Headband-type near-infrared spectroscopy device for measuring oxyhemoglobin in frontal cortex

Near-infrared spectroscopy (NIRS) is an important technique that percutaneously and noninvasively monitors the changes in hemoglobin concentration of cerebral blood flow. We have developed headband-type NIRS devices using a light-emitting diode (LED) power source and a photodiode detector (PD) to reduce the burden in diagnosis preparation and the price of the NIRS module. The ten-channel nonreal-time headband-type NIRS device with PD and one-package three-wavelength LED as well as the two-channel real-time wireless NIRS headband that is controlled using a tablet PC were manufactured in house. The two developed headband NIRS devices were evaluated using an existing LABNIRS system using a verbal fluency task, and they exhibited the same tendency with NIRS signals of the different levels at the rest and task stages. The measurement of the real-time NIRS signals revealed that the voice and breath caused the source of low-frequency fluctuations superimposed on the NIRS signals. © 2017 The Institute of Electrical Engineers of Japan.