A simple set up for the measurement of patient response time in fMRI

Because blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) pulse sequences have rapidly changing high field gradients, almost all currently available equipment which measure and record the response of a patient to visual or audio stimuli in fMRI employ fiber-optics based systems. In this work we introduce a simple and low cost patient response set up which does not require fiber-optics based sensors and interface. The basis of the method is to transmit an on/off light signal through the RF shielded window of the scanning room. The performance of the proposed measurement set up is tested using fMRI sequences in a 3 Tesla MRI unit.