FIGURE 1.
A hybrid NIRS/DCS instrument for continuous and simultaneous measurements of Δ[HbO2], Δ[Hb] and relative change in CBF (rCBF) before, during and after head-up-tilting (HUT). A, Illustration of a titling bed, and baseline, HUT, and recovery positions. B, A hybrid NIRS/DCS probe with multiple source-detector (S-D) separations. C, A hybrid instrument integrating a commercial NIRS device (Imagent, ISS) and a laboratory-made DCS device. CBF, cerebral blood flow; DCS, diffuse correlation spectroscopy; Hb, deoxy-hemoglobin concentration; HbO2, oxy-hemoglobin concentration; NIRS, near-infrared spectroscopy