Implantable Multi-modality Probe for Subdural Simultaneous Measurement of Electrophysiology, Hemodynamics, and Temperature Distribution
Multi-channel multi-modality measurement capabilities of near-infrared spectroscopy (NIRS), electrocorticography (ECoG), and temperature distribution were integrated into a single, flexible device compact enough for subdural implantation. Photoelectric bare chips for NIRS channels, miniature temperature-coefficient thermistors for measuring localized temperature variation, and 3-mm-diameter platinum plates for ECoG recording were assembled on a flexible printed circuit to create six channels for each modality. A conformal coating of Parylene-C was applied to make the probe surface biocompatible. The simultaneous measurement capability of the developed probe was examined, with IRB approval, in subjects during surgery and post-operative monitoring with no complications throughout the two-week implantation.
Epileptic Seizure Prediction Based on Multivariate Statistical Process Control of Heart Rate Variability Features
We proposed a new epileptic seizure prediction method utilizing heart rate variability (HRV) analysis. It monitors time-frequency-domain HRV features for predicting seizures by using multivariate statistical process control (MSPC). The application results to clinical data produced accurate predictions (91%) for epileptic seizures and there were few false-positives (0.7 times/hour). The possibility of realizing a HRV-based epileptic seizure prediction system was shown.