Also known as Delta Activity. Diagnostic Sleep Study - Continuous monitoring of several physiological activities in a sleeping individual. Usually carried out to determine the absence or presence of a specific sleep disorder. A diagnostic sleep study can be performed in a sleep disorders center or in a patient's home with portable recording equipment. Inhalation occurs when the diaphragm contracts.
Exhalation is usually passive as the muscle relaxes.
Diurnal - Active and wakeful in the daytime, as opposed to active in the nighttime. This includes CPAP and Bi-Level machines. Drowsiness, Drowsy - A state of quiet wakefulness that typically occurs prior to sleep onset. If the eyes are closed, diffuse and slowed alpha activity usually is present, which then gives way to early features of stage 1 sleep. Dyssomnias - A class of sleep disorders that produce either insomnia or excessive sleepiness.