Showing papers by "Robert V. Kenyon published in 2005"

Integration of Augmented Reality and Assistive Devices for Post-Stroke Hand Opening Rehabilitation

Abstract: Impairment of hand function is prevalent among stroke survivors, motivating the search for effective rehabilitation therapy. Recent studies have suggested that for upper extremity functional recovery, repetitive training with virtual reality is helpful. Repetitive training can be facilitated with assistance from mechanical devices. Thus, we have developed a training environment that integrates augmented reality (AR) with assistive devices for post-stroke hand rehabilitation. The AR element of our environment utilizes head mounted display and virtual objects for reach-and-grasp task training. The assistive device consists of either a body-powered orthosis (BPO) or a pneumatic-powered device (PPD), both of which are incorporated into gloves. This environment can be easily set up and calibrated, is customizable for individual users, and requires active user participation. Additionally, it can be used with both real and virtual objects, as desired. We are currently conducting pilot case studies to assess ease of use and efficacy. At present, one stroke survivor from each of the three training conditions, AR-with-BPO, AR-with-PPD and AR-only (acting as the control), has completed the 6-week training paradigm. Preliminary findings suggest user acceptance of the technology and some potential for beneficial effects

An augmented reality training environment for post-stroke finger extension rehabilitation

Abstract: Finger extension is an important hand function and is crucial for object exploration and manipulation. Unfortunately, the impairment of this motor function is common among stroke survivors. A training environment incorporating augmented reality (AR) in conjunction with assistive devices has been developed for the rehabilitation of finger extension. The environment consists of three components: the stroke survivor user element consisting of AR equipment/software and body-powered orthosis; the therapist element comprised of monitoring/control interface with visual, audio and force feedback; and the networking module which interconnects these two. In this paper we present the structure of this environment along with the results from a pilot case study with a stroke survivor.

Employing a virtual environment in postural research and rehabilitation to reveal the impact of visual information

Abstract: We have united an immersive virtual environment with support surface motion to record biomechanical and physiological responses to combined visual, vestibular, and proprioceptive inputs. We have examined age-related differences during peripheral visual field motion and with a focal image projected on to the moving virtual scene. Our data suggest that the postural response is modulated by all existing sensory signals in a non-additive fashion. An individual’s perception of the sensory structure appears to be a significant component of the postural response in these protocols. We will discuss the implications of these results to clinical interventions for balance disorders.

Comparing adaptation of constrained and unconstrained movements in three dimensions

Abstract: This paper describes targeted reaching experiments conducted using a new augmented reality system. Combining a large-workspace immersive virtual environment with physical force feedback, the system distorted subjects' movements using a viscous curl force field. Following previous experiments using a different robot, half the subjects were constrained to horizontal, planar movements. The remaining subjects performed unconstrained movements throughout the 3D workspace. Examining after-effects as an indication of learning, we found that constrained subjects learned the force field. However, it was difficult to detect whether the unconstrained subjects learned forces of identical magnitude. Our results found that force fields strengths eliciting constrained 2D adaptation have difficulty exhibiting after-effects for unconstrained 3D movements. The increased motor variability for 3D reaching movements requires consideration for future experimental design.