Our Virtual Reality Fall Risk Assessment Tool

In order to interact with our tool, users must wear the HTC Vive head-mounted headset. A virtual scenario resembling an empty room is then presented. This room consists of an exercise area (demarked by a light blue square) with two small white rectangles indicating the starting position of the test. Users can walk freely in this room. To eliminate any distractions, light colours and a simplistic level design were chosen. Two red shoes mirroring the movements of the user’s feet are also presented. This helps the user to concentrate on the stepping task and allows them to have a sense of presence in the virtual environment. HTC Vive controllers are attached to the user’s lower limbs using a set of elastic bands. This is to allow for the tracking of the foot movements and the animation of the virtual shoes in an unobtrusive manner. The field of view is slighted shifted in a way that the user can see themselves from behind. Previous studies have indicated that this view-mode could offer a more comfortable and immersive experiences.

Test mechanics resemble the original CSRT task. Stepping stimuli are presented in the virtual system in the form of a green ellipsoid (or pellet) (See Figure 1). Users are expected to react to this by taking a quick reactive step towards the pellet with the leg that is closest to the stimulus (see Figure 2). As soon as the virtual shoe collides with the pellet, the latter disappears from the screen. Users must then return to the initial position as quickly as possible. Once this is completed, the process starts over in a randomized order and location (front-left, front-right, back-left, back-right, left or right). This is to prevent users from memorizing stepping patterns and instead forcing them to react to the stepping stimuli.