Sleep Apnea Detection Using Smart Hearables

Accurate, photoplethysmography (PPG)-based vital signs measurements can be done using smart hearables. Our approach uses proprietary algorithms and multiple photodiode/sensor pairs to effectively remove motion artifacts. As such, accurate bio-signals can be obtained dynamically under motion, and in a continuous real-time manner.

By removing the motion noise instead of using accelerometer-based compensation techniques, we can preserve very detailed raw information that can in turn be used to compute other bio-signals including, respiratory rate (RR), heart rate variability (HRV), and R-R interval (RRI).

With these parameters, sleep apnea detection can be done using our smart hearables, in a non-invasive, continuous real-time manner. Upon detecting sleep apnea episodes in users, the smart hearable can issue an audible instruction to wake them up, thus allowing the user to readjust their sleep posture. This can potentially be a useful home-based sleep apnea monitoring tool.

The miniature sensing module comprises multiple light source and sensor pairs, and a dedicated microcontroller. Proprietary, advanced digital signal processing and algorithms are used to remove motion noise and calculate the various vital signs. These physiological data can be sent directly to a smart phone via Bluetooth Low Energy (BLE), hence third party apps can be supported. The miniature sensing module can easily be integrated into third party smart hearables, and has already been integrated into many commercially available hearables that measure heart rate.

This technology offer can be used to detect sleep apnea episodes:

• This technology is highly suitable as a home-based monitoring device as the sleep apnea episodes can be determined by HR, RR, HRV, RRI (and SpO2 in 2nd half of 2021).
• The sensing module is small, allowing for small earbuds which fit comfortably during sleep.
• The smart earbuds can immediately alert and wake the user during an apnea episode
• Stronger and more accurate signals can be obtained compared to wrist wearables due to less movements of the earbuds, as they are inherently constrained in the ear in a consistent position.
• Popular usage: an increasing number of youth and middle-aged adults prefer earbuds, and even wear earbuds to sleep

In Asia, the prevalence of symptomatic obstructive sleep apnea (OSA) is 4.1-7.5% in middle-aged men, and 2.1-3.2% in women (2007) (https://pubmed.ncbi.nlm.nih.gov/17217123/), with increasing prevalence; many more go undiagnosed. In Singapore, 3 in 10 middle-aged men are diagnosed with OSA (2015). There is an increasing trend in patients wanting home-based solutions to take charge of their own health. This trend is also catalysed by reduced clinic visits and screening due to Covid-19.

• Small and lightweight earbuds are comfortable for sleep
• Convenient, home-based monitoring
• Continuous real time sensing combined with vocal cues allows the device to wake the user up when breathing stops
• Easy integration with 3rd party apps allows the user to own and have access to their own physiological data which they can monitor over time