Monitoring tibialis anterior responses of post-stroke patients under electroacupuncture therapy with inertial sensors

Electroacupuncture (EA) is often used in China for treatment of muscle spasticity in post-stroke patients, however the duration of EA stimulation is decided subjectively currently since there is no objective means of outcome monitoring for EA. To explore a potential prompt monitoring technique for EA, inertial sensor system is used in this study on tibialis anterior (TA) muscle under EA therapy among 4 volunteered patients. The module of inertial sensor system is deployed onto the tiptoe to monitor the response of TA during EA stimulation. Totally 18 valid datasets are acquired including both those from 3-axes accelerators and 3-axes gyroscopes in the experiments. The root-mean-square (RMS), average rectified value (ARV) and mean power frequency (MPF) for the accelerator signals and the dynamic range of the tiptoe relative angle (DRA) for the gyroscope signals are then computed. It's found that after EA treatment, the dynamic range of TA response decreased in terms of RMS, ARV and DRA, while MPF of the accelerator signals increased. The inertial sensors, as wearable they are, might add a promising objective monitoring means of EA therapy, suggested by the results in the preliminary study.