Monitoring the motor cortex hemodynamic response function in freely moving walking subjects: a time-domain fNIRS...

Area of Science:

• Neuroscience
• Biomedical Engineering
• Motor Control

Background:

• Gait dysfunctions require reliable monitoring tools.
• Noninvasive methods for assessing motor cortex activity during natural movement are needed.

Purpose of the Study:

• To pilot the use of time-domain functional near-infrared spectroscopy (TD fNIRS) for monitoring motor cortex hemodynamic response function (HRF) during free walking.
• To investigate differences in motor cortex activation between forward and backward walking.

Main Methods:

• A wearable, single-channel TD fNIRS oximeter was used to monitor the lower limb motor cortex in three healthy subjects.
• Subjects performed forward and backward walking tasks, and data was compared to a finger-tapping task to rule out motion artifacts.

Main Results:

• Hemodynamic changes (oxygenated and deoxygenated hemoglobin) were measured during walking.
• Adaptive HRF fitting revealed greater motor cortex involvement during backward walking compared to forward walking.
• Motion artifacts were excluded as a confounding factor.

Conclusions:

• This study demonstrates the feasibility of using TD fNIRS to measure hemodynamic motor cortex responses during natural walking for the first time.
• Observed differences in cortical responses between forward and backward walking suggest varying motor cortex engagement.
• TD fNIRS shows promise as a noninvasive tool for gait dysfunction monitoring.