Ventilatory polygraphy

Nocturnal Ventilatory Polygraphy (NPV) is a simple, painless  sleep medical examination that allows you to record several parameters of your breathing and sleep at home. The test is prescribed by a sleep specialist or pulmonologist.

Nocturnal ventilatory polygraphy : Why ?


Nocturnal ventilation polygraphy is conducted at home to diagnose and/or confirm sleep apnea syndrome (SAHOS), characterized by repeated pauses in breathing during sleep. The test looks for respiratory markers and oxygen levels in the patient’s blood during sleep.

The patient equips himself with two belts (one thoracic and one abdominal) to record respiratory movements, a sensor positioned at the base of the neck to record snoring and breathing sounds, an oximeter to measure oxygen levels in the blood and a nasal cannula to capture airflow.

cenas salledecontrole polysomnographie analyse

Nocturnal ventilatory polygraphy procedure

Fitting the equipment takes around 30 minutes. The device is easy to use, so you can carry out the examination at home in the comfort of your own bedroom. The next morning, unplug the sensors and recorder and return them to the Cenas center.

Setting up your polygraph

Respiratory polygraphy : Analysis and Additionnals examination

The data recorded by the sensors is analyzed by a sleep specialist. The doctor can :

1. Confirm or refute the diagnosis of SAHOS
2. Determine the severity of respiratory problems
3. Identify other sleep disorders
4. Refer to the most appropriate treatment.

The results of the ventilatory polygraphy are used to evaluate the apnea/hypopnea index per hour (AHI):

  • Less than 5: no sleep apnea.
  • Between 5 and 15: light sleep apnea.
  • Between 16 and 30: moderate sleep apnea.
  • Above 30: severe sleep apnea syndrome.

In some cases, the results of ventilatory polygraphy cannot be used because sleep has been too fragmented. This prevents accurate determination of the AHI. In such cases, polysomnography is essential.


Nocturnal ventilatory polygraphy is a useful test for diagnosing sleep disorders, in particular to validate a diagnosis of sleep apnea syndrome and to obtain appropriate treatment.

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