What is the difference between polysomnography and polygraphy?

Polygraphy (PG), or ambulant sleep apnea recording, is a common method for diagnosing obstructive sleep apnea (OSA) because it is easy to use and cost-effective [1]. However, PG does not measure sleep as polysomnography (PSG) with EEG, EOG, and EMG does, thus the arousals caused by flow limitation and not shown sleep stage.

Polygraph (PG)

To detect obstructive sleep apnea (OSA), these two type of sleep studies can be conducted:Polysomnography (PSG) and Polygraphy (PG).

Polygraphy (PG): Home Sleep Apnea Test (HAST), this second type of study involves using a portable device at home to detect OSA.

Advantages of Polygraphy:

Convenience: unlike PSG, where you need an appointment with a technician, RP allows you to pick up the device and perform measurements at your convenience.

Ease of Installation: the devices are straightforward to set up.

Comfort: You get to sleep in your own bed during the test.

Cost-Effective: PG is more budget-friendly; its cost can be half that of a polysomnogram.

Effective for Obstructive Sleep Apnea Diagnosis: PG serves as a reliable test for diagnosing obstructive sleep apnea.

If you experience symptoms such as loud snoring, waking up in the middle of the night, fatigue, and daytime drowsiness, it’s essential to consult a specialist for examination. Depending on your doctor’s assessment, you may be prescribed a respiratory polygraph.

When prescribed a respiratory polygraph, patients receive a measuring device from their doctor’s office or a sleep clinic. Alternatively, a sleep technician may bring the device directly to the patient’s home. Patients follow the technician’s instructions on how to set up and use the device.Then, patients wear the device while sleeping. The device collects data related to breathing patterns, oxygen levels, and other relevant parameters. An additional sensor is attached to the body to monitor chest and abdominal movements during breathing. The device records various signals throughout the night, including airflow through the nose, oxygen saturation (SpO2), and snoring sounds. Patients can rest assured that the device won’t significantly disrupt their sleep.

The following day, patients return the device. Technicians and sleep specialists analyze the collected data. The primary goal is to detect obstructive sleep apnea (OSA) and assess overall sleep quality.

Polysomnography (PSG)

To detect obstructive sleep apnea (OSA), these two type of sleep studies can be conducted: Polysomnography (PSG) and Polygraphy (PG).

Polysomnography:This overnight sleep study, conducted in a Sleep Lab or Hospital, is the gold standard for diagnosing obstructive sleep apnea (OSA). Polysomnography, also called a sleep study, is a comprehensive test used to diagnose sleep disorders. Polysomnography records your brain waves, the oxygen level in your blood, heart rate and breathing, as well as eye and leg movements during the study,According to record above parameters could find the patient’s sleeping problems, and diagnose type of apnea, severity of apnea, analyze the effectiveness of sleep disorders therapy, PSG is the " gold standard " for diagnosis of OSA and other forms of sleep-disordered breathing. PSG is an painless, safe diagnostic device.

The components of a polysomnogram include the following:

● Electroencephalogram (EEG)

● Electromyography (EMG)

● Electro-occulogram (EOG), to monitor for rapid eye movements

● Electrocardiogram (ECG), to monitor cardiac function

●Oral and nasal airflow pressure and temperature (using nasal pressure transducer and thermistor)

● Chest and abdomen movement (i.e. - respiratory effort, measured using chest and abdominal belts)

● Oxygen saturation (using finger probe digital pulse oximetry)

● Transcutaneous CO2 (TcCO2)

During PSG, characteristic EEG, EMG, and EOG amplitudes and waveforms are scored in 30 second epochs.Ventmed brand's PSG is complies with the latest version of AASM standard, use AI technical analysis for the reports, also could generate multiple reports, effectiveness of sleep disorders therapy.