The first activity patients could “play” (and the first activity we designed) in CogniviveVR was called Rally Zone. It was presented to patients as an arcade game in the resort’s lounge. In Rally Zone, players needed to hit a virtual ball with a racket and use it to break several neon-colored blocks in the distance, similar to a first-person Breakout. The goal of the game was to break all of the blocks in each level as fast as possible. The challenge of the game came from the fact that the player held the racket in their “affected” hand (i.e. the hand/arm the patient was working to improve through therapy). Thus, in order to hit the ball, the patient would have to move their injured arm with precision, which is a major goal of stroke rehab.
Where Rally Zone became truly compelling and an effective therapy tool was in the physics of the ball.
First, we adjusted the trajectory of the ball so it would always return to a place our Therapeutic Adaptive Difficulty System determined would be therapeutically beneficial. For example, if the system estimated that the player could only reach 4 inches past their shoulder, we might adjust the trajectory of the Rally Zone ball so it would pass the player roughly 4 inches away from their shoulder. By encouraging the player to reach toward the edge of their limited range of motion, we encouraged them to expand that range.
Second, we adjusted the trajectory of the ball off the racket so that it would always hit at least one block before returning to them. We then told the player that the ball could break more blocks before returning to them if they either hit the ball harder or hit it multiple times without missing. This “controlled trajectory” mechanic removed any risk of demotivating moments: if the player hit the ball they made progress towards their goal. It also encouraged two behaviors that were therapeutically beneficial for more advanced players: moving with speed, and moving with consistency.
Finally, we changed the physics of the ball so players only needed to touch it with their racket to put it into play, instead of striking it. This helped our most disabled players feel powerful without risking injury by wildly swinging their arm.
In concert, all of these mechanics made for an exciting, compelling experience that had patients performing arm extension exercises for 5-10 minutes at a time without complaint. In fact, most of the patients we interviewed claimed that it was the most fun they’ve had doing rehab exercises. At least one patient even found the experience “empowering”, claiming that it was the most she had felt able to use her affected arm in years.