The Treatment of Akinesia using Virtual Images

by Jerrold D. Prothero

Overview

So far as we know, this study is the first to examine the application of head-up display technology to producing kinesia paradoxa. The primary focus, therefore, is on a qualitative exploration of the basic questions listed in Chapter 3. For this purpose, we tried as wide a range of trial conditions as we could, to get a general feel for the relevant factors, and let the results guide the unfolding of the study.

The range of stimuli fed into the VV Sport display are described in Subsection 5.1.1. Briefly, the stimuli consisted of computer animations, taped images, or a live fed from a video camera. The general idea was to provide images which moved down the screen at about the rate that the subject was walking, so as to give the impression that the image was at a fixed location on the floor.

We also ran a confirmation phase with a second subject in which we checked our conclusions. As part of that phase, we took quantitative gait measurements.

We anticipate that future studies will focus more specifically on factors addressed in a general way in this work.

The study can be seen as containing the following steps (these are described in more detail in Chapter 5).

• Exploratory Phase
  • Can virtual images provide ambulatory cues?
    • Use of actual objects in front of subject
    • Camera panning objects from above while subject walks over unobstructed floor, with camera feed to VV Sport display.
    • Pre-recorded objects played back to VV Sport display
    • Computer-generated objects played to VV Sport display
  • Field-of-view requirements
    • Determination of optimal vertical field-of-view
  • Initiating and sustaining cues
    • Use of playing card initial cue
    • Use of imaginary initial cue
    • Use of laser pointer for initial cue
  • Use of laser pointer for sustaining ambulation
  • Sustained ambulation without cues
• Confirmation phase
  • Qualitative
    • VV system with computer-generated cues
    • Laser pointer with sustained gait
  • Quantitative
    • No cues
    • Laser pointer
    • VV Sport display with no stimulus
    • VV Sport display with stimulus