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https://www.readbyqxmd.com/read/28814047/a-simple-tool-to-measure-spasticity-in-spinal-cord-injury-subjects
#1
Arash Arami, Nevio L Tagliamonte, Federica Tamburella, Hsieng-Yung Huang, Marco Molinari, Etienne Burdet
This work presents a wearable device and the algorithms for quantitative modelling of joint spasticity and its application in a pilot group of subjects with different levels of spinal cord injury. The device comprises light-weight instrumented handles to measure the interaction force between the subject and the physical therapist performing the tests, EMG sensors and inertial measurement units to measure muscle activity and joint kinematics. Experimental tests included the passive movement of different body segments, where the spasticity was expected, at different velocities...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28814035/decoding-of-individual-finger-movements-from-surface-emg-signals-using-vector-autoregressive-hierarchical-hidden-markov-models-varhhmm
#2
Nebojsa Malesevic, Dimitrije Markovic, Gunter Kanitz, Marco Controzzi, Christian Cipriani, Christian Antfolk
In this paper we present a novel method for predicting individual fingers movements from surface electromyography (EMG). The method is intended for real-time dexterous control of a multifunctional prosthetic hand device. The EMG data was recorded using 16 single-ended channels positioned on the forearm of healthy participants. Synchronously with the EMG recording, the subjects performed consecutive finger movements based on the visual cues. Our algorithm could be described in following steps: extracting mean average value (MAV) of the EMG to be used as the feature for classification, piece-wise linear modeling of EMG feature dynamics, implementation of hierarchical hidden Markov models (HHMM) to capture transitions between linear models, and implementation of Bayesian inference as the classifier...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28814027/challenges-in-using-compliant-ligaments-for-position-estimation-within-robotic-joints
#3
Felix Russell, Lei Gao, Peter Ellison, Ravi Vaidyanathan
The mechanical advantages of bio-inspired condylar robotic knee joints for use in prosthetics or rehabilitation has been argued extensively in literature. A common limitation of these designs is the difficulty of estimating joint angle and therefore accurately controlling the joint. Furthermore, the potential role of ligament-like structures in robotic knees is not very well established. In this work, we investigate the role of compliant stretch sensing ligaments and their integration into a condylar robotic knee...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28814005/distance-based-kinematics-of-the-five-oblique-axis-thumb-model-with-intersecting-axes-at-the-metacarpophalangeal-joint
#4
Nicolas Rojas, Aaron M Dollar
This paper proposes a novel and simple method to compute all possible solutions of the inverse kinematics problem of the five-oblique-axis thumb model with intersecting axes at the metacarpophalangeal joint. This thumb model is one of the suggested results by a magnetic-resonance-imaging-based study that, in contrast to those based on cadaver fingers or on the tracking of the surface of the fingers, takes into account muscle and ligament behaviors and avoids inaccuracies resulting from the movement of the skin with respect to the bones...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813938/online-sparse-gaussian-process-based-human-motion-intent-learning-for-an-electrically-actuated-lower-extremity-exoskeleton
#5
Yi Long, Zhi-Jiang Du, Chao-Feng Chen, Wei Dong, Wei-Dong Wang
The most important step for lower extremity exoskeleton is to infer human motion intent (HMI), which contributes to achieve human exoskeleton collaboration. Since the user is in the control loop, the relationship between human robot interaction (HRI) information and HMI is nonlinear and complicated, which is difficult to be modeled by using mathematical approaches. The nonlinear approximation can be learned by using machine learning approaches. Gaussian Process (GP) regression is suitable for high-dimensional and small-sample nonlinear regression problems...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813910/reference-path-generation-for-upper-arm-exoskeletons-considering-scapulohumeral-rhythms
#6
Rana Soltani-Zarrin, Amin Zeiaee, Reza Langari, Nina Robson
This paper proposes a reference path generation method for upper-limb rehabilitation exoskeletons considering the scapulohumeral rhythms of the shoulder. The developed method is based on Central Nervous System's (CNS) governing rules for coordination of arm motions, and to the best of our knowledge is the first computational model to consider the motion of the inner shoulder in path generation. Existing reference generation methods which utilize computational models such as minimum jerk, minimum torque, etc, are based on the assumption that the shoulder joint does not move, and the origin of the reference frame is defined at the center of the glenohumeral (GH) joint...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813846/closed-loop-emg-informed-model-based-analysis-of-human-musculoskeletal-mechanics-on-rough-terrains
#7
C Varotto, Z Sawacha, L Gizzi, D Farina, M Sartori
This work aims at estimating the musculoskeletal forces acting in the human lower extremity during locomotion on rough terrains. We employ computational models of the human neuro-musculoskeletal system that are informed by multi-modal movement data including foot-ground reaction forces, 3D marker trajectories and lower extremity electromyograms (EMG). Data were recorded from one healthy subject locomoting on rough grounds realized using foam rubber blocks of different heights. Blocks arrangement was randomized across all locomotion trials to prevent adaptation to specific ground morphology...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813816/computational-rehabilitation-of-neglect-using-state-space-models-to-understand-the-recovery-mechanisms
#8
Giulia Sedda, Marcella Ottonello, Elena Fiabane, Caterina Pistarini, Anna Sedda, Vittorio Sanguineti
Unilateral spatial neglect is a neuropsychological syndrome often observed in right hemisphere stroke patients. The symptoms differ from subject to subject. A few rehabilitation approaches, e.g. prism adaptation, have demonstrated some effect in reducing the symptoms, but the underlying mechanisms are still largely unclear. Recently, neural models have been proposed to qualitatively describe cortical lesions, the resulting neglect symptoms and the effects of treatment. However, these predictions are qualitative and cannot be used to compare different hypotheses or to interpret symptoms at individual subjects level...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813815/how-do-strength-and-coordination-recovery-interact-after-stroke-a-computational-model-for-informing-robotic-training
#9
Sumner L Norman, Joan Lobo-Prat, David J Reinkensmeyer
Robotic devices can train strength, coordination, or a combination of both. If a robotic device focuses on coordination, what happens to strength recovery, and vice versa? Understanding this interaction could help optimize robotic training. We developed a computational neurorehabilitation model to gain insight into the interaction between strength and coordination recovery after stroke. In the model, the motor system recovers by optimizing the activity of residual corticospinal cells (focally connected, excitatory and inhibitory) and reticulospinal cells (diffusely connected and excitatory) to achieve a motor task...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813800/the-effects-of-control-signal-noise-on-simultaneous-submovements
#10
Kathleen R Wilson, Kevin B Englehart, Jon W Sensinger
Understanding the stereotypical characteristics of human movement can better inform rehabilitation practices by providing a template of healthy and expected human motor control. Multiplicative noise is inherent in goal-directed movement, such as reaching to grasp an object. Multiplicative noise plays an important role in computational motor control models to help support phenomena such as stereotypical kinematic profiles in time-constrained and unconstrained tasks. Most tasks are not carried out along an isolated degree-of-freedom (DOF), and modelling the contribution of noise can be difficult...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813643/multi-connection-pattern-analysis-decoding-the-representational-content-of-neural-communication
#11
Yuanning Li, R Mark Richardson, Avniel Singh Ghuman
The lack of multivariate methods for decoding the representational content of interregional neural communication has left it difficult to know what information is represented in distributed brain circuit interactions. Here we present Multi-Connection Pattern Analysis (MCPA), which works by learning mappings between the activity patterns of the populations as a factor of the information being processed. These maps are used to predict the activity from one neural population based on the activity from the other population...
August 13, 2017: NeuroImage
https://www.readbyqxmd.com/read/28813570/experimental-and-numerical-characterization-of-the-mechanical-masseter-muscle-response-during-mastication
#12
Johannes Weickenmeier, Mahmood Jabareen, Benjamin J D Le Révérend, Marco Ramaioli, Edoardo Mazza
Predictive simulations of the mastication system would significantly improve our understanding of temporomandibular joint disorders and the planning of cranio-maxillofacial surgery procedures. Respective computational models must be validated by experimental data from in-vivo characterization of the mastication system's mechanical response. The present work introduces a combined experimental and numerical procedure for the validation of a computer model of the masseter muscle during biting. The proposed experimental setup enables simultaneous bite force measurements and ultrasound-based visualization of masseter deformation for the direct comparison with the numerically predicted masseter response...
August 16, 2017: Journal of Biomechanical Engineering
https://www.readbyqxmd.com/read/28813564/multi-inducer-grouping-for-curve-completion-perceptual-and-computational-exploration
#13
Nir-Cohen Gal, Arad Boaz, Ben-Shahar Ohad
The human visual system excels in object recognition and scene interpretation even in scenes in which some (or even all) observed objects are partially occluded or fragmented. This highly efficient capacity is facilitated by constructive processes of contour completion between inducers to yield the perception of whole objects across gaps. A fundamental problem of the process is when and how the visual system groups different inducers in the visual scene between which completion occurs. Previous studies on this grouping problem, inspired mostly by relatability theory (Kellman & Shipley, 1991), focused on one good continuation condition that dictates whether a given pair of inducers would group together or not...
August 1, 2017: Journal of Vision
https://www.readbyqxmd.com/read/28813535/modeling-hypothermia-induced-effects-for-the-heterogeneous-ventricular-tissue-from-cellular-level-to-the-impact-on-the-ecg
#14
Roland Kienast, Michael Handler, Markus Stöger, Daniel Baumgarten, Friedrich Hanser, Christian Baumgartner
Hypothermia has a profound impact on the electrophysiological mechanisms of the heart. Experimental investigations provide a better understanding of electrophysiological alterations associated with cooling. However, there is a lack of computer models suitable for simulating the effects of hypothermia in cardio-electrophysiology. In this work, we propose a model that describes the cooling-induced electrophysiological alterations in ventricular tissue in a temperature range from 27°C to 37°C. To model the electrophysiological conditions in a 3D left ventricular tissue block it was essential to consider the following anatomical and physiological parameters in the model: the different cell types (endocardial, M, epicardial), the heterogeneous conductivities in longitudinal, transversal and transmural direction depending on the prevailing temperature, the distinct fiber orientations and the transmural repolarization sequences...
2017: PloS One
https://www.readbyqxmd.com/read/28813442/a-parallel-metaheuristic-for-large-mixed-integer-dynamic-optimization-problems-with-applications-in-computational-biology
#15
David R Penas, David Henriques, Patricia González, Ramón Doallo, Julio Saez-Rodriguez, Julio R Banga
BACKGROUND: We consider a general class of global optimization problems dealing with nonlinear dynamic models. Although this class is relevant to many areas of science and engineering, here we are interested in applying this framework to the reverse engineering problem in computational systems biology, which yields very large mixed-integer dynamic optimization (MIDO) problems. In particular, we consider the framework of logic-based ordinary differential equations (ODEs). METHODS: We present saCeSS2, a parallel method for the solution of this class of problems...
2017: PloS One
https://www.readbyqxmd.com/read/28813231/time-frequency-cross-mutual-information-analysis-of-the-brain-functional-networks-underlying-multiclass-motor-imagery
#16
Anmin Gong, Jianping Liu, Si Chen, Yunfa Fu
To study the physiologic mechanism of the brain during different motor imagery (MI) tasks, the authors employed a method of brain-network modeling based on time-frequency cross mutual information obtained from 4-class (left hand, right hand, feet, and tongue) MI tasks recorded as brain-computer interface (BCI) electroencephalography data. The authors explored the brain network revealed by these MI tasks using statistical analysis and the analysis of topologic characteristics, and observed significant differences in the reaction level, reaction time, and activated target during 4-class MI tasks...
August 16, 2017: Journal of Motor Behavior
https://www.readbyqxmd.com/read/28813156/the-spatial-resolution-limit-for-individual-domain-wall-in-magnetic-nanowires
#17
Sumit Dutta, Saima Afroz Siddiqui, Jean Anne Currivan-Incorvia, Caroline A Ross, Marc A Baldo
Magnetic nanowires are the foundation of several promising nonvolatile computing devices, most notably magnetic racetrack memory and domain wall logic. Here, we determine the analog information capacity in these technologies, analyzing a magnetic nanowire containing a single domain wall. Although wires can be deliberately patterned with notches to define discrete positions for domain walls, the line edge roughness of the wire can also trap domain walls at dimensions below the resolution of the fabrication process, determining the fundamental resolution limit for the placement of a domain wall...
August 16, 2017: Nano Letters
https://www.readbyqxmd.com/read/28813098/modeling-and-mapping-basal-area-of-pinus-taeda-l-plantation-using-airborne-lidar-data
#18
Carlos A Silva, Carine Klauberg, Andrew T Hudak, Lee A Vierling, Scott J Fennema, Ana Paula D Corte
Basal area (BA) is a good predictor of timber stand volume and forest growth. This study developed predictive models using field and airborne LiDAR (Light Detection and Ranging) data for estimation of basal area in Pinus taeda plantation in south Brazil. In the field, BA was collected from conventional forest inventory plots. Multiple linear regression models for predicting BA from LiDAR-derived metrics were developed and evaluated for predictive power and parsimony. The best model to predict BA from a family of six models was selected based on corrected Akaike Information Criterion (AICc) and assessed by the adjusted coefficient of determination (adj...
August 14, 2017: Anais da Academia Brasileira de Ciências
https://www.readbyqxmd.com/read/28813000/an-ameliorated-prediction-of-drug-target-interactions-based-on-multi-scale-discrete-wavelet-transform-and-network-features
#19
Cong Shen, Yijie Ding, Jijun Tang, Xinying Xu, Fei Guo
The prediction of drug-target interactions (DTIs) via computational technology plays a crucial role in reducing the experimental cost. A variety of state-of-the-art methods have been proposed to improve the accuracy of DTI predictions. In this paper, we propose a kind of drug-target interactions predictor adopting multi-scale discrete wavelet transform and network features (named as DAWN) in order to solve the DTIs prediction problem. We encode the drug molecule by a substructure fingerprint with a dictionary of substructure patterns...
August 16, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28812984/modelling-the-effects-of-quinidine-disopyramide-and-e-4031-on-short-qt-syndrome-variant-3-in-the-human-ventricles
#20
Cunjin Luo, Kuanquan Wang, Henggui Zhang
Short QT syndrome (SQTS) is an inherited cardiac channelopathy, but at present little information is available on its pharmacological treatment. SQT3 variant (linked to the inward rectifier potassium current IK1) of SQTS, results from a gain-of-function mutation (Kir2.1 D172N) in the KCNJ2-encoded channels, which is associated with ventricular fibrillation (VF). Using biophysically-detailed human ventricular computer models, this study investigated the potential effects of quinidine, disopyramide, and E-4031 on SQT3...
August 16, 2017: Physiological Measurement
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