HypnoLighT: an innovative feature for diagnosing sleep apnoea
Apnoea-hypopnoea syndrome (OSAHS) is one of the most common sleep disorders, affecting between 2% and 5% of the adult population in France, i.e. between 1 and 3 million individuals (data from the French National Authority for Health).
One way of estimating the severity of this disorder is to use the apnoea-hypopnoea index (AHI), which can be assessed during a respiratory polygraph examination. However, the lack of information about the patient’s actual sleep time may lead to an underestimation of the AHI.
That’s where HypnoLighT comes in: an innovative feature developed by CIDELEC that provides advanced polygraphy and a more relevant diagnosis of sleep breathing disorders.
The limit of respiratory polygraph in AHI
Respiratory polygraphy is often recommended as a first-line treatment when sleep breathing disorders are suspected in a patient. This examination, which explores different respiratory characteristics during sleep, has the advantage of being able to be carried out in ideal conditions (at the patient’s home), even if the equipment has to be installed by a practitioner beforehand.
However, this examination has one drawback: the recording time does not take into account the patient’s actual sleep. In other words, the test takes place without it being known whether or not the patient is asleep, at what time, or for how long. This lack of information is likely to underestimate the results of the AHI, which is calculated on the basis of the number of respiratory events in relation to the recording time, and not on the basis of total sleep time.
How can a proper diagnosis of sleep apnoea be made if one can’t be sure that the patient is actually sleeping? This is where HypnoLighT comes in.
The role of HypnoLighT in the diagnosis of sleep apnoea
Until now, only polysomnography has been able to distinguish between phases of sleep and wakefulness in patients. But this comprehensive examination is also more complex, since it often has to be carried out in a clinic or laboratory, in the presence of a specialist technician, and is accompanied by heavy equipment. CIDELEC designed HypnoLighT precisely to meet this challenge: to provide information on sleep duration in order to improve the sensitivity of respiratory polygraphy.
HypnoLighT is an algorithm that supports polygraph examination by helping to distinguish between sleep and wakefulness in patients. The apnoea-hypopnoea index is calculated on the basis of the number of respiratory events in relation to the estimated sleep time, enabling a more accurate and relevant diagnosis to be made. This is done during an examination that is simple to set up: just two light sensors to place. In comparison, polysomnography requires around fifteen electrodes, including in difficult areas such as the scalp.
HypnoLighT technology : a major step forward for sleep specialists
HypnoLighT technology makes it possible to bring respiratory polygraphy closer to polysomnography, and to diagnose sleep apnoea more effectively by calculating the AHI more accurately. It is compatible with CIDELEC’s CID-LXa device, an ergonomic, lightweight polygraph that is placed on the wrist.
Entirely developed and manufactured in France, HypnoLighT represents a major step forward in the diagnosis of sleep disorders. Its benefits are backed up by scientific studies (several references to which can be found on this page).
For example, the average rate of agreement between awake vs. asleep discriminations obtained by this functionality and by a specialist’s rating is over 85%, while the average rate of agreement between two clinicians for polysomnography is around 90%. Our studies have shown that among patients whose diagnosis is underestimated using respiratory polygraphy, a third would have been correctly diagnosed using HypnoLighT. For the latter, it is no longer necessary to perform a second-line polysomnography and the most appropriate treatment can be proposed to the patient.
