Home Sleep’s level 2 sleep studies accurately measure your sleep and breathing using the same techniques and technology found in a hospital study to diagnose sleep-related breathing disorders such as obstructive sleep apnoea.
We measure:
- brain waves,
- eye movement and
- jaw muscle activity
which allows one of our trained sleep scientists to assess when you are asleep, what stage of sleep you are in, when you are waking and look for any signs of sleep-related bruxism (teeth grinding/clenching).
We also look at all important respiratory signals to see if there are any breathing issues during your sleep.
- Two respiratory bands around your torso measure your chest and stomach movement,
- a nasal cannula measures your actual breathing and
- a pulse oximeter measures blood oxygen levels.
The analysing sleep scientist will look at these signals and mark whenever they see a reduction in breathing that causes you to either wake up or your blood oxygen levels to drop by at least 3%, this is known as a respiratory event. We can judge if a respiratory event is caused by an upper airway obstruction, because there will still be respiratory effort in the respiratory bands, or if it is a pause in the respiratory drive, as the respiratory band signals will flatten. We can also determine the type any obstruction is, based on if the airway is only narrowing (hypopnea), or if it completely closes over (apnoea). Severity of sleep apnoea is based on the average amount of respiratory events per hour of sleep and the degree of blood oxygen desaturation as a result of the respiratory events. Many people will have these respiratory events waking themselves up hundreds of times during the night without realising it, because most of the time you’re only waking for 3-10 seconds, not long enough to be aware.
Sleep apnoea often differs in severity throughout the night due to differing circumstances. Because we can see sleep stages, we can determine if any sleep apnoea is worse or even isolated to specific times during your sleep. A position sensor in the recording unit that you wear on your chest tells us if you are sleeping on your back, side or front, showing if sleep apnoea is, as it is for many people, worse when you are lying on your back.
We can also measure leg movements through the night, mainly to look for what’s known as Periodic Limb Movement Disorder (PLMD), which is when the limbs (almost always the legs) periodically twitch during the night, interrupting your sleep in the same way that respiratory events do, but without the risk of blood oxygen desaturations.
Our sleep study also has a dedicated channel measuring your heartbeat, a useful screening tool for any irregular beats that we can highlight for you and your doctor.