Fig. 1From: Nonlinear estimation of BOLD signals with the aid of cerebral blood volume imagingSchematic illustration of the hemodynamic balloon model. This model consists of three linked subsystems: (1) neural activity u(t) to changes in the cerebral blood flow f, the second-order time derivative equation is written as a set of two first-order time derivative equations by introducing a new state variable \(s=\dot{f}\); (2) changes in flow f to changes in the cerebral blood volume v; (3) changes in flow f, volume v and oxygen extraction fraction to changes in the veins in the vein dHb content q Back to article page