Types of Sleep Tests

Sleep testing, or polysomnography (PSG), according to international medical standards (AASM), is divided into four main types (Type 1-4), ranked according to the sophistication of the equipment and the testing location, as follows:

​

Type 1: Full Attended In-Lab PSG (Full Attended In-Lab Monitoring)

• Operation: This is the most detailed and accurate test (Gold Standard), requiring the patient to stay overnight at a hospital or specialized clinic, where staff monitor their symptoms throughout the night via monitors.

• Recorded indicators: More than 7 channels are monitored, including brainwave activity (EEG), electrocardiogram (ECG), eye and jaw muscle movements, breathing, chest and abdominal movements, blood oxygen levels, and sleeping posture.

• Suitable for: Those who need to be diagnosed with any form of sleep disorder, such as obstructive sleep apnea (OSA), restless leg syndrome (PLMD), or disruptive sleep and severe nightmares.

​

Type 2: Unattended Full PSG (Full System Monitoring Outside the Office)

• Operation: The equipment and number of sensor wires attached are identical to Type 1 (recording brainwaves and various electrical signals completely), but the difference is that there is no staff member present overnight during the examination. Patients usually have the equipment attached at the hospital in the evening and then return home to sleep.

• Suitable for: For those who have no problem staying in an unfamiliar place, or those who require high accuracy but are unable to stay overnight at the hospital.

​

Type 3: Respiratory system screening (Home Sleep Apnea Testing - HSAT)

• Operation: This test focuses primarily on examining the respiratory system, reducing the number of lines to approximately 4–7 channels. The device is more compact and can be easily installed and used for home testing.

• Recorded indicators: Breathing, chest/abdominal movement, blood oxygen levels, and heart rate are monitored (brain waves are not measured, so the precise depth of sleep is unknown).

• Suitable for: Individuals at high risk for obstructive sleep apnea (OSA) include those who snore loudly, wake up suddenly to aspirate water, and do not have other serious underlying medical conditions.

​​

Type 4: Initial screening (Continuous single or dual bioparameter)

• Operation: Only one or two vital signs are monitored, most commonly using a pulse oximeter to continuously record readings throughout the night to see if there are periods of oxygen drop due to apnea.

• Suitable for: It is used as a very initial screening step or to monitor treatment outcomes in cases where symptoms are clearly known. It cannot be used to confirm a 100% diagnosis.

​​