TH-208. Development and Evaluation of a Transcutaneous Stimulator for the Treatment of Refractory Epilepsy

ABSTRACT

Introduction: The design and first results of a transcutaneous electrical stimulator of the vagus nerve for the treatment of Refractory Epilepsy are discussed. Method(s) The device developed is based on the STM32L073CZ microcontroller and can generate fully configurable monopolar or bipolar stimuli, so that the electrical therapy can be adjusted to each patient following the therapeutic strategy designed by their doctor. The start time and duration of each therapeutic session are stored in an internal memory of the device, as well as the instants in which the contact of the electrodes is poor, or the therapeutic session is aborted. In this way, the doctor in charge can review what happened once the information is downloaded to a personal computer. Using 3D printing techniques, a plastic support for the electrodes was developed that allows the automatic adjustment of these to the left ear of the subject undergoing treatment;this ensures placement of the electrodes on the correct ear and proper contact of the electrodes with the skin. The operation of the device is easy, each session starts by pressing a button and ends automatically when the programmed time expires, the intervention of the subject undergoing treatment is minimal and thus stress is avoided. Result(s) 20 prototypes were built and passed technical tests in accordance with IEC 60601-1 and IEC 60601-2-10 standards. The results were satisfactory and thus it is guaranteed that the proposed solution is safe for patients and the techniques used are in the state of the art within this medical technology. The Cuban regulatory body approved a trial with 18 humans to test the effectiveness of the device developed;each patient will be under treatment for nine months, but not all began simultaneously due to restrictions put in place by the COVID-19 pandemic. Electrical stimulation was set as follows bipolar square pulses of 200 microseconds duration at 25 Hz;three 60-minute sessions per day. A patient is considered as treatment's responder monthly crisis frequency decrease more than 50% that he suffered before starting treatment. To date, six patients have completed the trial, five with significant improvement. The other twelve patients are in treatment and after the third month the Monthly Seizure Frequency has decreased in all of them. Conclusion(s) The proposed solution has been effective in the first six patients ending the trial. Without concluding the study, the proposed solution seems an outstanding therapeutic solution. Copyright © 2022