ABSTRACT
Objective: To make an initial assessment of the correlation between immersive virtual reality-based (ILBT) line bisection testing and paper-and-pencil-based line bisection (PLBT) testing in healthy subjects. Design: Diagnostic study. Setting: Research laboratory. Participants: Twenty healthy adults (51.5 [11.0] years old, 55% women; N=20). Interventions: Participants underwent an ILBT and a conventional PLBT in near space (NS) and more distant space (MDS). Correlations between the ILBT and PLBT, deviation rates in the NS and MDS, horizontal gaze distribution, and presence of virtual reality sickness (VRS) were evaluated. Main Outcome Measures: Correlation between the deviation rates of the PLBT and ILBT. Results: There was no significant correlation between the ILBT and PLBT for evaluating the deviation rate of the line bisection test (LBT). There was no significant difference in the deviation rate of the LBTs between the NS and MDS, but there was a significant difference in the horizontal line-of-sight distribution. VRS was not observed as an adverse event. Conclusions: In healthy adult subjects, our results suggested that there was no significant correlation between the deviation rates of the ILBT and PLBT. We also found that the ILBT is a useful and safe method for evaluating the horizontal line-of-sight distribution and percentage deviation of line segments from the center in the NS and MDS without inducing VRS.
ABSTRACT
We present Virtual Reality Self Co-embodiment, a new method for post-stroke upper limb rehabilitation. It is inspired by mirror therapy, where the patient's healthy arm is involved in recovering the affected arm's motion. By tracking the user's head, wrists, and fingers' positions, our new approach allows the handicapped arm to control a digital avatar in order to pursue a reaching task. We apply the concept of virtual co-embodiment to use the information from the unaffected arm and complete the affected limb's impaired motion, which is our added unique feature. This requires users to mechanically involve the incapacitated area as much as possible, prioritizing actual movement rather than the sole imagination of it. As a result, subjects will see a seemingly normally functional virtual arm primarily controlled by their handicapped extremity, but with the constant support of their healthy limb's motion. Our experiment compares the task execution performance and embodiment perceived when interacting with both mirror therapy and our proposed technique. We found that our approach's provided sense of ownership is mildly impacted by users' motion planning response times, which mirror therapy does not exhibit. We also observed that mirror therapy's sense of ownership is moderately affected by the subject's proficiency while executing the assigned task, which our new method did not display. The results indicate that our proposed method provides similar embodiment and rehabilitation capabilities to those perceived from existing mirror therapy. This experiment was performed in healthy individuals to have an unbiased comparison of how mirror therapy's and VRSelfCo's task performance and degree of virtual embodiment compare, but future work explores the possibility of applying this new approach to actual post-stroke patients.
