What is the role of thermistors in sleep studies?

Thermistors play an essential role in sleep studies by measuring airflow. These devices are sensitive temperature sensors that can detect changes in temperature that occur as a result of airflow. During a sleep study, they are typically placed at the nostrils or mouth to record the temperature of inhaled and exhaled air. The variations in temperature correlated with the airflow help in identifying respiratory events such as apneas or hypopneas. Recognizing these events is crucial for diagnosing sleep disorders like obstructive sleep apnea.

The other options, while relevant to various components of sleep studies, are not related to the function of thermistors specifically. Brain activity is evaluated using electroencephalography (EEG), heart rhythms are monitored with electrocardiography (ECG), and body temperature is usually assessed with different types of temperature sensors or thermocouples, rather than thermistors.