Hemi is composed of physical controllers and a digital platform with games. By interacting with the controllers, kids can improve their hand-motor skills while playing digital games designed to allow the repetition of hand movements with a therapeutic effect. The main component is a motion sensor ball that uses Inertial Measurement Unit (IMU) sensor technology. By attaching different handles and knobs to it and placing the ball into different cases, the child can build different types of controllers. Each controller includes two different handles or knobs to encourage children to exercise a variety of hand grips and hand movements.

Cerebral palsy (CP) is the most common physical disability in childhood, it is caused by damage to the brain and has no cure. Hemiplegia, where half of the body has difficulty with voluntary movement, is the most common presentation of CP. Studies show that continuous arm-hand rehabilitation is crucial for these kids to improve their quality of life. Specialists recommend additional home therapy to extend the therapeutic benefits. However, there is a lack of continuity of progress in the home environment due to low motivation or unengaging therapy tools.

This design is meant to be easily upgraded, making it more sustainable and accessible for the home environment. By adding new attachments and cases, but still using the same motion sensor ball component, it gives the possibility to create new controllers to exercise other arm-hand movements without adding too many extra costs. Hemi provides parents with a variety of fun therapeutic games for different hand movements, so they do not have to stress planning all the exercises beforehand.