scholarly journals Gait control in a soft robot by sensing interactions with the environment using self-deformation

2016 ◽  
Vol 3 (12) ◽  
pp. 160766 ◽  
Author(s):  
Takuya Umedachi ◽  
Takeshi Kano ◽  
Akio Ishiguro ◽  
Barry A. Trimmer
Keyword(s):  
Sensory Feedback ◽  
Soft Tissues ◽  
Sensory Information ◽  
Gait Pattern ◽  
Soft Robot ◽  
Body Parts ◽  
Gait Control ◽  
Mechanical Responses ◽  
Contact Points ◽  
Propagating Waves

All animals use mechanosensors to help them move in complex and changing environments. With few exceptions, these sensors are embedded in soft tissues that deform in normal use such that sensory feedback results from the interaction of an animal with its environment. Useful information about the environment is expected to be embedded in the mechanical responses of the tissues during movements. To explore how such sensory information can be used to control movements, we have developed a soft-bodied crawling robot inspired by a highly tractable animal model, the tobacco hornworm Manduca sexta . This robot uses deformations of its body to detect changes in friction force on a substrate. This information is used to provide local sensory feedback for coupled oscillators that control the robot's locomotion. The validity of the control strategy is demonstrated with both simulation and a highly deformable three-dimensionally printed soft robot. The results show that very simple oscillators are able to generate propagating waves and crawling/inching locomotion through the interplay of deformation in different body parts in a fully decentralized manner. Additionally, we confirmed numerically and experimentally that the gait pattern can switch depending on the surface contact points. These results are expected to help in the design of adaptable, robust locomotion control systems for soft robots and also suggest testable hypotheses about how soft animals use sensory feedback.

scholarly journals The emulation theory of representation: Motor control, imagery, and perception

2004 ◽  
Vol 27 (3) ◽  
pp. 377-396 ◽  
Author(s):  
Rick Grush
Keyword(s):  
Motor Control ◽  
Sensory Feedback ◽  
Sensory Input ◽  
Neural Circuits ◽  
Sensory Information ◽  
The Body ◽  
Feedback Delay ◽  
Run Off ◽  
Effects Of Feedback ◽  
The Brain

The emulation theory of representation is developed and explored as a framework that can revealingly synthesize a wide variety of representational functions of the brain. The framework is based on constructs from control theory (forward models) and signal processing (Kalman filters). The idea is that in addition to simply engaging with the body and environment, the brain constructs neural circuits that act as models of the body and environment. During overt sensorimotor engagement, these models are driven by efference copies in parallel with the body and environment, in order to provide expectations of the sensory feedback, and to enhance and process sensory information. These models can also be run off-line in order to produce imagery, estimate outcomes of different actions, and evaluate and develop motor plans. The framework is initially developed within the context of motor control, where it has been shown that inner models running in parallel with the body can reduce the effects of feedback delay problems. The same mechanisms can account for motor imagery as the off-line driving of the emulator via efference copies. The framework is extended to account for visual imagery as the off-line driving of an emulator of the motor-visual loop. I also show how such systems can provide for amodal spatial imagery. Perception, including visual perception, results from such models being used to form expectations of, and to interpret, sensory input. I close by briefly outlining other cognitive functions that might also be synthesized within this framework, including reasoning, theory of mind phenomena, and language.

The Role of Online Visual Feedback for the Control of Target-Directed and Allocentric Hand Movements

2011 ◽  
Vol 105 (2) ◽  
pp. 846-859 ◽  
Author(s):  
Lore Thaler ◽  
Melvyn A. Goodale
Keyword(s):  
Visual Feedback ◽  
Visual Information ◽  
Sensory Feedback ◽  
Sensory Information ◽  
Movement Control ◽  
Sensorimotor Control ◽  
Hand Movements ◽  
Cast Doubt ◽  
Target Locations

Studies that have investigated how sensory feedback about the moving hand is used to control hand movements have relied on paradigms such as pointing or reaching that require subjects to acquire target locations. In the context of these target-directed tasks, it has been found repeatedly that the human sensory-motor system relies heavily on visual feedback to control the ongoing movement. This finding has been formalized within the framework of statistical optimality according to which different sources of sensory feedback are combined such as to minimize variance in sensory information during movement control. Importantly, however, many hand movements that people perform every day are not target-directed, but based on allocentric (object-centered) visual information. Examples of allocentric movements are gesture imitation, drawing, or copying. Here we tested if visual feedback about the moving hand is used in the same way to control target-directed and allocentric hand movements. The results show that visual feedback is used significantly more to reduce movement scatter in the target-directed as compared with the allocentric movement task. Furthermore, we found that differences in the use of visual feedback between target-directed and allocentric hand movements cannot be explained based on differences in uncertainty about the movement goal. We conclude that the role played by visual feedback for movement control is fundamentally different for target-directed and allocentric movements. The results suggest that current computational and neural models of sensorimotor control that are based entirely on data derived from target-directed paradigms have to be modified to accommodate performance in the allocentric tasks used in our experiments. As a consequence, the results cast doubt on the idea that models of sensorimotor control developed exclusively from data obtained in target-directed paradigms are also valid in the context of allocentric tasks, such as drawing, copying, or imitative gesturing, that characterize much of human behavior.

scholarly journals Intra- and intersegmental influences among central pattern generating networks in the walking system of the stick insect

2017 ◽  
Vol 118 (4) ◽  
pp. 2296-2310 ◽  
Author(s):  
Charalampos Mantziaris ◽  
Till Bockemühl ◽  
Philip Holmes ◽  
Anke Borgmann ◽  
Silvia Daun ◽  
...  
Keyword(s):  
Neural Networks ◽  
Sensory Feedback ◽  
Muscarinic Acetylcholine Receptor ◽  
Central Pattern Generators ◽  
Sensory Information ◽  
Direct Interaction ◽  
Stick Insect ◽  
Weakly Coupled ◽  
The Neural Networks ◽  
Pattern Generators

To efficiently move around, animals need to coordinate their limbs. Proper, context-dependent coupling among the neural networks underlying leg movement is necessary for generating intersegmental coordination. In the slow-walking stick insect, local sensory information is very important for shaping coordination. However, central coupling mechanisms among segmental central pattern generators (CPGs) may also contribute to this. Here, we analyzed the interactions between contralateral networks that drive the depressor trochanteris muscle of the legs in both isolated and interconnected deafferented thoracic ganglia of the stick insect on application of pilocarpine, a muscarinic acetylcholine receptor agonist. Our results show that depressor CPG activity is only weakly coupled between all segments. Intrasegmental phase relationships differ between the three isolated ganglia, and they are modified and stabilized when ganglia are interconnected. However, the coordination patterns that emerge do not resemble those observed during walking. Our findings are in line with recent studies and highlight the influence of sensory input on coordination in slowly walking insects. Finally, as a direct interaction between depressor CPG networks and contralateral motoneurons could not be observed, we hypothesize that coupling is based on interactions at the level of CPG interneurons. NEW & NOTEWORTHY Maintaining functional interleg coordination is vitally important as animals locomote through changing environments. The relative importance of central mechanisms vs. sensory feedback in this process is not well understood. We analyzed coordination among the neural networks generating leg movements in stick insect preparations lacking phasic sensory feedback. Under these conditions, the networks governing different legs were only weakly coupled. In stick insect, central connections alone are thus insufficient to produce the leg coordination observed behaviorally.

scholarly journals Centre of pressure versus centre of mass stabilization strategies: the tightrope balancing case

2020 ◽  
Vol 7 (9) ◽  
pp. 200111
Author(s):  
Pietro Morasso
Keyword(s):  
Degrees Of Freedom ◽  
Sensory Feedback ◽  
Sagittal Plane ◽  
Control Variable ◽  
Variable Number ◽  
Body Parts ◽  
Centre Of Mass ◽  
Centre Of Pressure ◽  
Feedback Controllers ◽  
Neuromotor Control

This study proposes a generalization of the ankle and hip postural strategies to be applied to the large class of skills that share the same basic challenge of defeating the destabilizing effect of gravity on the basis of the same neuromotor control organization, adapted and specialized to a variable number of degrees of freedom, different body parts, different muscles and different sensory feedback channels. In all the cases, we can identify two crucial elements (the CoP, centre of pressure and the CoM, centre of mass) and the central point of the paper is that most balancing skills can be framed in the CoP–CoM interplay and can be modelled as a combination/alternation of two basic stabilization strategies: the standard well-investigated COPS (or CoP stabilization strategy, the default option), where the CoM is the controlled variable and the CoP is the control variable, and the less investigated COMS (or CoM stabilization strategy), where CoP and CoM must exchange their role because the range of motion of the CoP is strongly constrained by environmental conditions. The paper focuses on the tightrope balancing skill where sway control in the sagittal plane is modelled in terms of the COPS while the more challenging sway in the coronal plane is modelled in terms of the COMS, with the support of a suitable balance pole. Both stabilization strategies are implemented as state-space intermittent, delayed feedback controllers, independent of each other. Extensive simulations support the degree of plausibility, generality and robustness of the proposed approach.

scholarly journals Additive Manufacturing of Nerve Decellularized Extracellular Matrix-Contained Polyurethane Conduits for Peripheral Nerve Regeneration

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1612 ◽  
Author(s):  
Chen ◽  
Chen ◽  
Ng ◽  
Lou ◽  
Chen ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Nerve Regeneration ◽  
Nerve Repair ◽  
Sensory Information ◽  
Cellular Adhesion ◽  
Electrical Signal ◽  
Potential Candidate ◽  
Body Parts ◽  
Digital Light Processing ◽  
Nerve Conduits

The nervous system is the part of our body that plays critical roles in the coordination of actions and sensory information as well as communication between different body parts through electrical signal transmissions. Current studies have shown that patients are likely to experience a functional loss if they have to go through a nerve repair for >15 mm lesion. The ideal treatment methodology is autologous nerve transplant, but numerous problems lie in this treatment method, such as lack of harvesting sites. Therefore, researchers are attempting to fabricate alternatives for nerve regeneration, and nerve conduit is one of the potential alternatives for nerve regeneration. In this study, we fabricated polyurethane/polydopamine/extracellular matrix (PU/PDA/ECM) nerve conduits using digital light processing (DLP) technology and assessed for its physical properties, biodegradability, cytocompatibility, neural related growth factor, and proteins secretion and expression and its potential in allowing cellular adhesion and proliferation. It was reported that PU/PDA/ECM nerve conduits were more hydrophilic and allowed enhanced cellular adhesion, proliferation, expression, and secretion of neural-related proteins (collagen I and laminin) and also enhanced expression of neurogenic proteins, such as nestin and microtubule-associated protein 2 (MAP2). In addition, PU/PDA/ECM nerve conduits were reported to be non-cytotoxic, had sustained biodegradability, and had similar physical characteristics as PU conduits. Therefore, we believed that PU/PDA/ECM nerve conduits could be a potential candidate for future nerve-related research or clinical applications.

scholarly journals Advantages of comparative studies in songbirds to understand the neural basis of sensorimotor integration

2017 ◽  
Vol 118 (2) ◽  
pp. 800-816 ◽  
Author(s):  
Karagh Murphy ◽  
Logan S. James ◽  
Jon T. Sakata ◽  
Jonathan F. Prather
Keyword(s):  
Nervous System ◽  
Sensory Feedback ◽  
Sensorimotor Integration ◽  
New Technologies ◽  
Sensory Information ◽  
Neural Basis ◽  
Communication Behaviors ◽  
Song Repertoire ◽  
Evolutionary Variation ◽  
And Control

Sensorimotor integration is the process through which the nervous system creates a link between motor commands and associated sensory feedback. This process allows for the acquisition and refinement of many behaviors, including learned communication behaviors such as speech and birdsong. Consequently, it is important to understand fundamental mechanisms of sensorimotor integration, and comparative analyses of this process can provide vital insight. Songbirds offer a powerful comparative model system to study how the nervous system links motor and sensory information for learning and control. This is because the acquisition, maintenance, and control of birdsong critically depend on sensory feedback. Furthermore, there is an incredible diversity of song organizations across songbird species, ranging from songs with simple, stereotyped sequences to songs with complex sequencing of vocal gestures, as well as a wide diversity of song repertoire sizes. Despite this diversity, the neural circuitry for song learning, control, and maintenance remains highly similar across species. Here, we highlight the utility of songbirds for the analysis of sensorimotor integration and the insights about mechanisms of sensorimotor integration gained by comparing different songbird species. Key conclusions from this comparative analysis are that variation in song sequence complexity seems to covary with the strength of feedback signals in sensorimotor circuits and that sensorimotor circuits contain distinct representations of elements in the vocal repertoire, possibly enabling evolutionary variation in repertoire sizes. We conclude our review by highlighting important areas of research that could benefit from increased comparative focus, with particular emphasis on the integration of new technologies.

scholarly journals Gambaran Gangguan Muskoloskeletal pada Perawat

2020 ◽  
Vol 20 (2) ◽  
pp. 399
Author(s):  
Zifriyanthi Minanda Putri ◽  
Ilfa Khairina ◽  
Randy Refnandes
Keyword(s):  
Musculoskeletal Disorders ◽  
Random Sampling ◽  
Sampling Method ◽  
Soft Tissues ◽  
Health Workers ◽  
Sample Selection ◽  
Nursing Profession ◽  
Body Parts ◽  
Industrial Workers ◽  
Lower Back

Most of the health workers are nursing staff, nursing profession demands high physical activity ranks second after industrial workers. Musculoskeletal disorders often occur in health workers, nurses have a higher risk of experiencing the disorder. Musculoskeletal disorders are disorders that occur in the muscles, bones, tendons, blood vessels, nervous system, and other soft tissues. The purpose of this study was to determine the picture of musculoskeletal disorders in nurses in General Hospital. Dr. M. Djamil Padang. Research Methods: The method used in this research is descriptive. The number of samples in this study were 132 people. The sample selection in this study was the proportional random sampling method. The results showed that more than half (81.1%) nurses experienced musculoskeletal disorders. Musculoskeletal disorders complained of body parts: shoulders 49.2%, neck and lower back 41.7%, and upper back 32.6%. It is expected that nurses can identify the incidence of musculoskeletal disorders due to work and immediately report to management for further prevention.

scholarly journals Cumulative Trauma Disorders

AAOHN Journal ◽  
1992 ◽  
Vol 40 (3) ◽  
pp. 113-116 ◽  
Author(s):  
Linda J. Frederick
Keyword(s):  
Soft Tissues ◽  
Cumulative Trauma ◽  
Occupational Risk Factors ◽  
Biomechanical Stress ◽  
Mechanical Responses ◽  
Health Nurse ◽  
Occupational Health Nurse ◽  
Trauma Disorders ◽  
Forceful Exertion ◽  
Ergonomic Interventions

Data from individual studies and worksites indicate that CTDs are a major problem in some industries. Evidence exists for an association between symptoms of CTDs and occupational risk factors such as forceful exertion, repetitiveness, and extreme postures. Although the pathogenesis of these disorders is not known, they are believed to involve physiological and mechanical responses of soft tissues to repeated or sustained biomechanical stress. The efficacy of ergonomic interventions or programs must be evaluated using the same methods as used to identify problems initially. User (worker) feedback about any job or tool redesigns is essential. Implementing ergonomic interventions likely will be an ongoing, iterative process. The ability of the occupational health nurse to carry out basic nursing functions of health promotion and prevention of injury and illness will be enhanced through the application of the ergonomic principles.

scholarly journals Dynamics and stability of running on rough terrains

2019 ◽  
Vol 6 (3) ◽  
pp. 181729 ◽  
Author(s):  
Nihav Dhawale ◽  
Shreyas Mandre ◽  
Madhusudhan Venkadesan
Keyword(s):  
Sensory Feedback ◽  
Dimensionless Parameter ◽  
Sagittal Plane ◽  
Sensory Information ◽  
Open Loop ◽  
Rough Terrain ◽  
Two Dimensional ◽  
Flat Surfaces ◽  
And Control ◽  
Flat Ground

Stability of running on rough terrain depends on the propagation of perturbations due to the ground. We consider stability within the sagittal plane and model the dynamics of running as a two-dimensional body with alternating aerial and stance phases. Stance is modelled as a passive, impulsive collision followed by an active, impulsive push-off that compensates for collisional losses. Such a runner has infinitely many strategies to maintain periodic gaits on flat ground. However, these strategies differ in how perturbations due to terrain unevenness are propagated. Instabilities manifest as tumbling (orientational instability) or failing to maintain a steady speed (translational instability). We find that open-loop strategies that avoid sensory feedback are sufficient to maintain stability on step-like terrains with piecewise flat surfaces that randomly vary in height. However, these open-loop runners lose orientational stability on rough terrains whose slope also varies randomly. The orientational instability is significantly mitigated by minimizing the tangential collision, which typically requires sensory information and anticipatory strategies such as leg retraction. By analysing the propagation of perturbations, we derive a single dimensionless parameter that governs stability. This parameter provides guidelines for the design and control of both biological and robotic runners.

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