Sleep apnea in Evimeria

Posted on 19 January, 2022 by Eva Clergue

Hello everyone!

Today we focus on sleep apnea and hypopnea detection in Evimeria®.

First, what are exactly those sleep respiratory disorders?

According to the National Heart, Lung and Blood Institute in United States (NHLBI), obstructive sleep apnea occurs when the upper airway becomes blocked repeatedly during sleep, reducing or completely stopping airflow. We talk about central sleep apnea if the brain does not send the signals needed to breathe during sleep.

Hypopnea is closely related to sleep apnea and corresponds to 10 seconds or more of shallow breathing (from 30% to 90% of normal airflow’s loss), with a blood oxygen saturation drop of 3% to 4%.

How to measure the importance of sleep apnea?

One common indicator used to evaluate the importance of these sleep disorders is the Apnea-Hypopnea Index (AHI). It corresponds to the number of sleep apnea (and hypopnea) events in one hour of sleep. The following thresholds have been defined to talk about mild, moderate, or severe Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS):

• Mild: AHI between 5 and 14
• Moderate: AHI between 15 and 29
• Severe: AHI greater than 30

What can be sleep apnea consequences?

According to the National Institute of Health and Medical Research (INSERM) in France, the OSAHS affects approximately 5% of the population, 30.5% of people older than 65 are concerned by this syndrome. These figures are probably under-estimated due to the asymptomatic forms of this syndrome and the lack of diagnosis in the population.

Sleep apnea has a direct effect on daily activities like drowsiness, memory, or concentration problems. In the long term, it favors the occurrence of hypertension, coronary artery disease, heart failure, heart rhythm disorders, and strokes.

Apnea and ECG in Evimeria®

In Evimeria®, we propose an algorithm of detection of sleep apnea and hypopnea events, based on a single-lead ECG recorded with the Movesense® sensor. Using heart rate and analyzing heart rate variability, several features can be extracted and used in a machine learning model to classify parts of the ECG as apnea events or not. Thanks to this analysis, we give you a first indication of your number of sleep apnea events and advise you to go see a doctor for further examination if necessary (warning slot).

See you on February 2^nd for another post, this time on sleep stages analyses!

In the meantime, Go Evimeria® & Stay tuned!!!

Some references:

https://www.nhlbi.nih.gov/health-topics/sleep-apnea

https://www.ameli.fr/assure/sante/themes/apnee-sommeil/comprendre-apnee-sommeil

https://www.sleepfoundation.org/sleep-apnea/hypopnea

https://www.inserm.fr/dossier/apnee-sommeil