Uncertainty Estimation in Functional Electrical Stimulation Procedures for Knee Extension Movement

Abstract

This work proposes an observer able to estimate uncertainties inherent to the application of functional electrical stimulation (FES) on knee-joint extension movements, for instance in patients with spinal cord injury during rehabilitation sessions. The proposed observer structure is based on a disturbance observer, which is capable of estimating the deviation of system’s response from an adopted nominal value. One of the proposed methodology main advantages is avoiding determining a specific model for each individual, simplifying the FES procedure and enhancing its chances of application on a large number of subjects. The attained results with actual data suggest that the proposed observer is capable of precisely estimating both the states and the uncertainties affecting the physiologic systems during FES procedures.