Evaluation of mediVR-KAGURA Guided Therapy: A Prospective Interventional Study

The patients sit on an upright chair, wear a head-mounted display (HMD) and grab two handheld controllers in a motion-tracked three-dimensional space called "room scale" of the mediVR-KAGURA (mediVR, Inc. Toyonaka City, Osaka, Japan). mediVR-KAGURA can provide users with >90 frames per second (fps) graphic operation with an approximately 110° viewing angle and accurate three-dimensional tracking technology.

First, we evaluate conventional and maximum reaching distances at 0°, 45°, and 90° level surface for the left hand (0L, 45L, 90L) and at 90°, 135°, and 180° level surface for the right hand (90R, 135R, or 180R) for calibration in a sitting position. During rehabilitation, patients are instructed to touch a fixed objects or catch a falling objects at the pre-specified height and distance levels in each degree. Horizontal distances were classified into three categories, namely long, middle, and short which were calculated using the following formulas: 0.9 * maximum reaching distance, 0.9 * (conventional + maximum reaching distances)/2, and conventional reaching distance respectively. A falling object disappeared at a 20 cm height for safety if the patients missed to catch it. The purpose of reaching hands was to stimulate and break down body trunk balance, and to train participants to balance for stable walking. By thinking about the timing and distance and recognizing the next targets repeatedly, cognitive function was simultaneously stimulated for dual-task training.

The 7 parameters of the rehabilitation programs can be set like as follows: (1) distance (short, middle or long), (2) direction (0L, 45L, 90L, 90R, 135R, or 180R), (3) height of object, (4) size of object (center or outline), (5) size of sensing sphere of the controller, (6) falling speed of the square box (from 0 to 300 cm/s), and (7) intervals for each task. Participants first underwent practical programs to familiarize themselves with mediVR-KAGURA guided rehabilitation, followed by rehabilitation programs. Provision of the rehabilitation programs will be personalized.