This poster will present the initial stages of development of a Spirometer input device, servo controlled airflow valve and XNA-based video game. This system will be developed as a possible treatment tool for engaging older children with Cystic Fibrosis to perform breathing exercises. Interaction with the game will involve breathing into the Spirometer device. The device will be programmed to measure airflow and the data will be used to control outcome of the game. Active valve control will be explored as a potential game mechanic.