Oxygen-dependent functional brain haemodynamic response.

The influence of hypoxia - a condition where tissues are under oxygen deficiency - on the human brain under functional load has not been fully understood yet. This study aims to analyse the effects of hypoxia on the brain's haemodynamic response under visual stimulation, using the in-house developed functional near-infrared spectroscopy system and to quantify the hemodynamic response. Our results (median, 25 and 75 percentile) demonstrate the amplitude of the oxygenated haemoglobin functional response during hypoxia 0.30 µM (0.27, 0.41) was lower compared with the normoxia 0.63 µM (0.54, 0.93) and hyperoxia 0.73 µM (0.43, 1.09). No statistical significance is observed for the deoxygenated haemoglobin changes. The hypoxia has a statistically significant effect on the amplitude of the haemodynamic response (p < 0.001).