Wireless vs. Wired EEG Application 6137-Algorithms in Network Theory 2013

Based on Wireless Recording Systems: From Noninvasive EEG-NIRS to Invasive EEG devices, by M. Savan et al in IEEE Transactions on Biomedical Circuits and Systems, vol. 7, No. 2, April 2013, pp Available on Moodle 2

Terminology EEG – electroencephalography NIRS – near-infrared spectroscopy Hb0 2 – oxyhemoglobin HbR – de-oxyhemoglobin MICS – Medical Implant Communication System BER – Bit Error Rate 3

Noninvasive vs. invasive systems 4

Functional diagram – noninvasive systems 5

Functional diagram – invasive systems 6

NIRS recordings – visual task 1/2 Fig. 8 Measured NIRS recordings (a) NIRS baseline signal (b) Sensor placement and average HbO 2 concentrations for the visual task 7

NIRS recordings – visual task 2/2 Fig. 8 Measured NIRS recordings (c) Averaged relative changes of concentration of HbO 2 and HBR 8

NIRS recordings – motoric task Fig. 8 Measured NIRS recordings (e) Placement of sensors (f) Averaged relative changes of concentration of HbO 2 and HBR 9

Measured noise in EEG 10

EEG recorded from different locations 11

Localizing the epileptogenic zone 12 Fig. 10 Early seizure onset detection allows localizing the epileptogenic zone

Conclusions 1/3 Wireless portable 8 EEG channels 32 NIRS channels Observes hemodynamic activations Records EEG for epilepsy presurgical evaluation 13

Conclusions 2/3 Implantable module offers – Great tunability – Programmable gain – Input referred noise of 0.5 μV RMS – Sampling frequency up to 2kbps for 32 channels 14

Conclusions 3/3 C# based GUI offers – Easy remote control – Tuneability over the implantable system – MICS band bidirectional communication RF link with BER < (raw channel quality of ) Scalable architecture 15