Kettering Polysomnography (PSG) Practice Test 2026 - Free PSG Practice Questions and Study Guide

To calculate the total sleep time (TST) for the patient, the formula used is:

**TST = Time in Bed (TIB) - Sleep Onset Latency - Wake After Sleep Onset (WASO)**

First, we take the time in bed, which is 380 minutes. Then, we subtract the sleep onset latency of 30 minutes, representing the time taken to fall asleep. This gives us:

380 minutes - 30 minutes = 350 minutes.

Next, we need to account for the time spent awake after the patient has fallen asleep, referred to as wake after sleep onset (WASO), which is 34 minutes. Therefore, the calculation continues as follows:

350 minutes - 34 minutes = 316 minutes.

This derived total of 316 minutes represents the patient's total sleep time (TST). Therefore, the correct answer is 316 minutes, as it accurately reflects the amount of time the patient actually spent asleep during the designated sleep period.