Forehead skin microcirculation during tilt table testing and lower body negative pressure.

Area of Science:

• Physiology
• Biomedical Engineering
• Cardiovascular Research

Background:

• Orthostatic intolerance involves complex cardiovascular control.
• Understanding microcirculation changes is crucial for spaceflight and terrestrial applications.
• Near Infrared (NIR) sensing offers a noninvasive method for assessing skin microcirculation.

Purpose of the Study:

• To evaluate blood volume and flow motion changes during simulated weightlessness and active standing.
• To analyze pulsatile spectral patterns in skin microcirculation under orthostatic and antiorthostatic stress.
• To assess the utility of a novel NIR sensor technique in hemodynamic studies.

Main Methods:

• Utilized a tilt table experiment simulating head-down tilt (-6 degrees) and active standing using the Tschibis-LBNP device.
• Employed a new noninvasive Near Infrared (NIR) sensor technique for skin microcirculation measurements.
• Measured changes in blood volume, flow motion, and pulsatile spectral patterns.

Main Results:

• Observed significant alterations in skin microcirculation parameters during orthostatic and antiorthostatic challenges.
• Demonstrated the capability of NIR sensing to detect dynamic changes in peripheral blood flow.
• Identified specific spectral patterns associated with cardiovascular responses to simulated weightlessness and standing.

Conclusions:

• The novel NIR sensor technique is effective for noninvasive assessment of skin microcirculation during orthostatic stress.
• Changes in blood volume, flow, and spectral patterns provide insights into the mechanisms of orthostatic intolerance.
• This method holds potential for monitoring cardiovascular adaptation in various physiological and clinical settings.