Hypertension is a well-known major risk factor for cardiovascular diseases, stroke, kidney failure, aortic aneurysm and other complications resulting in serious health conditions.
Neuronal activity is known to be associated with then changes in the blood oxygenation and deoxygenation due to functional brain activities. These changes are referred to cerebral hemodynamics.
The difference in the near-infrared absorption spectra of oxyhemoglobin (HbO2) and deoxyhemoglobin (HbR) enables the concentrations of the two molecules to be separately identified. NIRS employs wavelengths of 600?900 nm, which experience very low levels of absorption in tissues, allowing deeper enetration into a brain tissue.