Which of the following is NOT a primary purpose of the EOG channel?

The primary purpose of the EOG (electrooculogram) channel is to measure eye movements, which can be critical in assessing various aspects of sleep. Eye movements are particularly important in identifying different sleep stages, such as REM (Rapid Eye Movement) sleep, where eye movements are typically prominent.

Monitoring arousals is also facilitated through the interpretation of EOG data, as changes in eye movement patterns can indicate whether a patient is transitioning between sleep stages or experiencing disturbances. Therefore, the EOG contributes significantly to the understanding of sleep architecture.

In contrast, monitoring heart rate is not a function of the EOG channel. Heart rate is typically assessed using an ECG (electrocardiogram) or pulse oximetry. These methods focus specifically on the heart's electrical activity or blood oxygen levels, rather than eye movements or sleep stage transitions. Thus, the EOG channel does not serve to monitor heart rate, distinguishing it from the other options related to the primary functionalities of the EOG.