Hey all, Thomas E asked what we monitor in a sleep study, so I am putting the information in a blog for him, and anyone else who is interested.

     Tonight I thought I'd let you know what we monitor in a sleep study.  We apply an electrode just to the outer side of each eye, these allow us to see your eye movements, we can tell when the eyes are open closed, reading and dreaming.  Then we attach several electrodes to your head so we can see your brain waves, this allows us to tell when your awake, asleep, and what stage of sleep your are in.  Two or three electrodes are applied to your chin so we can tell when you experience atonia (lack of muscle tone as in paralysis), which indicates you're about to go into REM sleep (or to dream).  We can also see Bruxism which is when you grind your teeth.  A small microphone is attached to your neck, this picks up vibration and allows us to see if you snore.  There is a thermistor and a pressure transducer, a very small piece of equipment like an oxygen canula placed in your nostrals just like oxygen would be to show us when you are breathing in and out through the nose and mouth.  All of these little electrodes have wires, which we gather onto the top of your head and place in a ponytail, allowing you free movement and keeping you from becoming tangled.  Two or three electrodes are applied to your chest so we can monitor your heart, we watch heart rate, rhythm, and look for any irregular beats.  Sometimes a sleep study finds more problems with the heart then a stress test.  Two stretchy belts are placed around you one around your chest, one around your abdomen, these belts show us when your chest and abdomen rise and fall as you breathe.  They should not be tight or uncomfortable and they shouldn't be bothersome. Two electrodes are placed on each leg just below the knee to the outer side of the shin on the muscle you feel when you point your toe, then bring your foot up by flexing at the ankle.  These sensors show when you move your toe, foot, or whole leg during the night to look for leg movement disorders.  All of these electrodes are bundled behind your neck, so again you don't get tangled and they stay out of your way.  All of those wire plug into a Headbox which is then plugged into the cable that is connected to the computer.  The head box typically has a strap, so if you need to get up during the night to use the restroom, the tech just unplugs the headbox, and you wear the strap like a purse, it's easy.  Very portable.  There is one more little sensor, it typically goes on your finger, it tells us the amount of oxygenation in your blood.  This allows us to see in real time (well 3 second delay) how much your oxygen levels in your body are affected by sleep or apnea.  Most people have slightly lower oxygen levels when they sleep than when they are awake.  That's why some people need oxygen at night. Oxygen will not fix Apnea.  The technologist doing your study will record on paper the time, page number of the study also known as Epoch number (an epoch is 30 seconds long) oxygen level, stage of sleep, breaths per minute, the position your sleeping in, heart rate, snoring volume, and a comment about behaviors, apnea, leg movements, etc. every 15 minutes throughout the night.  In the morning we write a report stating what we observed for the doctor.  The scoring Technologist then comes in and goes through the study page by page (typically 800-900 pages) and marks every page with the stage of sleep, any irregular heart beats, any apnea, any leg movements, or anything else out of the ordinary this typically takes about 2 hours, then we write a report to the Sleep Physician.  The sleep doctor reads the chart, the scoring techs comments, the recording techs comments, and makes a diagnosis, and recommendations for the patient, that info is then sent to the patients doctor so the patient can be informed of the diagnosis, and recommended treatment plan.  Good luck with your sleep study Thomas, I hope you have a great night and can get some answers to help you feel better.

Michele