scholarly journals Multidigit force control during unconstrained grasping in response to object perturbations

2017 ◽  
Vol 117 (5) ◽  
pp. 2025-2036 ◽  
Author(s):  
Abdeldjallil Naceri ◽  
Alessandro Moscatelli ◽  
Robert Haschke ◽  
Helge Ritter ◽  
Marco Santello ◽  
...  
Keyword(s):  
Nervous System ◽  
Control Algorithm ◽  
External Disturbance ◽  
Human Hand ◽  
Force Distribution ◽  
Robotic Hand ◽  
Robotic Grasping ◽  
Motor Synergies ◽  
Complex Anatomy ◽  
The Central Nervous System

Because of the complex anatomy of the human hand, in the absence of external constraints, a large number of postures and force combinations can be used to attain a stable grasp. Motor synergies provide a viable strategy to solve this problem of motor redundancy. In this study, we exploited the technical advantages of an innovative sensorized object to study unconstrained hand grasping within the theoretical framework of motor synergies. Participants were required to grasp, lift, and hold the sensorized object. During the holding phase, we repetitively applied external disturbance forces and torques and recorded the spatiotemporal distribution of grip forces produced by each digit. We found that the time to reach the maximum grip force during each perturbation was roughly equal across fingers, consistent with a synchronous, synergistic stiffening across digits. We further evaluated this hypothesis by comparing the force distribution of human grasping vs. robotic grasping, where the control strategy was set by the experimenter. We controlled the global hand stiffness of the robotic hand and found that this control algorithm produced a force pattern qualitatively similar to human grasping performance. Our results suggest that the nervous system uses a default whole hand synergistic control to maintain a stable grasp regardless of the number of digits involved in the task, their position on the objects, and the type and frequency of external perturbations. NEW & NOTEWORTHY We studied hand grasping using a sensorized object allowing unconstrained finger placement. During object perturbation, the time to reach the peak force was roughly equal across fingers, consistently with a synergistic stiffening across fingers. Force distribution of a robotic grasping hand, where the control algorithm is based on global hand stiffness, was qualitatively similar to human grasping. This suggests that the central nervous system uses a default whole hand synergistic control to maintain a stable grasp.

scholarly journals Augmented Reality Interface for Complex Anatomy Learning in the Central Nervous System: A Systematic Review

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Rahmita Wirza ◽  
Shah Nazir ◽  
Habib Ullah Khan ◽  
Iván García-Magariño ◽  
Rohul Amin
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Augmented Reality ◽  
Human Body ◽  
Medical Information ◽  
Quality Criteria ◽  
Gesture Interaction ◽  
Complex Anatomy ◽  
The Central Nervous System ◽  
Comprehensive Study

The medical system is facing the transformations with augmentation in the use of medical information systems, electronic records, smart, wearable devices, and handheld. The central nervous system function is to control the activities of the mind and the human body. Modern speedy development in medical and computational growth in the field of the central nervous system enables practitioners and researchers to extract and visualize insight from these systems. The function of augmented reality is to incorporate virtual and real objects, interactively running in a real-time and real environment. The role of augmented reality in the central nervous system becomes a thought-provoking task. Gesture interaction approach-based augmented reality in the central nervous system has enormous impending for reducing the care cost, quality refining of care, and waste and error reducing. To make this process smooth, it would be effective to present a comprehensive study report of the available state-of-the-art-work for enabling doctors and practitioners to easily use it in the decision making process. This comprehensive study will finally summarise the outputs of the published materials associate to gesture interaction-based augmented reality approach in the central nervous system. This research uses the protocol of systematic literature which systematically collects, analyses, and derives facts from the collected papers. The data collected range from the published materials for 10 years. 78 papers were selected and included papers based on the predefined inclusion, exclusion, and quality criteria. The study supports to identify the studies related to augmented reality in the nervous system, application of augmented reality in the nervous system, technique of augmented reality in the nervous system, and the gesture interaction approaches in the nervous system. The derivations from the studies show that there is certain amount of rise-up in yearly wise articles, and numerous studies exist, related to augmented reality and gestures interaction approaches to different systems of the human body, specifically to the nervous system. This research organises and summarises the existing associated work, which is in the form of published materials, and are related to augmented reality. This research will help the practitioners and researchers to sight most of the existing studies subjected to augmented reality-based gestures interaction approaches for the nervous system and then can eventually be followed as support in future for complex anatomy learning.

scholarly journals Sloppy, But Acceptable, Control of Biological Movement: Algorithm-Based Stabilization of Subspaces in Abundant Spaces

2019 ◽  
Vol 67 (1) ◽  
pp. 49-72 ◽  
Author(s):  
Vladimir M. Akulin ◽  
Frederic Carlier ◽  
Stanislaw Solnik ◽  
Mark L. Latash
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Main Idea ◽  
Human Hand ◽  
Performance Variables ◽  
Neural Processes ◽  
Simple Rules ◽  
The Central Nervous System ◽  
Local Feedback ◽  
Motor Actions

Abstract In this paper, we develop an algorithm-based approach to the problem of stability of salient performance variables during motor actions. This problem is reformulated as stabilizing subspaces within high-dimensional spaces of elemental variables. Our main idea is that the central nervous system does not solve such problems precisely, but uses simple rules that achieve success with sufficiently high probability. Such rules can be applied even if the central nervous system has no knowledge of the mapping between small changes in elemental variables and changes in performance. We start with a rule ”Act on the most nimble” (the AMN-rule), when changes in the local feedback-based loops occur for the most unstable variable first. This rule is implemented in a task-specific coordinate system that facilitates local control. Further, we develop and supplement the AMN-rule to improve the success rate. Predictions of implementation of such algorithms are compared with the results of experiments performed on the human hand with both visual and mechanical perturbations. We conclude that physical, including neural, processes associated with everyday motor actions can be adequately represented with a set of simple algorithms leading to sloppy, but satisfactory, solutions. Finally, we discuss implications of this scheme for motor learning and motor disorders.

Effects of Hyperoxia on Lung Utrastructure

1970 ◽  
Vol 28 ◽  
pp. 26-27
Author(s):  
Gladys Harrison
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Light Microscopy ◽  
Oxygen Effects ◽  
Age Dependent ◽  
The Central Nervous System ◽  
The Subject ◽  
Space Age ◽  
Alveolar Septa ◽  
Extensive Damage

With the advent of the space age and the need to determine the requirements for a space cabin atmosphere, oxygen effects came into increased importance, even though these effects have been the subject of continuous research for many years. In fact, Priestly initiated oxygen research when in 1775 he published his results of isolating oxygen and described the effects of breathing it on himself and two mice, the only creatures to have had the “privilege” of breathing this “pure air”.Early studies had demonstrated the central nervous system effects at pressures above one atmosphere. Light microscopy revealed extensive damage to the lungs at one atmosphere. These changes which included perivascular and peribronchial edema, focal hemorrhage, rupture of the alveolar septa, and widespread edema, resulted in death of the animal in less than one week. The severity of the symptoms differed between species and was age dependent, with young animals being more resistant.

Emigration of neutrophils in the central nervous system

1983 ◽  
Vol 41 ◽  
pp. 788-789
Author(s):  
John L.Beggs ◽  
John D. Waggener ◽  
Wanda Miller ◽  
Jane Watkins
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Osmium Tetroxide ◽  
White Blood Cells ◽  
Arterial Perfusion ◽  
E Coli ◽  
Intracisternal Injection ◽  
The Central Nervous System ◽  
Brain And Spinal Cord ◽  
Interendothelial Junctions

Studies using mesenteric and ear chamber preparations have shown that interendothelial junctions provide the route for neutrophil emigration during inflammation. The term emigration refers to the passage of white blood cells across the endothelium from the vascular lumen. Although the precise pathway of transendo- thelial emigration in the central nervous system (CNS) has not been resolved, the presence of different physiological and morphological (tight junctions) properties of CNS endothelium may dictate alternate emigration pathways.To study neutrophil emigration in the CNS, we induced meningitis in guinea pigs by intracisternal injection of E. coli bacteria.In this model, leptomeningeal inflammation is well developed by 3 hr. After 3 1/2 hr, animals were sacrificed by arterial perfusion with 3% phosphate buffered glutaraldehyde. Tissues from brain and spinal cord were post-fixed in 1% osmium tetroxide, dehydrated in alcohols and propylene oxide, and embedded in Epon. Thin serial sections were cut with diamond knives and examined in a Philips 300 electron microscope.

Mammalian Bone Marrow Acetylcholinesterase

1982 ◽  
Vol 40 ◽  
pp. 44-45
Author(s):  
Ezzatollah Keyhani
Keyword(s):  
Central Nervous System ◽  
Bone Marrow ◽  
Nervous System ◽  
Common Property ◽  
Extracellular Medium ◽  
The Central Nervous System ◽  
The Common ◽  
Mammalian Bone

Acetylcholinesterase (EC 3.1.1.7) (ACHE) has been localized at cholinergic junctions both in the central nervous system and at the periphery and it functions in neurotransmission. ACHE was also found in other tissues without involvement in neurotransmission, but exhibiting the common property of transporting water and ions. This communication describes intracellular ACHE in mammalian bone marrow and its secretion into the extracellular medium.

The Red Neuronal Pigment in the Nervous System of the Mussel, Mytilus Edulis: Localization and Its Effect on Lateral Ciliary Activity with Spectral and Analytical Changes

1981 ◽  
Vol 39 ◽  
pp. 494-495
Author(s):  
Anthony A. Paparo ◽  
Judith A. Murphy
Keyword(s):  
Nervous System ◽  
Mytilus Edulis ◽  
Neuronal Cell ◽  
Ciliary Activity ◽  
Neuronal Cell Bodies ◽  
The Central Nervous System ◽  
Intracellular Organelles ◽  
The Common ◽  
The Individual ◽  
Cryostat Sections

The purpose of this study was to localize the red neuronal pigment in Mytilus edulis and examine its role in the control of lateral ciliary activity in the gill. The visceral ganglia (Vg) in the central nervous system show an over al red pigmentation. Most red pigments examined in squash preps and cryostat sec tions were localized in the neuronal cell bodies and proximal axon regions. Unstained cryostat sections showed highly localized patches of this pigment scattered throughout the cells in the form of dense granular masses about 5-7 um in diameter, with the individual granules ranging from 0.6-1.3 um in diame ter. Tissue stained with Gomori's method for Fe showed bright blue granular masses of about the same size and structure as previously seen in unstained cryostat sections.Thick section microanalysis (Fig.l) confirmed both the localization and presence of Fe in the nerve cell. These nerve cells of the Vg share with other pigmented photosensitive cells the common cytostructural feature of localization of absorbing molecules in intracellular organelles where they are tightly ordered in fine substructures.

Glucuronyl 3-sulfate occurs exclusively on distal unmyelinated terminals of selected sensory neurons in the peripheral nervous system

1995 ◽  
Vol 53 ◽  
pp. 958-959
Author(s):  
S.S. Spicer ◽  
B.A. Schulte
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cerebral Cortex ◽  
Peripheral Nervous System ◽  
Sensory Neurons ◽  
Sensory Nerves ◽  
Tissue Antigens ◽  
The Central Nervous System ◽  
The Brain ◽  
Leu 7

Generation of monoclonal antibodies (MAbs) against tissue antigens has yielded several (VC1.1, HNK- 1, L2, 4F4 and anti-leu 7) which recognize the unique sugar epitope, glucuronyl 3-sulfate (Glc A3- SO4). In the central nervous system, these MAbs have demonstrated Glc A3-SO4 at the surface of neurons in the cerebral cortex, the cerebellum, the retina and other widespread regions of the brain.Here we describe the distribution of Glc A3-SO4 in the peripheral nervous system as determined by immunostaining with a MAb (VC 1.1) developed against antigen in the cat visual cortex. Outside the central nervous system, immunoreactivity was observed only in peripheral terminals of selected sensory nerves conducting transduction signals for touch, hearing, balance and taste. On the glassy membrane of the sinus hair in murine nasal skin, just deep to the ringwurt, VC 1.1 delineated an intensely stained, plaque-like area (Fig. 1). This previously unrecognized structure of the nasal vibrissae presumably serves as a tactile end organ and to our knowledge is not demonstrable by means other than its selective immunopositivity with VC1.1 and its appearance as a densely fibrillar area in H&E stained sections.

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