Hi, I'm Shawn Kimbro, welcome to my sleep page.  I am a registered polysomnographic technologist (RPSGT).  Polysomnography is the scientific evaluation of sleep. Sleep studies are accomplished using a polysomnograph. On this page I'd like to tell you a little about sleep studies and why we do them.

A polysomnograph is a machine that converts electrical impulses in the body to a graphical representation which can help determine what's happening as we sleep. Many different activities  are monitored by the polysomnograph during a sleep  study. These include brain waves (EEG), eye movements (EOG), muscle activity (EMG), heartbeat (EKG), blood oxygen levels (SpO2) and respiration. Each of these activities is represented by graphical tracings on a polysomnogram. Since the tracings go on throughout the night during sleep, they can be over a thousand pages in length.      


Since not all sleep centers work the same, it's important to choose wisely when selecting a sleep center.  Many sleep centers are located in hospitals, but the current national trend is toward independent, free-standing sleep testing facilities directed by board certified sleep physicians.  These independent facilities  generally provide a high  standard of care at prices less than half of what hospitals charge. Distractions are minimized and you sleep in a quiet and comfortable neighborhood testing environment. Not all patients who come to a sleep center need a sleep study. It's up to a doctor to decide who should have their sleep evaluated. Sleep Centers that have a full-time sleep physician who is board certified as a specialist in sleep medicine (a diplomate of the American Board of Sleep Medicine ) are  the best at selecting patients for sleep studies and interpreting results. Always ask if the center's medical director is board certified in sleep before you go. Most of the questions I receive from this web site come from people who make the mistake of omitting this step.  Always ask first!  You should speak to this doctor before and after your sleep study.  Another important step is to look for a center that employs registered sleep techs (RPSGTs) .  Since sleep medicine is such a specialized field, it's not enough to just employ respiratory therapists or neuro techs.  RPSGT certified technologists are specifically trained to insure you get the best of all possible testing. State societies such as the one in Tennessee can help you locate sleep centers with qualified RPSGT certified technologists. You also should make sure the center you choose has a comprehensive follow-up and treatment program.  The testing facility can make all the difference in your health.  Since sleep is a new and growing field, it's important to ask questions and find the best sleep center available.

Sleep Studies

After your doctor orders a sleep study,  you will go to a sleep center and be greeted by a polysomnographic technologist. The tech will show you to a quiet comfortable room where you'll spend the night. The tech will ask you some questions about the events of your day, then begin the "hookup." This procedure is one of the most interesting parts of the night. The tech will place small sensors called electrodes on your scalp, face, chin, chest, and legs. The process isn't painful at all and takes only about thirty minutes. The question everyone asks is, "Do you really expect me to sleep in all this?" Surprisingly, most people have little difficulty going to sleep wearing all the wires and sensors. After you are hooked up, you'll have some time to go back to your room and relax before the test begins. During this time the tech may be hooking up another patient or performing calibrations on the equipment. The test will probably begin around the time you normally go to bed.

During the night

Once the test begins the polysomnograph will reveal just when drowsiness ends and sleep begins. Normally this only takes a few minutes. Sleep researchers divide sleep into stages. Stages 1-4 indicate progressive degrees of sleep with stage 1 being the lightest and stage 4 being very deep sleep. Usually after about 90 minutes we have progressed  through all 4 stages, then we enter REM  sleep. This is the stage of sleep when most people dream. On the polysomnograph it looks surprisingly like wake with the main difference being that there is an attenuation of muscle tone. Stage REM is usually very short early in the night. But we repeat the cycle of sleep stages and the length of REM periods gradually increase as the night goes on. By the time morning rolls around, we are in REM most of the time. Researchers have found we need a good mix of all sleep stages in order to wake up feeling refreshed and rested .

Sleep Disorders

In addition to monitoring sleep stages, the technologist is carefully observing the patient's breathing. Many patients we test in our sleep center suffer from  obstructive sleep apnea , a condition caused by excessive soft tissue in the airway. A person who has sleep apnea may stop breathing hundreds of times during the night. Apnea can have very serious consequences if left untreated, including an increased risk of heart failure and stroke.  Anyone can have sleep apnea, it's not just present in the very obese. Fortunately, it is very treatable by methods such as continuous positive airway pressure (CPAP) or mandibular advancement devices. Other disorders treated in the sleep center include restless leg syndrome (RLS) , periodic limb movement disorder (PLMD) , narcolepsy , and of course insomnia. There are many other disorders that can seriously affect a person's sleep and daytime productivity.  Nearly 100 have been identified. These disorders can be readily apparent to a physician skilled in sleep medicine and interpreting the results of a polysomnograph. If you think you may have a sleep disorder you might want to take this simple test . For the latest information and most current news about sleep disorders, visit SLEEPSCIENCE,  my weblog:  http://sleepscience.blogspot.com/

Insurance

  If you have any questions about sleep disorders and polysomnography, or if you think you may have a sleep disorder, contact Shawn .  I'll be happy to answer any questions that I can.  I am also available for educational presentations to schools, civic groups, and professional societies anywhere in the United States or Canada.