Overnight, Attended Sleep Study

The Stanford Sleep Disorders Clinic is a state-of-the-art facility located in Redwood City. We run sleep  studies six nights per week and our knowledgeable team of sleep techs can monitor up to 18 patients per night.

Overnight, attended sleep studies –known as nocturnal polysomnograms (PSG)– are conducted in a sleep lab where you’re monitored (or attended) all night by a trained sleep technologist. Your doctor may recommend a sleep study to diagnose or rule out a sleep disorder such as obstructive sleep apnea, narcolepsy or periodic limb movement disorder. You may also undergo a sleep study if you've already been diagnosed with a sleep disorder so that we can create or adjust your treatment plan.

During the study, we assess your sleep stages by recording brainwaves (EEG), eye movements (EOG) and muscle tone (EMG). We also carefully examine your breathing throughout the night by measuring your airflow, breathing effort, snoring and oxygen saturation. Leg movements and heart rate (ECG) are also monitored to provide a comprehensive evaluation of your sleep.

Collecting all this data requires the sleep technologist to apply numerous sensors before you go to sleep. The set up procedure is quite complex and usually takes about 90 minutes. The hook up includes applying sensors on the scalp, face, throat, chest, finger and legs.

There are three common types of overnight sleep studies:

Diagnostic Evaluation: This study measures your sleep without any intervention. It’s typically used to diagnose or rule out a disorder.

Continuous Positive Airway Pressure (CPAP) Titration: During a CPAP titration, the technologist adjusts the setting on the CPAP machine to determine how much air pressure is needed to normalize your breathing.

Split Night Study:  A split night study is a combination of a diagnostic and CPAP titration study. The first half is used to diagnose sleep apnea and then midway through the night CPAP is started. The sleep tech spends the rest of the night adjusting the pressure until breathing has been normalized.

How to prepare for your overnight sleep study

An overnight sleep study, also called a polysomnogram, is a procedure which monitors body functions such as brain waves, heart rate, leg movements and breathing during sleep. You will be monitored by a sleep technologist all night long. There are different types of sleep studies.  Diagnostic studies are used to evaluate whether you have a sleep disorder.  A CPAP (a mask worn over the nose) study is performed to determine the ideal pressure settings. 

A technologist will greet you at approximately 7:00 pm in the waiting area of the lab and will show you to your bedroom. It is important that you arrive on time!  Be sure to eat before you arrive.

Once you are settled in your bedroom, you will change into your bedclothes and complete some paperwork.  Then the sleep technologist will apply electrodes and sensors which takes about an hour.  Sensor attachment will be done utilizing collodion (a glue-like substance) and medical tape.  Please prepare for this process by thoroughly washing your hair before your visit to our lab.  After the sensors are in place, you will be able to walk around the bedroom and use the restroom unassisted.

You may go to sleep at your normal bedtime within the constraints of the lab protocols.  Keep in mind, the earlier you go to bed, the more time we have to evaluate your sleep.  Some patients will use CPAP during the night.

During the night, a technologist will be available to assist you as needed.

Typically, we begin waking patients at 6 am, unless a later or earlier wake up time is desirable. Please keep in mind that the equipment takes approximately 20 minutes to remove.

There is a shower available to wash up after all of the sensors have been removed.

Our Clinic

Learn more about the Stanford approach by visiting the Sleep Medicine Center
Call 650-723-6601 to make an appointment