scholarly journals Mechanisms of neuro-robotic prosthesis operation in leg amputees

2021 ◽  
Vol 7 (17) ◽  
pp. eabd8354
Author(s):  
Giacomo Valle ◽  
Albulena Saliji ◽  
Ezra Fogle ◽  
Andrea Cimolato ◽  
Francesco M. Petrini ◽  
...  
Keyword(s):  
Sensory Feedback ◽  
Walking Speed ◽  
Sensory Information ◽  
Neural Stimulation ◽  
Motor Tasks ◽  
Wearable Robotics ◽  
Cognitive Benefits ◽  
Leg Amputees ◽  
Robotic Leg ◽  
Robotic Prosthesis

Above-knee amputees suffer the lack of sensory information, even while using most advanced prostheses. Restoring intraneural sensory feedback results in functional and cognitive benefits. It is unknown how this artificial feedback, restored through a neuro-robotic leg, influences users’ sensorimotor strategies and its implications for future wearable robotics. To unveil these mechanisms, we measured gait markers of a sensorized neuroprosthesis in two leg amputees during motor tasks of different difficulty. Novel sensorimotor strategies were intuitively promoted, allowing for a higher walking speed in both tasks. We objectively quantified the augmented prosthesis’ confidence and observed the reshaping of the legs’ kinematics toward a more physiological gait. In a possible scenario of a leg amputee driving a conventional car, we showed a finer pressure estimation from the prosthesis. Users exploited different features of the neural stimulation during tasks, suggesting that a simple prosthesis sensorization could be effective for future neuro-robotic prostheses.

scholarly journals Sensory feedback restoration in leg amputees improves walking speed, metabolic cost and phantom pain

2019 ◽  
Vol 25 (9) ◽  
pp. 1356-1363 ◽  
Author(s):  
Francesco Maria Petrini ◽  
Marko Bumbasirevic ◽  
Giacomo Valle ◽  
Vladimir Ilic ◽  
Pavle Mijović ◽  
...  
Keyword(s):  
Sensory Feedback ◽  
Walking Speed ◽  
Metabolic Cost ◽  
Phantom Pain ◽  
Leg Amputees

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 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 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 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.

Modulation of prey-capture behavior in the plethodontid salamander Ensatina eschscholtzii

1997 ◽  
Vol 200 (14) ◽  
pp. 1951-1964 ◽  
Author(s):  
S Deban
Keyword(s):  
High Speed ◽  
Sensory Feedback ◽  
Prey Capture ◽  
Prey Size ◽  
Sensory Information ◽  
Prey Type ◽  
Jaw Movements ◽  
Plethodontid Salamander ◽  
Ensatina Eschscholtzii ◽  
Prey Capture Behavior

The hypothesis that salamander prey-capture behavior is highly stereotyped was tested in the plethodontid salamander Ensatina eschscholtzii using high-speed videography and kinematic analysis of feedings on two types of prey (waxworms and termites). The results show that E. eschscholtzii is capable of modulating the timing and magnitude of tongue and jaw movements in response to prey type. Feedings on waxworms, the larger prey, were characterized by shorter durations and higher velocities of tongue and jaw movements compared with feedings on termites, particularly in the latter portion of the feeding sequence (i.e. after prey contact). To test the hypothesis that sensory feedback through the tongue pad plays a role in modulating feeding movements in response to prey type, the ramus lingualis of the glossopharyngeal nerve (cranial nerve IX), which is known to carry sensory information from the tongue pad in salamanders, was transected bilaterally. This experimental deafferentation of the tongue pad had no effect on the degree or direction of differences in feeding kinematics across prey type. These results refute the glossopharyngeal feedback hypothesis, but are consistent with the hypothesis that E. eschscholtzii responds more vigorously to larger prey by assessing prey size visually.

Advances in robotic prostheses

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rob Bogue
Keyword(s):  
Signal Processing ◽  
Design Methodology ◽  
Sensory Feedback ◽  
Control Strategies ◽  
Short Introduction ◽  
Content Type ◽  
Non Invasive ◽  
Computer Interfaces ◽  
Prosthesis Control ◽  
Robotic Prosthesis

Purpose This paper aims to provide details of recent advances in robotic prostheses with the emphasis on the control and sensing technologies. Design/methodology/approach Following a short introduction, this paper first discusses the main robotic prosthesis control strategies. It then provides details of recent research and developments using non-invasive and invasive brain–computer interfaces (BCIs). These are followed by examples of studies that seek to confer robotic prostheses with sensory feedback. Finally, brief conclusions are drawn. Findings A significant body of research is underway involving electromyographic and BCI technologies, often in combination with advanced data processing and analysis schemes. This has the potential to yield robotic prostheses with advanced capabilities such as greater dexterity and sensory feedback. Originality/value This illustrates how electromyographic, BCI, signal processing and sensor technologies are being used to create robotic prostheses with enhanced functionality.

Vestibular-Neck Interaction and Transformation of Sensory Coordinates

1997 ◽  
Vol 7 (4) ◽  
pp. 347-365
Author(s):  
T. Mergner ◽  
W. Huber ◽  
W. Becker
Keyword(s):  
Postural Control ◽  
Sensory Information ◽  
Physical Space ◽  
The Body ◽  
Support Surface ◽  
Coordinate Transformations ◽  
Motor Tasks ◽  
Postural Stabilization ◽  
Canal Systems ◽  
Self Motion

The article considers findings and concepts on vestibular-proprioceptive interaction for self-motion perception and postural control under the form of simple describing models. It points out that vestibular-neck interaction is only a small fraction of an extended mechanism of coordinate transformations. This links together the different parts of our bodies, so that sensory information arising in one part of the body can be used for perceptual or motor tasks in other parts. Particular emphasis is put on the problems that arise from imperfect signal transduction in the vestibular semicircular canal systems at low stimulus frequencies/velocities. Also, a “down-and-up-channeling” principle is suggested, by which the body support is linked via coordinate transformations to the internal notion of physical space provided by the vestibular system. Furthermore, the following question is addressed: how does the brain use visual input to overcome the vestibular deficiencies, at the risk of visual self-motion illusions? Finally, a conceptual model of postural control is presented in which a proprioceptive feedback that links the body to its support surface is merged with a loop for postural stabilization in space.

Sign in / Sign up

Export Citation Format

Share Document