Ground Controller

Children at the Shirley Ryan AbilityLab enjoy using the Xbox Adaptive Controller for both rehabilitation and leisure. However, many Xbox games require the use of two joysticks, which are typically controlled with two hands. Several patients at the AbilityLab do not have motion in both hands, and thus need a joystick that can be controlled without the use of hands to have full autonomy when playing these games. Otherwise, verbal communication is needed so that Mr. Rafferty can control the second joystick as a co-pilot.

My team researched existing products such as the Stinkyboard and 3D Rudder, which provide opportunities to control a video game with the feet, but they require two feet and are not easy to use. 

We met with users and found that the Adaptive Controller was not an intuitive device for replacing a standard controller, patients in wheelchairs have different heights from the ground, and some users had limited mobility on one side of their body. This told us that the controller should be able to be used with either side of the body and not depend on the user’s feet touching the floor.

From our observations and by working with our client, we developed more requirements: cleanable, one-size-fits-all, compatible with Xbox One, comfortable, stationary, durable, and allow full range of motion within the game.

The client was interested in a joystick that could be used with the feet, so we developed alternatives with this concept in mind. Created alternatives matrix to evaluate options.

We created mockups of these alternatives and performed user testing with them. We found that the final design must have much stronger connection points that can withstand the force of the leg pushing on the joystick and can bear the weight of the leg resting on it. The angled platform was unnecessary because the joystick was most comfortable to use when it is flat. The sensitivity of the joystick must be low so that the strong and fast motions of the foot do not cause the player in the Xbox game to move uncontrollably fast. 

The users liked that the joystick alternatives returned to the neutral position on their own, which eliminated the mouse ball. With no need for the angled platform, the final design will combine the foot pad and flat joystick concepts into a flat foot pad attached to a joystick post.

We designed multiple foot plate alternatives and asked for user feedback of the different shape options (circle, oval, rectangle). The user did not like the circular option because it felt unstable and less comfortable than the other options because it had less contact area with the foot. Because it used less material, we decided to move forward with the oval design. We used CAD and laser cutter to create a final PVC foot plate. We also included a screw attachment so that alternative foot plates could be developed in the future. 

During the user testing, we also tested the joystick base that we purchased to ensure it was compatible with the Xbox One and provided the spring back to neutral position that the users wanted. We also reprogrammed the sensitivity of the joystick with the users to optimize it for the strength of foot movements in relation to hand movements.

We built a final prototype for the client to use with his patients. The base containing the electronic components could be opened to allow repairs or replacement of parts. The joystick was supported by wood so that the weight of the user’s feet didn’t push the joystick deeper into the base.