Obstructive Sleep Apnea (OSA) is a common disorder where breathing repeatedly stops and starts during sleep due to a blocked or narrowed upper airway. This condition often goes undiagnosed, leading many people to seek convenient and affordable screening options. The high cost and inconvenience of traditional in-lab sleep studies have driven consumer interest toward using smartphone technology for an initial assessment. People are hoping that a simple application can provide insight into their nightly breathing patterns and whether they should consult a physician.
The Current Landscape of Sleep Apnea Apps
No single app can provide a medical diagnosis of sleep apnea, but many applications are available that function as screening or monitoring tools. These fall into two main categories: general sleep-tracking apps and more specialized, often subscription-based, screening tools. General apps often use the smartphone’s microphone to record and analyze snoring, which may give some indication of disrupted breathing. Specialized tools are designed specifically to look for patterns associated with an elevated risk of OSA, positioning themselves as preliminary screeners.
A few sophisticated screening apps have received regulatory clearance from bodies like the U.S. Food and Drug Administration (FDA) to be used as prescription-only software to pre-screen for moderate to severe OSA. These tools analyze breathing and snoring sounds recorded on a smartphone over multiple nights. Integrating a smartphone app with external sensors, such as those found in smartwatches, can also provide additional data, like heart rate variability, to enhance the screening process.
How Smartphone Technology Attempts Screening
The primary mechanism most smartphone apps use to screen for sleep apnea is sophisticated acoustic analysis. These applications leverage the phone’s microphone, which is placed on a bedside table, to record sounds throughout the night. Advanced digital signal processing and artificial intelligence algorithms then analyze the audio data to identify specific sound signatures.
The algorithms are trained to differentiate simple snoring from more concerning sounds, such as gasping, choking, or distinct pauses in breathing. By analyzing the frequency and duration of these events, the app can estimate an Apnea-Hypopnea Index (AHI) number, which is an average of significant breathing interruptions per hour of sleep.
Movement Tracking
Another method is tracking movement and body position, often using the phone’s internal accelerometer. Restlessness and frequent changes in sleeping position can correlate with sleep disturbance, which is a symptom of poor sleep quality, potentially caused by OSA. While acoustic analysis is more directly related to breathing events, movement tracking provides a secondary layer of data to help paint a picture of the user’s overall sleep quality. However, these methods only estimate events and do not measure the physiological changes required for a definitive diagnosis.
Why Apps Cannot Provide a Medical Diagnosis
The data gathered by a smartphone app is suitable for screening but is insufficient for a medical diagnosis because it cannot measure the physiological parameters required by sleep specialists. A formal diagnosis of Obstructive Sleep Apnea relies on a Polysomnography (PSG) study or a validated Home Sleep Apnea Test (HSAT). These tests measure blood oxygen saturation (SpO2) and, in the case of in-lab PSG, brain activity (EEG) to determine true sleep time and the severity of oxygen drops.
A standard smartphone cannot reliably and accurately measure the drops in blood oxygen saturation that define the severity of apnea events. Additionally, a full PSG tracks brain waves, eye movements, and muscle activity, providing a detailed breakdown of sleep stages, which is not possible with the phone’s built-in sensors alone.
If a screening app suggests a high risk of OSA, the next step is to consult a healthcare professional. A physician will then use the app’s data in conjunction with a medical history to determine if a formal sleep study is warranted. A definitive diagnosis is necessary to accurately determine the type and severity of the sleep disorder, which guides the appropriate medical treatment plan.