High-density surface electromyography: A visualization method of laryngeal muscle activity

Area of Science:

• Biomechanics
• Neurophysiology
• Medical instrumentation

Background:

• Laryngeal muscle activation is complex and dynamic.
• Current evaluation methods like needle and surface electromyography (sEMG) have limitations.
• Needle EMG causes discomfort and has limited recording duration.
• Standard sEMG struggles with spatial selectivity.

Purpose of the Study:

• To evaluate high-density sEMG (HD sEMG) arrays for laryngeal muscle activity monitoring.
• To assess HD sEMG's potential to overcome spatial selectivity loss in sEMG.
• To retain the benefits of noninvasive monitoring while improving spatial resolution.

Main Methods:

• Ten adults performed phonatory tasks (rest, low-pitch, high-pitch).
• A 20-channel HD sEMG array recorded anterior neck muscle activity.
• Data included spatiotemporal information and spectral power per electrode.
• Two-dimensional spectral energy maps were created for muscle identification.

Main Results:

• Significant differences in spectral power were observed across electrodes and phonatory tasks (P < .001).
• HD sEMG detected distinct muscle activity patterns during rest, low-, and high-pitch phonation.
• 2D energy maps enabled gross identification of the cricothyroid muscle.

Conclusions:

• HD sEMG can differentiate anterior neck muscle activity during various phonation tasks.
• HD sEMG of the anterior neck shows potential for improved diagnostic and therapeutic monitoring.
• This noninvasive method may enhance the evaluation of laryngeal function pathologies.