Date of Award

Spring 2010

Document Type


Degree Name

Master of Science (MS)


Biomedical Engineering

First Advisor

Harris, Gerald F.

Second Advisor

Riedel, Susan A.

Third Advisor

Valles, Karla Bustamante


Studies of children with cerebral palsy (CP) have shown that maintaining control of posture in quiet standing is often difficult. Physical therapy and assistive devices, both with or without surgery, may be employed in an effort to improve postural stability. Assessing the effectiveness of such interventions is important for healthcare providers and their patients. A previously created bi-planar model of posture control has been further developed as a method of assessment. This MATLAB and Simulink model has successfully replicated experimental results for typical adults and children, as well as children with CP across three different test conditions: eyes open, eyes closed, and eyes open with feedback.

Currently, a main disadvantage of the model is the time-consuming process of fitting the model parameters to the experimental data, because a human operator is required to change the model parameters manually. This parameter-fitting process takes many hours, and after completion there is no guarantee that the fit is optimal. To address these challenges, the current project aims to remove this disadvantage by modifying the simulation model for children with CP so that the parameters are automatically adjusted according to an algorithm designed to minimize a cost function. Because the project is automated, no human intervention is required, and the cost function minimization guarantees an optimal fit. It is anticipated that developing this automated software tool will aid in pre-surgery analysis and patient consultation, leading the way to provide those affected by balance disorders with a more comprehensive overview of potential solutions to their problem.