If your doctor suspects you have sleep apnea or another sleep disorder, he or she may prescribe a sleep study in one of our sleep labs. You'll typically arrive at the sleep lab in the early evening and leave the next morning. We provide a natural sleeping environment with hotel-like accommodations, so you'll have your own comfortable, private room.
The sleep study, also called a polysomnogram, records brain activity, eye movement, oxygen and carbon dioxide blood levels, heart rate and rhythm, breathing rate and rhythm, the flow of air through your mouth and nose, snoring, body muscle movements, and chest and belly movement. The results are used to determine if you have one or more of the 80 sleep disorders that can interfere with your good night's sleep.
A range of sensors
Prior to beginning the study, the technician will fit you with the sensors listed below. You may feel like a "bionic" person with all these wires attached to you, but most patients find they are able to sleep normally.
- An oximeter to measure how your blood oxygen levels change during sleep (blood oxygen levels decrease during apnea episodes)
- Electromyography (EMG) to measure the activity of the muscle groups around your chin, lower leg (tibia) and eyes
- Electrooculography (EOG) to measure eye movement, which are slower when you are in rapid eye movement sleep (REM sleep)
- Electrocardiography (EKG, ECG) to measure the electrical activity of your heart
- Electroencephalography (EEG) to measure brain wave activity to determine the different stages of sleep. Brain wave patterns also can be used to tell when you are in REM sleep
- Chest plethysmography to measure chest wall movements, which shows when you are taking a breath
- In addition, a video camera records how long it takes you to fall asleep and monitors your body movements during sleep.
CPAP Study for Sleep Apnea
If moderate to severe obstructive sleep apnea is diagnosed during the sleep study, a continuous positive airway pressure or CPAP study is often recommended. During this study, you're fitted with a nasal mask or a full-face mask that covers both your nose and mouth and is connected by a flexible tube to a small air compressor. The machine's fan gently pushes air through the tube, into the mask and down the back of your throat. The pressure level on the CPAP machine is started low and is gradually increased to find the right level of air pressure that will prevent the collapse of your airway during sleep.