Epilepsy, the common neurological disorder, afflicts about 1% of world’s population. Epileptic seizures are caused by sudden excessive electrical discharges in a group of cortical neurons. Currently, numerous anti-epileptic drugs are available for seizure control. However, there are still nearly one-third of the patients remain either drug-resistant or develop limiting adverse effects. The alternative and effective clinical treatment for drug-resistant epilepsy is the resection surgery of removing the epileptogenic zone or the implantation of neuromodulators.
Recently, implantable devices with closed-loop electrical stimulation for epileptic seizure control have been presented as a potential and effective clinical treatment. As shown in clinical data, up to 3mA electrical stimulation on cortical surface at seizure onset sites is required to control human epileptic seizures. However the electrical stimulations in the reported systems could not satisfy the above requirement
In this presentation, a closed-loop neuromodulation System-on-Chip (SOC) with adjustable 0.5?3mA biphasic current stimulation is described. The SoC is powered wirelessly and bidirectional telemetry is realized through the same pair of coils in ISM band (13.56MHz). The clinical applications of the implantable closed-loop epileptic seizure control system will be presented.
Before the treatment of resection surgery or neuromodulator implant, the patients must take careful pre-surgical brain mapping process to identify the seizure onset zone or determine the most suitable neuro-stimulation parameters. All commercial brain mapping equipment systems are lack of real-time closed-loop electrical stimulation. The proposed brain mapping system for pre-surgical evaluation is the integration of brain wave acquisition, seizure onset detection, closed-loop electrical stimulation, and on-demand electrodes selection for electrical stimulation. The prototype of the proposed equipment will be described.
Finally, future development on closed-loop neuromodulation systems will be discussed. |
