Blood pressure wave propagation-a multisensor setup for cerebral autoregulation studies.

Area of Science:

• Physiology
• Biomedical Engineering
• Neuroscience

Background:

• Cerebral autoregulation is vital for maintaining brain perfusion and oxygenation.
• Non-invasive blood pressure (BP) monitoring is crucial for assessing cerebral autoregulation.
• Pulse transit time (PTT) is a potential non-invasive method to estimate BP, but sensor placement effects require investigation.

Purpose of the Study:

• To investigate if pressure wave propagation velocity differs between the heart-to-brain and heart-to-periphery directions.
• To examine how physiological tasks and health conditions influence these directional PTT variations.
• To introduce a multi-sensor setup for simultaneous measurement of directional PTT.

Main Methods:

• A three-sensor setup was developed, with sensors placed on the neck, chest, and finger.
• Simultaneous BP wave propagation measurements were taken towards the brain and periphery.
• The impact of physiological tasks (maximal blow, Valsalva, breath hold, deep breathing) on relative PTT changes and BP correlations was analyzed.

Main Results:

• Relative PTT changes were higher towards the brain than periphery during maximal blow, Valsalva, and breath hold tasks.
• Conversely, relative PTT change towards the brain was lower during deep breathing.
• Preliminary data indicate that physiological tasks and measurement direction influence relative PTT changes.

Conclusions:

• Directional PTT measurements and specific physiological tasks can affect relative PTT changes.
• The developed three-sensor system offers a practical, neuroimaging-compatible method for cerebral autoregulation studies.
• This setup facilitates comparative analysis of BP wave propagation velocity towards the brain versus the periphery.