Polysomnography (PSG) is the most common form of sleep apnea testing – your breathing pattern and other bodily functions receive steady monitoring and recording. Sleep apnea testing monitors heart rate, state of sleep, levels of oxygen in the blood, any difficulty in breathing, eye movement and muscle activity.
There are 2 kinds of PSG tests. Testing overnight in sleep study centres or hospitals which means the patient while sleeping or in some instances PSG might be performed at home with help from a special monitor, and a sleep specialist to hook up the machine.
During overnight testing the following monitoring is generally undertaken:
Surface electrodes: A vital part of a sleep study is understanding what has happened while you are sleeping. When electrodes are attached to your body, the recorded electrical signals generated by your brain and muscle activity are kept track of.
Electroencephalogram (EEG) :EEG is a major area of sleep apnea testing as it measures different sorts of brain activity.
Electromyogram (EMG): A graphical tracing of the electric activity in a muscle at rest or during contraction, used to diagnose nerve and muscle problems. EMG also helps to recognize REM (rapid eye movement) which is critical as sleep apnea is often worse during REM sleep.
Electro-oculogram (EOG) : EOG is a record of the difference in electrical charge between the front and back of the eye that’s interrelated with eyeball movement (as in REM sleep) – helps recognise stages of sleep.
Electrocardiogram (EKG or ECG) : An electrocardiogram is a test that checks for problems with the electrical activity of your heart. It interprets the heart’s electric activity into line tracings on paper. The spikes and dips in the line tracings are known as waves.
Nasal Airflow Sensor : A method and related system to ascertain nasal resistance to airflow.
Oximeter : A heart beat oximeter monitors and records airflow and breathing patterns. Most monitors also show the heart rate. If a patient has apnea, test results will show a rise and fall in their blood oxygen levels, a fall while asleep and a rise on waking.
Visible recording to track body movements and positions.
Snoring Monitor.
While the above may appear to be quite complicated your sleep expert will be able to explain the way in which the monitoring works in full detail.
After going through sleep apnea symptoms for a few years the writer, Peter Patterson, undertook sleep apnea testing to diagnose his health condition. Part of his testing involved undertaking a sleep apnea polysomnology study. His web site explains material which relates to every aspect of this sleeping problem.
