Repeatability and stability of photoplethysmography measurements of muscle blood flow in musculus orbicularis oculi

摘要

Visual discomfort is a common symptom among computer users (Helland, Horgen, Kvikstad, Garthus, & Aar(a)s, 2008) and may be related to increased muscle strain in the muscles surrounding the eye. During work situations where the eyes were stressed by excessive lighting and use of small font, electromyographic (EMG) response in m. orbicularis oculi was raised (Gowrisankaran, Sheedy, & Hayes, 2007; Niru, Sheedy, Hayes, & Yu-Chi, 2007). The function of m. orbicularis oculi is to mediate voluntary blinking and/or squinting of the eyes. Visual discomfort and increased muscle tension in m. orbicularis oculi during visually demanding work may be related to changes in muscle blood flow (Yasuda, Brechue, Fujita, Shirakawa, Sato, & Abe, 2009). The aims of this study were to evaluate validity and reliability of muscle blood flow measurements in m. orbicularis oculi using a new application of photoplethysmography (PPG).