Including nonideal behavior in simulations of functional electrical stimulation applications

Area of Science:

• Biomedical Engineering
• Rehabilitation Engineering
• Neuroscience

Background:

• Functional electrical stimulation (FES) simulations often use idealized muscle responses.
• This leads to optimistic performance predictions, not reflecting real-world challenges.
• Accurate simulation is crucial for effective FES system development.

Purpose of the Study:

• To develop a Simulink block for incorporating non-ideal muscle behavior into FES simulations.
• To enhance the accuracy of predicting FES system performance in individuals with spinal cord injuries (SCI).
• To provide a tool for pre-clinical assessment of FES systems.

Main Methods:

• Developed a custom Simulink block based on data from complete spinal cord injury (SCI) subjects.
• The block modifies nominal muscle responses to include spasms, tremors, and fatigue.
• User-defined parameters control the severity of undesirable muscle behaviors.

Main Results:

• The developed block successfully integrates non-ideal muscle responses into FES simulations.
• Simulations incorporating this block provide a more realistic assessment of FES system performance.
• Demonstrated the block's utility in predicting real-world FES outcomes.

Conclusions:

• The new Simulink block enhances FES simulation accuracy by accounting for non-ideal muscle behavior.
• This tool can improve the design and evaluation of FES systems for SCI rehabilitation.
• Facilitates more reliable pre-clinical assessment, reducing risks in human testing.