Evaluation of Sleep Apnea in Stroke Patients Using a Portable Smartphone-Based System

Area of Science:

• Neurology
• Biomedical Engineering
• Sleep Medicine

Background:

• Sleep apnea is frequently underdiagnosed in post-stroke patients, negatively impacting rehabilitation and recovery.
• Limited access to conventional sleep studies due to inconvenience hinders timely diagnosis.
• Smartphones offer a portable and accessible solution for sleep monitoring via built-in sensors.

Purpose of the Study:

• To detect and evaluate sleep apnea in post-stroke patients using a smartphone-based system.
• To extract multimodal digital biomarkers for characterizing sleep patterns in stroke survivors.
• To assess the feasibility of using smartphones for sleep apnea screening in this population.

Main Methods:

• Overnight sleep tests were conducted on 30 subacute stroke patients and 30 controls.
• A smartphone-based system recorded audio, accelerometer, and oximetry data.
• Custom algorithms analyzed signals to compute respiratory, oxygenation, and sleep position indices.

Main Results:

• Stroke patients exhibited a significantly higher apnea-hypopnea index (AHI) than controls (28 vs 14, p=0.006).
• 67% of stroke patients had moderate-to-severe sleep apnea (AHI ≥ 15), compared to 40% of controls.
• Stroke patients spent more time mouth breathing and sleeping in the supine position, factors contributing to airway obstruction.

Conclusions:

• Smartphone-based monitoring effectively identifies sleep apnea in post-stroke patients.
• Novel multimodal digital biomarkers enhance understanding of post-stroke sleep apnea.
• This approach facilitates early detection, potentially reducing the burden of sleep apnea and improving stroke rehabilitation outcomes.