A New Multichannel Broadband Nirs System For Quantitative Monitoring Of Brain Hemodynamics And Metabolism During Seizures

We present a newly developed multichannel broadband NIRS (or bNIRS) system that has the capacity to measure changes in light attenuation of 308 NIR wavelengths (610nm to 918nm) simultaneously over 16 different brain locations. To achieve this the instrument uses a lens based spectrometer with a front-illuminated CCD that has a sensor size of 26.8x26mm. This large CCD detector allows the simultaneous binning of 16 detector fibres. The software uses the UCLn algorithm to quantify the changes in oxy-, deoxy- haemoglobin concentration (HbO(2), HHb) and oxidised cytochrome-c-oxidase (oxCCO) simultaneously over 16 different brain locations with 1second sampling rate. We demonstrate the use of the instrument in quantifying brain tissue oxygenation and metabolic activity simultaneously with electrical changes as measured with EEG in children with seizures.