Multiple optodes configuration for measuring the absolute hemodynamic response using spatially resolved spectroscopy method: An fNIRS study

The paper presents a method for measuring the absolute hemoglobin concentration using a multiple optodes configuration. The functional near-infrared spectroscopy (fNIRS) is used for obtaining the data of the right individual two-finger movement (i.e., thumb and index fingers) in the left motor cortex. The measured light intensities of four healthy male subjects are converted to the absolute hemoglobin concentration levels by using the spatially resolved spectroscopy approach. The t-value of each channel is computed for generating the activation brain map. It is noteworthy that our work is firstly about detection of the active positions in the same brain region using the fNIRS technique with multiple optodes configuration. The experimental results revealed that the proposed method could measure the absolute hemoglobin concentration. The active channels of individual two-finger movement were found in the different territories. However, it also had the active overlapped areas between the index and thumb finger movement.