Design of a Robotic Infant Simulator to Understand the Role of the Trunk in Infant Postural Stability and Center of Pressure.

Infants at risk for developmental delays such as Cerebral Palsy, can often be distinguished through observation of their motion and postural stability. In an effort to provide more accessible and quantitative metrics for the early detection of such impairments, this study focuses on the development of a 6-degree of freedom (DOF) robotic infant simulator. The robotic simulator provides insight into the relationship between infant motion and center of pressure (COP), a common measure that is capable of distinguishing impaired infants through quantification of postural stability. We focus on the impact of a 2 DOF motion in the trunk on COP through two experiments where we 1) Compare the impacts on COP of the limbs and the trunk, and 2) Compare the robot's COP to a real infant's. Our results indicate that motion in the trunk plays a strong part in replicating an infant's COP. Additionally, we can observe that changes in COP exhibit clear and repeatable patterns with respect to motion in each DOF. Future directions suggest a look at how different motions in the trunk affect infant COP.