Oxygenation and Blood Volume Periodic Waveforms in the Brain

TL;DR

This study investigates how slow, periodic breathing influences cerebral oxygenation and blood volume, revealing synchronized oscillations in brain oxygen levels and blood volume with breathing cycles.

Contribution

It demonstrates a clear link between respiration and cerebral oxygenation using non-invasive measurements in yoga practitioners performing slow breathing exercises.

Findings

Cerebral oxygenation oscillates with the same period as breathing.

Blood volume index shows similar periodic changes.

Results support a connection between respiration and brain oxygenation.

Abstract

Results of an experiment are presented whose aim is to explore the relationship between respiration and cerebral oxygenation. Measurements of end tidal CO2 (EtCO2) were taken simultaneously with cerebral oxygen saturation (rSO2) using the INVOS Cerebral Oximeter of Somanetics. Due to the device limitations we could explore only subjects who could perform with a breathing rate of around 2/min or less. Six subjects were used who were experienced in yoga breathing techniques. They performed an identical periodic breathing exercise including periodicity of about 2/min. The results of all six subjects clearly show a periodic change of cerebral oxygenation with the same period as the breathing exercises. Similar periodic changes in blood volume index were observed as well.