Abstract Purpose Intact tactile perception is essential to successfully interact with objects. While examinations exist for capturing impairments, recent investigations underscore that these remain insufficient, particularly adults following a neurological injury. To inform the design of improved assessments, this study comprehensively captures factors can influence in young and older who are neurologically intact. Methods We examined impact arm dominance (dominant/non-dominant), nerve...

This study compares the Weber fraction for human perception of stiffness among three conditions: vision, proprioceptive motion feedback, and their combination. To make comparisons between these feedback conditions, a novel haptic device was designed that senses spring behavior through encoder force measurements, implements controller to render linear virtual springs so stimuli displayed haptically could be compared with visual counterparts. The custom-designed, torque-controlled interface...

This research seeks to ascertain the relative value of visual and proprioceptive motion feedback during force-based control a non-self entity like powered prosthesis. Accurately controlling such device is very difficult when operator cannot see or feel movement that results from applied forces. As an analogy prosthesis use, we tested importance targeted movement. Thirteen human subjects performed virtual finger-pointing task in which finger's velocity was always programmed be directly...

Manipulating objects with an upper limb prosthesis requires significantly more visual attention than doing the same task intact limb. Prior work and comments from individuals lacking proprioception indicate that conveying motion through a nonvisual sensory channel would reduce possibly remove need to watch prosthesis. To motivate design of suitable substitution devices, this study investigates difference between seeing virtual prosthetic move feeling one's real move. Fifteen subjects...

Post-stroke flexion synergy limits arm/hand function and is also linked to hyperactive stretch reflexes or spasticity. It implicated in the increased role of indirect motor pathways following damage direct corticospinal projections. We hypothesized that this maladaptive neuroplasticity affects reflexes. Specifically, multi-synaptic interactions may increase nonlinear neural connectivity time lag between reflex muscle response. Continuous position perturbations were applied elbow joint when...

This work lays the foundation for future research on quantitative modeling of human stiffness perception. Our goal was to develop a method by which human's ability perceive suprathreshold haptic force stimuli and can be affected adding noise.Five participants performed same-different task with one-degree-of-freedom force-feedback device. Participants used right index finger actively interact variations (∼5 ∼8 N) (∼290 N/m) that included one four scaled amounts haptically rendered noise...

Upper-limb prostheses users lack proprioception of their artificial arm, and rely heavily on vision to understand its configuration. With the goal reducing amount energy expended visual cues during upper-limb prosthesis use, this study investigates whether haptic feedback can relay configuration a virtual hand in absence sight. Two mappings from waistbelt-mounted tactor vibration patterns are explored: (1) Synergy-based motions derived results principal component analysis run an aggregate...

Haptic feedback for upper-limb prostheses is desirable to enable a user interact naturally with his or her environment, including operating the limb without vision and performing activities of daily living. We present noninvasive method providing one type haptic feedback, vibration, an prosthesis discrimination environment properties. Using telemanipulation system that emulates ideal prosthesis, able-bodied subjects tapped on materials varying stiffness while vibration signals were recorded...

We describe a sensory augmentation system designed to provide the visually disabled with sense of color. Our consists glove short-range optical color sensors mounted on its fingertips, and torso-worn belt which tactors (haptic feedback actuators) are mounted. Each fingertip sensor detects observed object's This information is encoded tactor through vibrations in respective locations varying modulations. Early results suggest that detection primary colors possible near 100% accuracy moderate...

Background. Prior work indicates that 50-75% of individuals post-hemiparetic stroke have upper-extremity weakness and, in turn, inaccurately judge the relative torques their arms generate during a bimanual task. Recent findings also reveal these differently depending on whether they reference paretic versus non-paretic arm. Objective. Our goal was to determine with hemiparetic matched between arms, regardless arm referenced. Methods. Fifteen participants and ten right-hand dominant controls...

Activation-related sensory gating is important for sensorimotor control, filtering signals irrelevant to a task. Literature on brain lateralization suggests that motor activation patterns during control differ depending arm dominance. Whether the effect extends how modulate voluntary remains unaddressed. We compared tactile between arms of older adults. Eight right-arm dominant participants received single-pulse, 100 μs square-wave electrotactile stimulus at their testing arm's fingertip or...

Knob turning is a common task that should influence the design of human-machine interfaces such as prosthetic arms, teleoperated robots, and virtual environments. This study examines following metrics for specified knob rotation: strategy, including arm motions used number grasps made, time to complete motion, maximum applied forces torques. The subjects' was rotate one-degree-of freedom haptic at least 270 degrees two angles attack (hand parallel versus perpendicular plane knob), three...

Background According to between-arms assessments, more than 50% of individuals with stroke have an impaired position sense. Our previous work, which employed a clinical assessment and slightly differing tasks, indicates that who deficit on between-forearms position-localization task do not necessarily single-forearm task. Objective goal here was to, using robotics tools, determine whether when matching forearm positions within arm also mirroring between arms, independent the leads Methods...

Abstract Successful execution of daily activities requires accurate perception the torques one generates about multiple joints. Even so, previous studies are mostly limited to an individual’s when generated a single joint. Consequently, this study investigates how accurately individuals judge at their arm during multi-joint task. The accuracy fifteen right-hand dominant participants (age: 60 ± 10 years) in matching isometric elbow torques, within same arm, was quantified single- and/or...

Post hemiparetic stroke an individual may face difficulty performing bimanual tasks due to asymmetry in their arms' strengths. Here, we determined whether participants with a strength were impaired bi-directionally when matching torques between arms (i.e., paretic arm matches non-paretic arm, arm). Six chronic and four without neurological impairments partook this study. First, identified the maximum voluntary torque that could generate about each elbow joint (τ <sub...

Background: Successful execution of a task as simple drinking from cup and complicated cutting food with fork knife requires accurate perception the torques that one generates in each arm. Prior studies have shown individuals hemiparetic stroke inaccurately judge their self-generated during bimanual tasks; yet, it remains unclear whether these unimanual tasks. Objective: The goal this work was to determine affected how accurately perceive single-arm task. Methods: Fifteen fifteen without...

Accurate perception of one's self-generated torques is integral to sensorimotor control. Here, we examined how features the motor control task, specifically variability, duration, muscle activation pattern, and magnitude torque generation, relate torque. Nineteen participants generated perceived 25% their maximum voluntary (MVT) in elbow flexion while simultaneously abducting at shoulder 10%, 30%, or 50% MVT abduction (MVT[Formula: see text]). Subsequently, matched without feedback...