Wireless assistance system during episodes of freezing of gait by means superficial electrical stimulation

Parkinson’s disease in an advanced stage presents the symptom of freezing of gait, approximately 80% of patients may have a freeze after 17 years of illness, provoking falls and injuries in the 60% of them, the medication is obsolete before this symptom. In search of new methodologies and instruments to help improve the lifestyle of these patients, a non-invasive wireless system is proposed to detect freezing and restart walking by means of superficial electrical stimulation during an episode. A sensor based on a triaxial accelerometer placed on the posterior secondary nerve was used to acquire and store the data of the right lower extremity during the presence of a freezing episode. The data was processed on a smartphone with Android operative system using the tool of discrete wavelet transform developed in Java. The transcutaneous electrical stimulation is applied near the posterior tibial nerve of the lower extremities to continue the walk, which presents better results compared to the vibratory stimulation presented in an earlier version from the authors. The results show feasible diagnostic tests for the validation of the system, such as precision, sensitivity and specificity.