Sleep apnoea is a common sleep disorder in which the upper airway is repeatedly (partially) blocked during sleep. These breathing interruptions lead to reduced oxygen uptake in the blood. Patients who have suffered a stroke are at increased risk: they often experience poorer sleep quality and are more likely to suffer from sleep disorders such as insomnia and breathing problems.
It is estimated that more than 50 per cent of people experience sleep apnoea after a stroke. However, access to sleep studies is limited. Due to multiple health problems, traditional diagnostic methods, such as polysomnography, are often burdensome, complex and costly for this patient group.
Innovative solution
Researchers at the Institute for Bioengineering of Catalonia (IBEC), in collaboration with the Guttmann Institute, have developed an innovative solution: a smartphone-based system for the early detection and monitoring of sleep apnoea in stroke patients. This is the first application of this technology specifically for this target group.
The research was led by Raimon Jané, professor at the UPC and principal investigator at IBEC and CIBER-BBN. The results have been published in the scientific journal IEEE Transactions on Neural Systems and Rehabilitation Engineering.
Digital biomarkers
Due to the limited availability of polysomnography, the smartphone offers an accessible and mobile alternative. The new system uses built-in smartphone sensors in combination with a wireless pulse oximeter. Acoustic signals, movement and oxygen saturation are measured during the night. Based on this, so-called multimodal digital biomarkers are derived, which provide insight into breathing, body posture and oxygen uptake.
According to Jané, this approach can make an important contribution to healthcare: ‘By integrating digital biomarkers from smartphones, we are improving the detection, understanding and treatment of sleep apnoea after a stroke. This can reduce the clinical impact and support functional recovery.’
High prevalence in stroke patients
The study involved 30 patients in the subacute phase after a stroke, as well as 30 control subjects without stroke (17 men and 13 women) aged between 33 and 63. The results show that 67 per cent of stroke patients had moderate to severe sleep apnoea, compared to 40 per cent in the control group. Severe sleep apnoea occurred in 40 per cent of stroke patients, compared to only 7 per cent of the control group.
In addition, the researchers observed that stroke patients were more likely to breathe through their mouths and sleep on their backs. These factors increase the risk of airway obstruction and exacerbate sleep apnoea.
Application in clinical and home settings
The researchers expect this technology to pave the way for a simple, accessible and portable solution for sleep monitoring, both in clinical practice and at home. This can provide valuable insights, particularly in the early stages of rehabilitation after a stroke.
The study highlights the potential of mobile technology to democratise sleep diagnostics and enable more personalised care for neurological patients, a development that is well aligned with the digital transformation of healthcare.
