Investigation of cerebral hemodynamic changes during a repeated sit-stand maneuver using functional near-infrared spectroscopy

摘要

The goal for this study is to examine cerebral autoregulation in response to a repeated sit-stand maneuver usingboth diffuse functional Near Infrared spectroscopy (fNIRS) and Transcranial Doppler sonography (TCD). WhilefNIRS can provide transient changes in hemodynamic response to such a physical action, TCD is a noninvasivetranscranial method to detect the flow velocities in the basal or middle cerebral arteries (MCA). The initialphase of this study was to measure fNIRS signals from the forehead of subjects during the repeated sit-standprotocol and to understand the corresponding meaning of the detected signals. Also, we acquired preliminarydata from simultaneous measurements of fNIRS and TCD during the sit-stand protocol so as to explore thetechnical difficulty of such an approach. Specifically, ten healthy adult subjects were enrolled to perform theplanned protocol, and the fNIRS array probes with 4 sources and 10 detectors were placed on the subject'sforehead to detect hemodynamic signal changes from the prefrontal cortex. The fNIRS results show that theoscillations of hemoglobin concentration were spatially global and temporally dynamic across the entire regionof subject's forehead. The oscillation patterns in both hemoglobin concentrations and blood flow velocityseemed to follow one another; changes in oxy-hemoglobin concentration were much larger than those in deoxy-hemoglobin concentration. These preliminary findings provide us with evidence that fNIRS is an appropriatemeans readily for studying cerebral hemodynamics and autoregulation during sit-stand maneuvers.