Apnea and heart rate detection from tracheal body sounds for the diagnosis of sleep-related breathing disorders

Abstract

Sleep apnea is one of the most common sleep disorders. Here, patients suffer from multiple breathing pauses longer than 10 s during the night which are referred to as apneas. The standard method for the diagnosis of sleep apnea is the attended cardiorespiratory polysomnography (PSG). However, this method is expensive and the extensive recording equipment can have a significant impact on sleep quality falsifying the results. To overcome these problems, a comfortable and novel system for sleep monitoring based on the recording of tracheal sounds and movement data is developed. For apnea detection, a unique signal processing method utilizing both signals is introduced. Additionally, an algorithm for extracting the heart rate from body sounds is developed. For validation, ten subjects underwent a full-night PSG testing, using the developed sleep monitor in concurrence. Considering polysomnography as gold standard the developed instrumentation reached a sensitivity of 92.8% and a specificity of 99.7% for apnea detection. Heart rate measured with the proposed method was strongly correlated with heart rate derived from conventional ECG (r = 0.8164). No significant signal losses are reported during the study. In conclusion, we demonstrate a novel approach to reliably and noninvasively detect both apneas and heart rate during sleep.

Breathing detection from tracheal sounds in both temporal and frequency domains in the context of phrenic nerve stimulation

“…But their study detects also heartbeats and movements which gives a more complete monitoring. A more recent study of the same group [9] advance in result with a sensitivity of 92.8% and a specificity of 99.7%. But this algorithm, based on temporal domain with 3 envelopes, needs to scan the entire recording, so it cannot be applied in real-time, and is not adapted to phrenic stimulation system monitoring.…”

Automated sleep stage classification based on tracheal body sound and actigraphy

“…It can therefore be assumed that the new sleep monitor can be used for simple sleep monitoring and preliminary screening at home. Additionally, previous research proved that the new sleep monitor is also able to diagnose one of the most common sleep disorders OSA [ 19 ], [ 20 ]. Using sleep staging, it is suggested that the monitor can now also be used to diagnose other sleep disorders, such as insomnia, or for a preliminary screening to decide whether a PSG is necessary or not.…”

“…This curve can now easily be used to detect breathing cycles and estimate airflow. A broader discussion of the challenges of relating the amount of airflow to tracheal breathing sounds can be found in [ 20 ], [ 31 ], [ 32 ]. With this information, the respiratory features presented in Table 2 (Tab.…”

“…A novel type-4 monitoring system has previously been developed by Kalkbrenner et al [ 17 ], [ 18 ]. This monitor utilizes tracheal body sound and actigraphy to screen for OSA [ 19 ], [ 20 ]. This allows simple setup and high comfort, minimizing the effect on sleep quality while outperforming similar existing ambulatory diagnostic.…”

Vision-Based Heart and Respiratory Rate Monitoring During Sleep – A Validation Study for the Population at Risk of Sleep Apnea

“…Moreover, an attachment of multiple sensors could potentially be inconvenient during sleep. Various contactless technologies were explored for overnight respiratory rate and/or heart rate monitoring including applications of radar [24], WiFi [25], audio recording [26], [27], pressure sensors [28], depth cameras [29], thermal cameras [30], and infrared cameras [31].…”