed framework helps generate accurate subject-specific digital human models, which can be utilised to guide product design and workspace arrangement. Practitioner Summary: Subject-specific digital human models can be constructed under the proposed framework based on three-dimensional (3D) anthropometry. This approach enables more reliable digital human simulation to guide product design and workspace arrangement.

Finger tracking for hand-held device interface using profile-matching stereo vision

NASA Astrophysics Data System (ADS)

Chang, Yung-Ping; Lee, Dah-Jye; Moore, Jason; Desai, Alok; Tippetts, Beau

2013-01-01

Hundreds of millions of people use hand-held devices frequently and control them by touching the screen with their fingers. If this method of operation is being used by people who are driving, the probability of deaths and accidents occurring substantially increases. With a non-contact control interface, people do not need to touch the screen. As a result, people will not need to pay as much attention to their phones and thus drive more safely than they would otherwise. This interface can be achieved with real-time stereovision. A novel Intensity Profile Shape-Matching Algorithm is able to obtain 3-D information from a pair of stereo images in real time. While this algorithm does have a trade-off between accuracy and processing speed, the result of this algorithm proves the accuracy is sufficient for the practical use of recognizing human poses and finger movement tracking. By choosing an interval of disparity, an object at a certain distance range can be segmented. In other words, we detect the object by its distance to the cameras. The advantage of this profile shape-matching algorithm is that detection of correspondences relies on the shape of profile and not on intensity values, which are subjected to lighting variations. Based on the resulting 3-D information, the movement of fingers in space from a specific distance can be determined. Finger location and movement can then be analyzed for non-contact control of hand-held devices.

Interaction Between the Environment and Animals in Urban Settings: Integrated and Participatory Planning

NASA Astrophysics Data System (ADS)

Tarsitano, Elvira

2006-11-01

In urban ecosystems, the ecological system has become completely unbalanced; this, in turn, has led to an increase in well-known problems such as air pollution, ground pollution, and water pollution. This imbalance has also led to the growth and spread of pathogens harmful to man, animals, and plants. Urban sustainability indicators, both global and local, also “indicate” the percentage of population, but these refer only to the human population, not the animal population. Cities need good waste, water, and air management, effective traffic planning, and good zoning of businesses, crafts, and services; over and above these activities, cities also need for planning to take into account the existence of pets (dogs, cats, and etc.) and nonpet animals (insects, birds, mice, etc.). Cities tend to be designed around humans and “on a human scale,” without taking into account the fact that a huge animal population is living side by side with people. That explains why overcrowding tends to go hand in hand with urbanization; all these populations, including humans, need to adapt to new spaces and often need to drastically change their behavior. This is a fact that must be included when drafting sustainable city plans. The supposed strategy is that of “integrated-participatory” control of the interactions between the environment and animals in the cities. Strategy will focus on the development of integrated approaches and tools for environment and animal management in the context of urban settings. This will require such specific methods as ecological balance sheets and ecoplans for the planning, management, and control of the interrelation among environment, animal, and public health. The objective is to develop a better understanding of urban biodiversity and of urban ecosystem functioning, in order to understand and minimize the negative impacts of human activities on them. The research will focus on assessing and forecasting changes in urban biodiversity, structure, function, and dynamics of urban ecosystems, with relationships among society, economy, biodiversity, and habitats.

Risk factors, perceptions and practices associated with Taenia solium cysticercosis and its control in the smallholder pig production systems in Uganda: a cross-sectional survey.

PubMed

Kungu, Joseph M; Dione, Michel M; Ejobi, Francis; Ocaido, Michael; Grace, Delia

2017-01-03

Prevalence studies report Taenia solium cysticercosis in pig and human populations in Uganda. However, the factors influencing occurrence in smallholder pig production systems are not well documented and little is known about farmers' perceptions of T. solium cysticercosis or farmer practices that could reduce transmission. To determine the risk factors, perceptions and practices regarding T. solium cysticercosis, a household survey using a semi-structured questionnaire was conducted in 1185 households in the rural and urban pig production systems in Masaka, Mukono and Kamuli Districts. Logistic regression was used to measure associations of risk factors with infection. Performance scores were calculated to summarise perceptions and practices of farmers regarding taeniosis, human cysticercosis and porcine cysticercosis as well as farmer behavior related to control or breaking transmission. Pig breed type, farmers' knowledge about transmission, sources of water used, and pig keeping homes where family members were unable to use the latrine were all significantly associated with T. solium cysticercosis in pigs. Performance scores indicated that farmers were more aware of taeniosis (63.0%; 95% Confidence Interval 60.0-65.8) than human or porcine cysticercosis; only three farmers (0.3%, 95% CI = 0.1-0.8) had knowledge on all three conditions. More farmers reported that they dewormed pigs (94.1%) than reported deworming themselves and their family members (62.0%). Albendazole was the most commonly used drug for deworming both pigs and humans (85.0 and 81.5% respectively). Just over half (54.6%) of the farmers interviewed had clean water near the latrines for washing hands. Of these, only 41.9% used water with soap to wash hands after latrine use. Factors that significantly influenced occurrence of T. solium cysticercosis in pigs were identified. Farmers had some knowledge about the disease but did not link taeniosis, human cysticercosis, and porcine cysticercosis. Therefore, there is need to employ strategies that raise awareness and interrupt transmission.

Eye-Hand Coordination during Visuomotor Adaptation with Different Rotation Angles

PubMed Central

Rentsch, Sebastian; Rand, Miya K.

2014-01-01

This study examined adaptive changes of eye-hand coordination during a visuomotor rotation task. Young adults made aiming movements to targets on a horizontal plane, while looking at the rotated feedback (cursor) of hand movements on a monitor. To vary the task difficulty, three rotation angles (30°, 75°, and 150°) were tested in three groups. All groups shortened hand movement time and trajectory length with practice. However, control strategies used were different among groups. The 30° group used proportionately more implicit adjustments of hand movements than other groups. The 75° group used more on-line feedback control, whereas the 150° group used explicit strategic adjustments. Regarding eye-hand coordination, timing of gaze shift to the target was gradually changed with practice from the late to early phase of hand movements in all groups, indicating an emerging gaze-anchoring behavior. Gaze locations prior to the gaze anchoring were also modified with practice from the cursor vicinity to an area between the starting position and the target. Reflecting various task difficulties, these changes occurred fastest in the 30° group, followed by the 75° group. The 150° group persisted in gazing at the cursor vicinity. These results suggest that the function of gaze control during visuomotor adaptation changes from a reactive control for exploring the relation between cursor and hand movements to a predictive control for guiding the hand to the task goal. That gaze-anchoring behavior emerged in all groups despite various control strategies indicates a generality of this adaptive pattern for eye-hand coordination in goal-directed actions. PMID:25333942

An EMG Interface for the Control of Motion and Compliance of a Supernumerary Robotic Finger

PubMed Central

Hussain, Irfan; Spagnoletti, Giovanni; Salvietti, Gionata; Prattichizzo, Domenico

2016-01-01

In this paper, we propose a novel electromyographic (EMG) control interface to control motion and joints compliance of a supernumerary robotic finger. The supernumerary robotic fingers are a recently introduced class of wearable robotics that provides users additional robotic limbs in order to compensate or augment the existing abilities of natural limbs without substituting them. Since supernumerary robotic fingers are supposed to closely interact and perform actions in synergy with the human limbs, the control principles of extra finger should have similar behavior as human’s ones including the ability of regulating the compliance. So that, it is important to propose a control interface and to consider the actuators and sensing capabilities of the robotic extra finger compatible to implement stiffness regulation control techniques. We propose EMG interface and a control approach to regulate the compliance of the device through servo actuators. In particular, we use a commercial EMG armband for gesture recognition to be associated with the motion control of the robotic device and surface one channel EMG electrodes interface to regulate the compliance of the robotic device. We also present an updated version of a robotic extra finger where the adduction/abduction motion is realized through ball bearing and spur gears mechanism. We have validated the proposed interface with two sets of experiments related to compensation and augmentation. In the first set of experiments, different bimanual tasks have been performed with the help of the robotic device and simulating a paretic hand since this novel wearable system can be used to compensate the missing grasping abilities in chronic stroke patients. In the second set, the robotic extra finger is used to enlarge the workspace and manipulation capability of healthy hands. In both sets, the same EMG control interface has been used. The obtained results demonstrate that the proposed control interface is intuitive and can successfully be used, not only to control the motion of a supernumerary robotic finger but also to regulate its compliance. The proposed approach can be exploited also for the control of different wearable devices that has to actively cooperate with the human limbs. PMID:27891088

Monochromatic computed microtomography using laboratory and synchrotron sources and X-ray fluorescence analysis for comprehensive analysis of structural changes in bones.

PubMed

Buzmakov, Alexey; Chukalina, Marina; Nikolaev, Dmitry; Gulimova, Victoriya; Saveliev, Sergey; Tereschenko, Elena; Seregin, Alexey; Senin, Roman; Zolotov, Denis; Prun, Victor; Shaefer, Gerald; Asadchikov, Victor

2015-06-01

A combination of X-ray tomography at different wavelengths and X-ray fluorescence analysis was applied in the study of two types of bone tissue changes: prolonged presence in microgravity conditions and age-related bone growth. The proximal tail vertebrae of geckos were selected for investigation because they do not bear the supporting load in locomotion, which allows them to be considered as an independent indicator of gravitational influence. For the vertebrae of geckos no significant differences were revealed in the elemental composition of the flight samples and the synchronous control samples. In addition, the gecko bone tissue samples from the jaw apparatus, spine and shoulder girdle were measured. The dynamics of structural changes in the bone tissue growth was studied using samples of a human fetal hand. The hands of human fetuses of 11-15 weeks were studied. Autonomous zones of calcium accumulation were found not only in individual fingers but in each of the investigated phalanges. The results obtained are discussed.

Monochromatic computed microtomography using laboratory and synchrotron sources and X-ray fluorescence analysis for comprehensive analysis of structural changes in bones1

PubMed Central

Buzmakov, Alexey; Chukalina, Marina; Nikolaev, Dmitry; Gulimova, Victoriya; Saveliev, Sergey; Tereschenko, Elena; Seregin, Alexey; Senin, Roman; Zolotov, Denis; Prun, Victor; Shaefer, Gerald; Asadchikov, Victor

2015-01-01

A combination of X-ray tomography at different wavelengths and X-ray fluorescence analysis was applied in the study of two types of bone tissue changes: prolonged presence in microgravity conditions and age-related bone growth. The proximal tail vertebrae of geckos were selected for investigation because they do not bear the supporting load in locomotion, which allows them to be considered as an independent indicator of gravitational influence. For the vertebrae of geckos no significant differences were revealed in the elemental composition of the flight samples and the synchronous control samples. In addition, the gecko bone tissue samples from the jaw apparatus, spine and shoulder girdle were measured. The dynamics of structural changes in the bone tissue growth was studied using samples of a human fetal hand. The hands of human fetuses of 11–15 weeks were studied. Autonomous zones of calcium accumulation were found not only in individual fingers but in each of the investigated phalanges. The results obtained are discussed. PMID:26089762

Roles of autophagy in controlling stem cell identity: a perspective of self-renewal and differentiation.

PubMed

Sotthibundhu, Areechun; Promjuntuek, Wilasinee; Liu, Min; Shen, Sanbing; Noisa, Parinya

2018-04-25

Autophagy is crucial for the removal of dysfunctional organelles and protein aggregates and for maintaining stem cell homeostasis, which includes self-renewal, cell differentiation and somatic reprogramming. Loss of self-renewal capacity and pluripotency is a major obstacle to stem cell-based therapies. It has been reported that autophagy regulates stem cells under biological stimuli, starvation, hypoxia, generation of reactive oxygen species (ROS) and cellular senescence. On the one hand, autophagy is shown to play roles in self-renewal by co-function with the ubiquitin-proteasome system (UPS) to promote pluripotency-associated proteins (NANOG, OCT4 and SOX2) in human embryonic stem cells (hESCs). On the other hand, autophagy activity acts as cell reprogramming processes that play an important role for clearance fate determination and upregulates neural and cardiac differentiation. Deregulation of autophagy triggers protein disorders such as neurodegenerative cardiac/muscle diseases and cancer. Therefore, understanding of the roles of the autophagy in stem cell renewal and differentiation may benefit therapeutic development for a range of human diseases.

Preventing healthcare-associated infections through human factors engineering.

PubMed

Jacob, Jesse T; Herwaldt, Loreen A; Durso, Francis T

2018-05-24

Human factors engineering (HFE) approaches are increasingly being used in healthcare, but have been applied in relatively limited ways to infection prevention and control (IPC). Previous studies have focused on using selected HFE tools, but newer literature supports a system-based HFE approach to IPC. Cross-contamination and the existence of workarounds suggest that healthcare workers need better support to reduce and simplify steps in delivering care. Simplifying workflow can lead to better understanding of why a process fails and allow for improvements to reduce errors and increase efficiency. Hand hygiene can be improved using visual cues and nudges based on room layout. Using personal protective equipment appropriately appears simple, but exists in a complex interaction with workload, behavior, emotion, and environmental variables including product placement. HFE can help prevent the pathogen transmission through improving environmental cleaning and appropriate use of medical devices. Emerging evidence suggests that HFE can be applied in IPC to reduce healthcare-associated infections. HFE and IPC collaboration can help improve many of the basic best practices including use of hand hygiene and personal protective equipment by healthcare workers during patient care.

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

PubMed

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.

Manual lateralization in macaques: handedness, target laterality and task complexity.

PubMed

Regaiolli, Barbara; Spiezio, Caterina; Vallortigara, Giorgio

2016-01-01

Non-human primates represent models to understand the evolution of handedness in humans. Despite several researches have been investigating non-human primates handedness, few studies examined the relationship between target position, hand preference and task complexity. This study aimed at investigating macaque handedness in relation to target laterality and tastiness, as well as task complexity. Seven pig-tailed macaques (Macaca nemestrina) were involved in three different "two alternative choice" tests: one low-level task and two high-level tasks (HLTs). During the first and the third tests macaques could select a preferred food and a non-preferred food, whereas by modifying the design of the second test, macaques were presented with no-difference alternative per trial. Furthermore, a simple-reaching test was administered to assess hand preference in a social context. Macaques showed hand preference at individual level both in simple and complex tasks, but not in the simple-reaching test. Moreover, target position seemed to affect hand preference in retrieving an object in the low-level task, but not in the HLT. Additionally, individual hand preference seemed to be affected from the tastiness of the item to be retrieved. The results suggest that both target laterality and individual motivation might influence hand preference of macaques, especially in simple tasks.

49 CFR 236.207 - Electric lock on hand-operated switch; control.

Code of Federal Regulations, 2011 CFR

2011-10-01

... THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Block Signal Systems Standards § 236.207 Electric lock on hand-operated... 49 Transportation 4 2011-10-01 2011-10-01 false Electric lock on hand-operated switch; control...

Telerobotic control of a dextrous manipulator using master and six-DOF hand-controllers for space assembly and servicing tasks

NASA Technical Reports Server (NTRS)

O'Hara, John M.

1987-01-01

Two studies were conducted evaluating methods of controlling a telerobot; bilateral force reflecting master controllers and proportional rate six degrees of freedom (DOF) hand controllers. The first study compared the controllers on performance of single manipulator arm tasks, a peg-in-the-hole task, and simulated satellite orbital replacement unit changeout. The second study, a Space Station truss assembly task, required simultaneous operation of both manipulator arms (all 12 DOFs) and complex multiaxis slave arm movements. Task times were significantly longer and fewer errors were committed with the hand controllers. The hand controllers were also rated significantly higher in cognitive and manual control workload on the two-arm task. The master controllers were rated significantly higher in physical workload. There were no significant differences in ratings of manipulator control quality.

Noninvasive near-infrared topography of human brain activity using intensity modulation spectroscopy

NASA Astrophysics Data System (ADS)

Yamashita, Yuichi; Maki, Atsushi; Ito, Yoshitoshi; Watanabe, Eiju; Mayanagi, Yoshiaki; Koizumi, Hideaki

1996-04-01

We describe the functional topography of human brain activity due to motor stimulation by using near-infrared spectroscopy. Finger motion by each hand was used as the motor stimulation, and activity in the left fronto-central region of the brain was measured. A greater change in oxyhemoglobin concentration due to brain activity during the stimulation was obtained for the right hand than for the left hand. Localization of the activity was obtained by topographically mapping the measured changes for ten positions within the region.

Factors influencing hand washing behaviour in primary schools: process evaluation within a randomised controlled trial

PubMed Central

Chittleborough, Catherine R.; Nicholson, Alexandra L.; Basker, Elaine; Bell, Sarah; Campbell, Rona

2013-01-01

This paper explores factors that may influence hand washing behaviour among pupils and staff in primary schools. A qualitative process evaluation within a cluster randomised controlled trial included pupil focus groups (n=16, ages 6 to 11, semi-structured interviews (n=16 teachers) and observations of hand washing facilities (n=57). Pupils and staff in intervention and control schools demonstrated a similar level of understanding of how, when and why they should wash their hands. Lack of time, poor adult modelling of regular hand washing and unattractive facilities were seen as important barriers to regular hand washing. Reminders and explanations for the importance of hand hygiene were thought to have a positive impact. Influencing individual choices about hand washing through education and information may be necessary, but not sufficient, for initiating and maintaining good hand washing practices. Structural factors, including having time to wash hands using accessible, clean facilities, and being encouraged through the existence of hand washing opportunities in the daily routine and hand washing being viewed as the social norm, will also influence hand washing behaviour. The effectiveness of educational interventions at improving hand hygiene in primary schools may be improved by changing priorities of staff and increasing accessibility to quality facilities. PMID:22623617

Factors influencing hand washing behaviour in primary schools: process evaluation within a randomized controlled trial.

PubMed

Chittleborough, Catherine R; Nicholson, Alexandra L; Basker, Elaine; Bell, Sarah; Campbell, Rona

2012-12-01

This article explores factors that may influence hand washing behaviour among pupils and staff in primary schools. A qualitative process evaluation within a cluster randomized controlled trial included pupil focus groups (n = 16, aged 6-11 years), semi-structured interviews (n = 16 teachers) and observations of hand washing facilities (n = 57). Pupils and staff in intervention and control schools demonstrated a similar level of understanding of how, when and why they should wash their hands. Lack of time, poor adult modelling of regular hand washing and unattractive facilities were seen as important barriers to regular hand washing. Reminders and explanations for the importance of hand hygiene were thought to have a positive impact. Influencing individual choices about hand washing through education and information may be necessary, but not sufficient, for initiating and maintaining good hand washing practices. Structural factors, including having time to wash hands using accessible, clean facilities, and being encouraged through the existence of hand washing opportunities in the daily routine and hand washing being viewed as the social norm, will also influence hand washing behaviour. The effectiveness of educational interventions at improving hand hygiene in primary schools may be improved by changing priorities of staff and increasing accessibility to quality facilities.

Effect of gender and hand laterality on pain processing in human neonates.

PubMed

Ozawa, Mio; Kanda, Katsuya; Hirata, Michio; Kusakawa, Isao; Suzuki, Chieko

2011-01-01

Previous studies in adults have reported that handedness and gender can affect pain perception. However, it is currently unclear when these differences emerge in human development. Therefore, we examined prefrontal responses to pain stimulation among newborns during their first acute pain experience after birth. Forty newborns at 4-6 days postnatal age were observed during clinically required blood sampling while prefrontal activation was measured with near infrared spectroscopy. Blood sampling in this study was the first experience of a procedure involving skin breaking for these infants. We divided subjects into a right-hand stimulation group (n=21) and a left-hand stimulation group (n=19), depending on whether blood was sampled from the right or the left hand. A three-way analysis of variance (ANOVA) was conducted to examine the effects of several variables on the magnitude of the oxy-Hb value in response to pain stimulus, including stimulus side (right hand or left hand), gender (male or female), recording side (right prefrontal area or left prefrontal area) and interactions between these variables. The data revealed a significant effect of stimulus side (F (1, 72)=9.892, P=0.002), showing that the right-hand stimulation induced a greater prefrontal activation than the left-hand stimulation. No significant gender difference or interactions were found. Our findings suggest that hand laterality affects pain perception even in neonates. However, gender differences in pain perception did not appear to occur during the neonatal period. Further investigations using brain-imaging techniques are required to identify laterality- or gender-related differences in pain processing in humans. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Grasp with hand and mouth: a kinematic study on healthy subjects.

PubMed

Gentilucci, M; Benuzzi, F; Gangitano, M; Grimaldi, S

2001-10-01

Neurons involved in grasp preparation with hand and mouth were previously recorded in the premotor cortex of monkey. The aim of the present kinematic study was to determine whether a unique planning underlies the act of grasping with hand and mouth in humans as well. In a set of four experiments, healthy subjects reached and grasped with the hand an object of different size while opening the mouth (experiments 1 and 3), or extending the other forearm (experiment 4), or the fingers of the other hand (experiment 5). In a subsequent set of three experiments, subjects grasped an object of different size with the mouth, while opening the fingers of the right hand (experiments 6-8). The initial kinematics of mouth and finger opening, but not of forearm extension, was affected by the size of the grasped object congruently with the size effect on initial grasp kinematics. This effect was due neither to visual presentation of the object, without the successive grasp motor act (experiment 2) nor to synchronism between finger and mouth opening (experiments 3, 7, and 8). In experiment 9 subjects grasped with the right hand an object of different size while pronouncing a syllable printed on the target. Mouth opening and sound production were affected by the grasped object size. The results of the present study are discussed according to the notion that in an action each motor act is prepared before the beginning of the motor sequence. Double grasp preparation can be used for successive motor acts on the same object as, for example, grasping food with the hand and ingesting it after bringing it to the mouth. We speculate that the circuits involved in double grasp preparation might have been the neural substrate where hand motor patterns used as primitive communication signs were transferred to mouth articulation system. This is in accordance with the hypothesis that Broca's area derives phylogenetically from the monkey premotor area where hand movements are controlled.

[Effects of aroma hand massage on pain, state anxiety and depression in hospice patients with terminal cancer].

PubMed

Chang, So Young

2008-08-01

The purpose of this study was to examine the effects of aroma hand massage on pain, state anxiety and depression in hospice patients with terminal cancer. This study was a nonequivalent control group pretest-posttest design. The subjects were 58 hospice patients with terminal cancer who were hospitalized. Twenty eight hospice patients with terminal cancer were assigned to the experimental group (aroma hand massage), and 30 hospice patients with terminal cancer were assigned to the control group (general oil hand massage). As for the experimental treatment, the experimental group went through aroma hand massage on each hand for 5 min for 7 days with blended oil-a mixture of Bergamot, Lavender, and Frankincense in the ratio of 1:1:1, which was diluted 1.5% with sweet almond carrier oil 50 ml. The control group went through general oil hand massage by only sweet almond carrier oil-on each hand for 5 min for 7 days. The aroma hand massage experimental group showed more significant differences in the changes of pain score (t=-3.52, p=.001) and depression (t=-8.99, p=.000) than the control group. Aroma hand massage had a positive effect on pain and depression in hospice patients with terminal cancer.

Angiotensin II type 1 receptor blockade does not enhance apoptotic cell death during ischemia and reperfusion in humans in vivo.

PubMed

Meijer, Patrick; Wouters, Constantijn W; Oyen, Wim J; Boerman, Otto C; Scheffer, Gert Jan; Smits, Paul; Rongen, Gerard A

2011-06-01

Despite the theoretical benefits, angiotensin II type 1 receptor antagonists seem to enhance rather than reduce morbidity and mortality after myocardial infarction compared with angiotensin-converting enzyme inhibitors. This may result from unopposed angiotensin II type 2 receptor stimulation, which is associated with enhanced apoptotic cell death and increased infarct size. We studied whether the clinical effectiveness of irbesartan is hampered by enhanced apoptotic activity, detected by exposition of phosphatidylserines, during ischemia and reperfusion in humans in vivo. Twenty healthy male volunteers were randomized to a 1-week treatment with irbesartan (300 mg/d) or placebo in a double-blind fashion. After treatment, all participants underwent 10 minutes of ischemic exercise of the nondominant forearm. Upon reperfusion, Tc-99m-labeled Annexin A5 was administered, and 1 and 4 hours afterward, both hands were scanned using a gamma camera. Targeting of annexin A5, expressed as the percentage difference in radioactivity in the area of interest (thenar muscle) between experimental and control hand, did not differ between participants treated with irbesartan or placebo. Therefore, irbesartan does not enhance phosphatidylserine exposition in humans in vivo. The results of this study do not support enhanced apoptotic activity after treatment with irbesartan in a setting of ischemia and reperfusion.

Do WiFi-based hand hygiene dispenser systems increase hand hygiene compliance?

PubMed

Scheithauer, Simone; Bickenbach, Johannes; Heisel, Hans; Fehling, Patrick; Marx, Gernot; Lemmen, Sebastian

2018-05-17

Innovative methods to ensure better compliance in hand hygiene are urgently needed. The aim of this study was to determine if WiFi-based hand hygiene dispenser-driven self-assessment systems (Wireless Fidelity, WiFi-dispenser) can support the work of infection control teams. Our results suggest that the continuous monitoring of dispenser usage can be a valuable addition to infection prevention and control programs, when used in a bundle in combination with conventional hand hygiene training. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Role of vision in aperture closure control during reach-to-grasp movements.

PubMed

Rand, Miya K; Lemay, Martin; Squire, Linda M; Shimansky, Yury P; Stelmach, George E

2007-08-01

We have previously shown that the distance from the hand to the target at which finger closure is initiated during the reach (aperture closure distance) depends on the amplitude of peak aperture, as well as hand velocity and acceleration. This dependence suggests the existence of a control law according to which a decision to initiate finger closure during the reach is made when the hand distance to target crosses a threshold that is a function of the above movement-related parameters. The present study examined whether the control law is affected by manipulating the visibility of the hand and the target. Young adults made reach-to-grasp movements to a dowel under conditions in which the target or the hand or both were either visible or not visible. Reaching for and grasping a target when the hand and/or target were not visible significantly increased transport time and widened peak aperture. Aperture closure distance was significantly lengthened and wrist peak velocity was decreased only when the target was not visible. Further analysis showed that the control law was significantly different between the visibility-related conditions. When either the hand or target was not visible, the aperture closure distance systematically increased compared to its value for the same amplitude of peak aperture, hand velocity, and acceleration under full visibility. This implies an increase in the distance-related safety margin for grasping when the hand or target is not visible. It has been also found that the same control law can be applied to all conditions, if variables describing hand and target visibility were included in the control law model, as the parameters of the task-related environmental context, in addition to the above movement-related parameters. This suggests that that the CNS utilizes those variables for controlling grasp initiation based on a general control law.

Role of vision in aperture closure control during reach-to-grasp movements

PubMed Central

Rand, Miya K.; Lemay, Martin; Squire, Linda M.; Shimansky, Yury P.; Stelmach, George E.

2007-01-01

We have previously shown that the distance from the hand to the target at which finger closure is initiated during the reach (aperture closure distance) depends on the amplitude of peak aperture, as well as hand velocity and acceleration. This dependence suggests the existence of a control law according to which a decision to initiate finger closure during the reach is made when the hand distance to target crosses a threshold that is a function of the above movement-related parameters. The present study examined whether the control law is affected by manipulating the visibility of the hand and the target. Young adults made reach-to-grasp movements to a dowel under conditions in which the target or the hand or both were either visible or not visible. Reaching for and grasping a target when the hand and/or target were not visible significantly increased transport time and widened peak aperture. Aperture closure distance was significantly lengthened and wrist peak velocity was decreased only when the target was not visible. Further analysis showed that the control law was significantly different between the visibility-related conditions. When either the hand or target was not visible, the aperture closure distance systematically increased compared to its value for the same amplitude of peak aperture, hand velocity, and acceleration under full visibility. This implies an increase in the distance-related safety margin for grasping when the hand or target is not visible. It has been also found that the same control law can be applied to all conditions, if variables describing hand and target visibility were included in the control law model, as the parameters of the task-related environmental context, in addition to the above movement-related parameters. This suggests that that the CNS utilizes those variables for controlling grasp initiation based on a general control law. PMID:17476491

Further Development and Test of an Artificial Hand for Communication with Deaf-Blind People. Final Report.

ERIC Educational Resources Information Center

Laenger, Charles J., Sr.; Peel, H. Herbert

The report details the development and design of a mechanical hand for communicating with deaf blind persons. It is explained that the device, which looks and functions like the human hand, forms the symbols of the one-hand manual alphabet upon command from a standard electric typewriter keyboard. The report addresses the following topics (sample…

Force feedback in a piezoelectric linear actuator for neurosurgery.

PubMed

De Lorenzo, Danilo; De Momi, Elena; Dyagilev, Ilya; Manganelli, Rudy; Formaglio, Alessandro; Prattichizzo, Domenico; Shoham, Moshe; Ferrigno, Giancarlo

2011-09-01

Force feedback in robotic minimally invasive surgery allows the human operator to manipulate tissues as if his/her hands were in contact with the patient organs. A force sensor mounted on the probe raises problems with sterilization of the overall surgical tool. Also, the use of off-axis gauges introduces a moment that increases the friction force on the bearing, which can easily mask off the signal, given the small force to be measured. This work aims at designing and testing two methods for estimating the resistance to the advancement (force) experienced by a standard probe for brain biopsies within a brain-like material. The further goal is to provide a neurosurgeon using a master-slave tele-operated driver with direct feedback on the tissue mechanical characteristics. Two possible sensing methods, in-axis strain gauge force sensor and position-position error (control-based method), were implemented and tested, both aimed at device miniaturization. The analysis carried out was aimed at fulfilment of the psychophysics requirements for force detection and delay tolerance, also taking into account safety, which is directly related to the last two issues. Controller parameters definition is addressed and consideration is given to development of the device with integration of a haptic interface. Results show better performance of the control-based method (RMSE < 0.1 N), which is also best for reliability, sterilizability, and material dimensions for the application addressed. The control-based method developed for force estimation is compatible with the neurosurgical application and is also capable of measuring tissue resistance without any additional sensors. Force feedback in minimally invasive surgery allows the human operator to manipulate tissues as if his/her hands were in contact with the patient organs. Copyright © 2011 John Wiley & Sons, Ltd.

HandTutor™ enhanced hand rehabilitation after stroke--a pilot study.

PubMed

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 < 0.0003. The results from this pilot study support further investigation of the use of the HandTutorTM in combination with traditional occupational therapy and physiotherapy during post stroke hand function rehabilitation.

Beneficial effects of an investigational wristband containing Synsepalum dulcificum (miracle fruit) seed oil on the performance of hand and finger motor skills in healthy subjects: A randomized controlled preliminary study.

PubMed

Gorin, Steven; Wakeford, Charles; Zhang, Guodong; Sukamtoh, Elvira; Matteliano, Charles Joseph; Finch, Alfred Earl

2018-02-01

Miracle fruit (Synsepalum dulcificum) seed oil (MFSO) contains phytochemicals and nutrients reported to affect musculoskeletal performance. The purpose of this study was to assess the safety and efficacy of a compression wristband containing MFSO on its ability to measurably improve the hand and finger motor skills of participants. Healthy right-handed participants (n = 38) were randomized in this double-blind, placebo-controlled study of MFSO and vehicle wristbands. Subjects wore the wristband on their left hand 4-6 weeks and then only on their right hand 2-4 weeks; the contralateral untreated hand served as an additional control. Twelve hand/finger motor skills were measured using quantitative bio-instrumentation tests, and subject self-assessment questionnaires were conducted. With each hand, in 9/12 tests, the MFSO group showed a clinically meaningful average improvement compared with an average worsening in the vehicle group. Statistical superiority to the control treatment group was exhibited in 9/12 tests for each hand (p < .01). After discontinuing the MFSO wristband on the left hand, test values regressed toward baseline levels. Subjects favored the MFSO wristband over the control, rating it as effective in improving their motor skills. Use of the MFSO wristband may improve an individual's manual dexterity skills and ability to maintain this performance. Copyright © 2017 The Authors Phytotherapy Research Published by John Wiley & Sons Ltd.

Neural Network Classifies Teleoperation Data

NASA Technical Reports Server (NTRS)

Fiorini, Paolo; Giancaspro, Antonio; Losito, Sergio; Pasquariello, Guido

1994-01-01

Prototype artificial neural network, implemented in software, identifies phases of telemanipulator tasks in real time by analyzing feedback signals from force sensors on manipulator hand. Prototype is early, subsystem-level product of continuing effort to develop automated system that assists in training and supervising human control operator: provides symbolic feedback (e.g., warnings of impending collisions or evaluations of performance) to operator in real time during successive executions of same task. Also simplifies transition between teleoperation and autonomous modes of telerobotic system.

Kinesthetic coupling between operator and remote manipulator

NASA Technical Reports Server (NTRS)

Bejczy, A. K.; Salisbury, J. K., Jr.

1980-01-01

A universal force-reflecting hand controller has been developed which allows the establishment of a kinesthetic coupling between the operator and a remote manipulator. The six-degree-of-freedom controller was designed to generate forces and torques on its three positional and three rotational axes in order to permit the operator to accurately feel the forces encountered by the manipulator and be as transparent to operate as possible. The universal controller has been used in an application involving a six-degree-of-freedom mechanical arm equipped with a six-dimensional force-torque sensor at its base. In this application, the hand controller acts as a position control input device to the arm, while forces and torques sensed at the base of the mechanical hand back drive the hand controller. The positional control relation and the back driving of the controller according to inputs experienced by the force-torque sensor are established through complex mathematical transformations performed by a minicomputer. The hand controller is intended as a development tool for investigating force-reflecting master-slave manipulator control technology.

Grasping with the Press of a Button: Grasp-selective Responses in the Human Anterior Intraparietal Sulcus Depend on Nonarbitrary Causal Relationships between Hand Movements and End-effector Actions

PubMed Central

Frey, Scott H.; Hansen, Marc; Marchal, Noah

2016-01-01

Evidence implicates ventral parieto-premotor cortices in representing the goal of grasping independent of the movements or effectors involved [Umilta, M. A., Escola, L., Intskirveli, I., Grammont, F., Rochat, M., Caruana, F., et al. When pliers become fingers in the monkey motor system. Proceedings of the National Academy of Sciences, U.S.A., 105, 2209–2213, 2008; Tunik, E., Frey, S. H., & Grafton, S. T. Virtual lesions of the anterior intraparietal area disrupt goal-dependent on-line adjustments of grasp. Nature Neuroscience, 8, 505–511, 2005]. Modern technologies that enable arbitrary causal relationships between hand movements and tool actions provide a strong test of this hypothesis. We capitalized on this unique opportunity by recording activity with fMRI during tasks in which healthy adults performed goal-directed reach and grasp actions manually or by depressing buttons to initiate these same behaviors in a remotely located robotic arm (arbitrary causal relationship). As shown previously [Binkofski, F., Dohle, C., Posse, S., Stephan, K. M., Hefter, H., Seitz, R. J., et al. Human anterior intraparietal area subserves prehension: A combined lesion and functional MRI activation study. Neurology, 50, 1253–1259, 1998], we detected greater activity in the vicinity of the anterior intraparietal sulcus (aIPS) during manual grasp versus reach. In contrast to prior studies involving tools controlled by nonarbitrarily related hand movements [Gallivan, J. P., McLean, D. A., Valyear, K. F., & Culham, J. C. Decoding the neural mechanisms of human tool use. Elife, 2, e00425, 2013; Jacobs, S., Danielmeier, C., & Frey, S. H. Human anterior intraparietal and ventral premotor cortices support representations of grasping with the hand or a novel tool. Journal of Cognitive Neuroscience, 22, 2594–2608, 2010], however, responses within the aIPS and premotor cortex exhibited no evidence of selectivity for grasp when participants employed the robot. Instead, these regions showed comparable increases in activity during both the reach and grasp conditions. Despite equivalent sensorimotor demands, the right cerebellar hemisphere displayed greater activity when participants initiated the robot’s actions versus when they pressed a button known to be nonfunctional and watched the very same actions undertaken autonomously. This supports the hypothesis that the cerebellum predicts the forthcoming sensory consequences of volitional actions [Blakemore, S. J., Frith, C. D., & Wolpert, D. M. The cerebellum is involved in predicting the sensory consequences of action. NeuroReport, 12, 1879–1884, 2001]. We conclude that grasp-selective responses in the human aIPS and premotor cortex depend on the existence of nonarbitrary causal relationships between hand movements and end-effector actions. PMID:25436672

Unexpected factors affecting the excitability of human motoneurones in voluntary and stimulated contractions

PubMed Central

Khan, Serajul I.; Taylor, Janet L.

2016-01-01

Key points The output of human motoneurone pools decreases with fatiguing exercise, but the mechanisms involved are uncertain. We explored depression of recurrent motoneurone discharges (F‐waves) after sustained maximal voluntary contractions (MVCs).MVC depressed the size and frequency of F‐waves in a hand muscle but a submaximal contraction (at 50% MVC) did not.Surprisingly, activation of the motoneurones antidromically by stimulation of the ulnar nerve (at 20 or 40 Hz) did not depress F‐wave area or persistence.Furthermore, a sustained (3 min) MVC of a hand muscle depressed F‐waves in its antagonist but not in a remote hand muscle.Our findings suggest that depression of F‐waves after voluntary contractions is not simply due to repetitive activation of the motoneurones but requires descending voluntary drive.  Furthermore, this effect may depress nearby, but not distant, spinal motoneurone pools. Abstract There are major spinal changes induced by repetitive activity and fatigue that could contribute to ‘central’ fatigue but the mechanisms involved are poorly understood in humans. Here we confirmed that the recurrent motoneuronal discharge (F‐wave) is reduced during relaxation immediately after a sustained maximal voluntary contraction (MVC) of an intrinsic hand muscle (abductor digiti minimi, ADM) and explored the relationship between motoneurone firing and the depression of F‐waves in three ways. First, the depression (in both F‐wave area and F‐wave persistence) was present after a 10 s MVC (initial decrease 36.4 ± 19.1%; mean ± SD) but not after a submaximal voluntary contraction at 50% maximum. Second, to evoke motoneurone discharge without volitional effort, 10 s tetanic contractions were produced by supramaximal ulnar nerve stimulation at the elbow at physiological frequencies of 25 and 40 Hz. Surprisingly, neither produced depression of F‐waves in ADM to test supramaximal stimulation of the ulnar nerve at the wrist. Finally, a sustained MVC (3 min) of the antagonist to ADM (4th palmar interosseous) depressed F‐waves in the anatomically close ADM (20 ± 18.2%) but not in the more remote first dorsal interosseous on the radial side of the hand. We argue that depression of F‐waves after voluntary contractions may not be due to repetitive activation of the motoneurones but requires descending voluntary drive. Furthermore, this effect may depress nearby, but not distant, spinal motoneurone pools and it reveals potentially novel mechanisms controlling the output of human motoneurones. PMID:26940402

Unexpected factors affecting the excitability of human motoneurones in voluntary and stimulated contractions.

PubMed

Khan, Serajul I; Taylor, Janet L; Gandevia, Simon C

2016-05-15

The output of human motoneurone pools decreases with fatiguing exercise, but the mechanisms involved are uncertain. We explored depression of recurrent motoneurone discharges (F-waves) after sustained maximal voluntary contractions (MVCs). MVC depressed the size and frequency of F-waves in a hand muscle but a submaximal contraction (at 50% MVC) did not. Surprisingly, activation of the motoneurones antidromically by stimulation of the ulnar nerve (at 20 or 40 Hz) did not depress F-wave area or persistence. Furthermore, a sustained (3 min) MVC of a hand muscle depressed F-waves in its antagonist but not in a remote hand muscle. Our findings suggest that depression of F-waves after voluntary contractions is not simply due to repetitive activation of the motoneurones but requires descending voluntary drive.  Furthermore, this effect may depress nearby, but not distant, spinal motoneurone pools. There are major spinal changes induced by repetitive activity and fatigue that could contribute to 'central' fatigue but the mechanisms involved are poorly understood in humans. Here we confirmed that the recurrent motoneuronal discharge (F-wave) is reduced during relaxation immediately after a sustained maximal voluntary contraction (MVC) of an intrinsic hand muscle (abductor digiti minimi, ADM) and explored the relationship between motoneurone firing and the depression of F-waves in three ways. First, the depression (in both F-wave area and F-wave persistence) was present after a 10 s MVC (initial decrease 36.4 ± 19.1%; mean ± SD) but not after a submaximal voluntary contraction at 50% maximum. Second, to evoke motoneurone discharge without volitional effort, 10 s tetanic contractions were produced by supramaximal ulnar nerve stimulation at the elbow at physiological frequencies of 25 and 40 Hz. Surprisingly, neither produced depression of F-waves in ADM to test supramaximal stimulation of the ulnar nerve at the wrist. Finally, a sustained MVC (3 min) of the antagonist to ADM (4th palmar interosseous) depressed F-waves in the anatomically close ADM (20 ± 18.2%) but not in the more remote first dorsal interosseous on the radial side of the hand. We argue that depression of F-waves after voluntary contractions may not be due to repetitive activation of the motoneurones but requires descending voluntary drive. Furthermore, this effect may depress nearby, but not distant, spinal motoneurone pools and it reveals potentially novel mechanisms controlling the output of human motoneurones. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Gender differences in the mu rhythm of the human mirror-neuron system.

PubMed

Cheng, Yawei; Lee, Po-Lei; Yang, Chia-Yen; Lin, Ching-Po; Hung, Daisy; Decety, Jean

2008-05-07

Psychologically, females are usually thought to be superior in interpersonal sensitivity than males. The human mirror-neuron system is considered to provide the basic mechanism for social cognition. However, whether the human mirror-neuron system exhibits gender differences is not yet clear. We measured the electroencephalographic mu rhythm, as a reliable indicator of the human mirror-neuron system activity, when female (N = 20) and male (N = 20) participants watched either hand actions or a moving dot. The display of the hand actions included androgynous, male, and female characteristics. The results demonstrate that females displayed significantly stronger mu suppression than males when watching hand actions. Instead, mu suppression was similar across genders when participants observed the moving dot and between the perceived sex differences (same-sex vs. opposite-sex). In addition, the mu suppressions during the observation of hand actions positively correlated with the personal distress subscale of the interpersonal reactivity index and negatively correlated with the systemizing quotient. The present findings indirectly lend support to the extreme male brain theory put forward by Baron-Cohen (2005), and may cast some light on the mirror-neuron dysfunction in autism spectrum disorders. The mu rhythm in the human mirror-neuron system can be a potential biomarker of empathic mimicry.

Myoelectric control of prosthetic hands: state-of-the-art review

PubMed Central

Geethanjali, Purushothaman

2016-01-01

Myoelectric signals (MES) have been used in various applications, in particular, for identification of user intention to potentially control assistive devices for amputees, orthotic devices, and exoskeleton in order to augment capability of the user. MES are also used to estimate force and, hence, torque to actuate the assistive device. The application of MES is not limited to assistive devices, and they also find potential applications in teleoperation of robots, haptic devices, virtual reality, and so on. The myoelectric control-based prosthetic hand aids to restore activities of daily living of amputees in order to improve the self-esteem of the user. All myoelectric control-based prosthetic hands may not have similar operations and exhibit variation in sensing input, deciphering the signals, and actuating prosthetic hand. Researchers are focusing on improving the functionality of prosthetic hand in order to suit the user requirement with the different operating features. The myoelectric control differs in operation to accommodate various external factors. This article reviews the state of the art of myoelectric prosthetic hand, giving description of each control strategy. PMID:27555799

The Impact of Musical Training on Hand Biomechanics in String Musicians.

PubMed

Gorniak, Stacey L; Collins, Evan D; Goldie Staines, Kimberly; Brooks, Forrest A; Young, Ricardo V

2018-04-01

The effects of musical training on the body in professional musicians remain an understudied area, particularly in reference to understanding and managing orthopedic/neuromuscular deviations and injuries in this population. The purpose of this study was to evaluate hand/finger fine motor function in musicians via physical examination as well as laboratory-based evaluations. Thirteen healthy noninjured young elite string musicians participated in this study. Performance of musicians was compared with healthy age-matched, sex-matched, and handedness-matched nonmusician controls. Musicians exhibited decreased intrinsic muscle strength compared with controls; however, no change in extrinsic muscle strength was found between groups. No between-group differences in overall force control were found; however, Group × Hand (right vs left) interactions were found in force control. These data suggest that musicians are a unique population with respect to: (1) fine motor control of the hand; and (2) exhibit changes in differential hand use. This suggests cortical reorganization of string musicians, such that this population should be studied separately from typical healthy controls with respect to hand function.

Accessibility Is the Mother of Invention: When It Comes to an Innovative Hand Control System

ERIC Educational Resources Information Center

Exceptional Parent, 2007

2007-01-01

This article features Sure Grip hand control, an innovative hand control system created by Keith Howell, the President and founder of Howell Ventures LTD. Howell was in his early teens when he experienced an accident that resulted in his quadriplegia. From that point on, Howell set about to manufacture a set of controls that would emulate the…

Shaping of arm configuration space by prescription of non-Euclidean metrics with applications to human motor control

NASA Astrophysics Data System (ADS)

Biess, Armin

2013-01-01

The study of the kinematic and dynamic features of human arm movements provides insights into the computational strategies underlying human motor control. In this paper a differential geometric approach to movement control is taken by endowing arm configuration space with different non-Euclidean metric structures to study the predictions of the generalized minimum-jerk (MJ) model in the resulting Riemannian manifold for different types of human arm movements. For each metric space the solution of the generalized MJ model is given by reparametrized geodesic paths. This geodesic model is applied to a variety of motor tasks ranging from three-dimensional unconstrained movements of a four degree of freedom arm between pointlike targets to constrained movements where the hand location is confined to a surface (e.g., a sphere) or a curve (e.g., an ellipse). For the latter speed-curvature relations are derived depending on the boundary conditions imposed (periodic or nonperiodic) and the compatibility with the empirical one-third power law is shown. Based on these theoretical studies and recent experimental findings, I argue that geodesics may be an emergent property of the motor system and that the sensorimotor system may shape arm configuration space by learning metric structures through sensorimotor feedback.

Integrated control programmes for schistosomiasis and other helminth infections in P.R. China.

PubMed

Xu, Jing; Xu, Jun-Fang; Li, Shi-Zhu; Zhang, Li-Juan; Wang, Qiang; Zhu, Hui-Hui; Zhou, Xiao-Nong

2015-01-01

The prevalence of human schistosomiasis and soil-transmitted helminthiasis (STH) has decreased significantly in the People's Republic of China (P.R. China), particularly after 2005 when the national control programmes were reinforced by forming of integrated control strategies. Furthermore, social-economic development also contributed to the decrease of schistosome and soil-transmitted helminth infections. The prevalence of the zoonotic helminthiasis, including clonorchiasis and echinococcosis, on the other hand, is either underestimated or has in fact increased due to changes in social and environmental factors. In comparison with the control strategies in force and their effects on those four kinds of helminthiasis, the challenges and control priorities for the potential transfer from control to elimination of each disease is reviewed, to provide evidence for policy-makers to act upon. Copyright © 2013 Elsevier B.V. All rights reserved.