Screening and diagnosis | ResMed

Screening and diagnosis

ResMed is committed to sharing its in-depth knowledge of obstructive sleep apnoea (OSA) screening.

If your patient displays symptoms of sleep-disordered breathing, we can help you accurately refer your patient for an OSA diagnosis.

Diagnosis: key steps


Recognise and identify common symptoms of obstructive sleep apnoea (OSA).


Ask your patient to undergo a sleep apnoea screening test by completing a symptom questionnaire or by using a home sleep screening device.


Based on the results of the screening, recommend a sleep study for your patient to monitor and determine the severity of his or her OSA.

All about sleep studies

Sleep studies should be performed in the patient’s home or at a sleep clinic, in line with local rules and regulations.

During a sleep study, your patient’s breathing, body movements and responses during the night are monitored to see if they have a sleep disorder such as sleep apnoea.

Below is some information you can pass on to your patients about what happens during a sleep study.

Home sleep testing devices

Home sleep testing is made easy with our compact and reliable1 testing devices. Learn more about the following solutions: ApneaLink Air, our compact home sleep testing device and Nox T3s, a portable respiratory sleep monitor.

Sleep study at home

There are two types of set-up for a home sleep study

Home set-up sleep test

  • This test can be conducted using Nox T3s. A home set-up is similar to those in a clinic, hospital or sleep lab – with the added comfort and convenience of being in the patient’s own home.
  • After the night test is completed, the patient returns the recording device to the clinic, hospital or sleep lab. The study data can then be analyzed further with the Noxturnal software, to then provide a report with results.

Home set-up sleep screening

  • A sleep screening study can be performed using ResMed’s ApneaLink Air, a compact, lightweight and easy-to-use home sleep testing device.
  • Your patient’s results can then be further analysed the next day at a clinic, hospital or sleep lab. The ApneaLink Air report provides detailed signal analysis.
  • The results from ResMed home sleep testing devices are compatible with AirView™*, a comprehensive diagnostic software solution for sleep facilities. When used with AirView, ApneaLink Air helps to streamline the workflow while improving collaboration across different locations and various clinical users.

Sleep study in a clinic

During this type of study conducted with the polysomnograph device Nox A1s, your patient will be required to stay overnight at the facility. Therefore, they should take everything needed for their usual sleeping routine, including pyjamas and toiletries.

The test with the Nox A1s polysomnograph can also be performed at home.

Learn more about the Nox A1s, a compact, accurate2 and easy-to-use polysomnograph system.

Equipment of a sleep study in a clinic

In a clinic, hospital or sleep lab, clinical staff will place sensors on your patient’s body to monitor their sleep.

Sensors are placed:

  • On the chest to monitor heart activity;
  • Close to the eyelids to measure eye movements that help indicate if the patient is in REM or non-REM sleep;
  • On the head to measure electrical signals from the brain;
  • On the legs to assess muscle activity.

Patients will also be fitted with:

  • A nasal cannula to monitor breathing;
  • An oximeter on their finger to record oxygen levels;
  • Bands around their chest and stomach to measure breathing effort.

What do sleep studies measure?

Among other things, the sleep study will indicate the severity of your patient’s condition, which is classified using the apnoea/hypopnea index (AHI).

The AHI score indicates the number of apnoeas and hypopneas your patient has per hour (<5 to 30+).3

Severity AHI (per hour)
Normal <5
Mild 5 to <15
Moderate 15 to <30
Severe 30+

In addition to the patient’s AHI, the diagnosis will take into account the patient’s oxygen desaturation and in case of OSA, excessive daytime sleepiness.

Once you receive your patient’s sleep study results, you can then talk to him or her about the condition (if it’s present), its severity, its possible health effects and  treatment options.

More about sleep-disordered breathing

The first sign of a sleep disorder is snoring, even though many patients won’t identify that as a sign of something more serious. There are other common symptoms too. 


Read more

There are three types of sleep apnoea: Obstructive Sleep Apnoea (OSA), Central Sleep Apnoea (CSA) and mixed or complex sleep apnoea. Each type has distinctive characteristics that enable diagnosis. 

Read more

When left untreated, patients with sleep-disordered breathing (SDB) like OSA and CSA have an increased risk of developing serious chronic diseases such as cardiovascular disease, and type 2 diabetes. A significant number of patients with COPD also have SDB. 

Read more

This content is intended for health professionals only.

* AirView was built to be secure and compliant with (EU) 2016/679 (General Data Protection Regulation) and national privacy laws. It uses data encryption technologies to secure patient data. ResMed security specialists are heavily involved in AirView, from the initial design to ongoing monitoring of operations. The solution is regularly tested for risk management and privacy compliance. Our hosting provider in Europe is a third-party company that holds the stringent HDS (Hébergement de Données de Santé) certification as well as ISO 27001 certification to host medical data.


  1. ApneaLink Air: Kapur, V.K. et al., 2017. Clinical practice guideline for diagnostic testing for adult obstructive sleep apnea: An American academy of sleep medicine clinical practice guideline. Journal of Clinical Sleep Medicine 2017; 13(3): 479-504; DOI:10.5664/jcsm.6506
  2. Yoon, IH Hong, I Baik, HW Shin. Evaluation of the feasibility and preference of Nox-A1 type 2 ambulatory device for unattended home sleep test: a randomized crossover study. Sleep and Biological Rhythms, 2019; 17: 297–304; DOI: 10.1007/s41105-019-00213-4
  3. American Academy of Sleep Medicine, Sleep-related breathing disorders in adults: recommendations for syndrome definition and measurement techniques in clinical research. The Report of an American Academy of Sleep Medicine Task Force. Sleep, 1999. 22(5): p.667-89; DOI: 10.1093/sleep/22.5.667