Home sleep monitor for detecting apnea episodes by nasal flow and tracheal sound recordings.

Hida, Wataru; Miki, Hiroshi; Kikuchi, Yoshihiro; Miura, Chieko; Iwase, Nobuhisa; Shimizu, Yoshio; Takishima, Tamotsu

doi:10.1620/tjem.156.suppl_137

Cited by 16 publications

(8 citation statements)

References 5 publications

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“…Sef represents T-section at the constriction with its associated sound pressure source p . The value of p is 20% of the pressure calculated by (3). Similarly, p is 40% of the calculated pressure, and p is 20%, etc.…”

Section: B Acoustic Source Modelingmentioning

confidence: 91%

Modeling and measurement of flow effects on tracheal sounds

Harper

Pasterkamp

Kiyokawa

et al. 2003

IEEE Trans. Biomed. Eng.

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The analysis of breathing sounds measured over the extrathoracic trachea offers a noninvasive technique to monitor obstructions of the respiratory tract. Essential to development of this technique is a quantitative understanding of how such tracheal sounds are related to the underlying tract anatomy, airflow, and disease-induced obstructions. In this study, the first dynamic acoustic model of the respiratory tract was developed that takes into consideration such factors as turbulent sound sources and varying glottal aperture. Model predictions were compared to tracheal sounds measured on four healthy subjects at target flow rates of 0.5, 1.0, 1.5, and 2.0 L/s, and also during nontargeted breathing. Both the simulation and measurement spectra depicted increasing sound power with increasing flow, with smaller incremental increases at the higher flow rates. A sound power increase of approximately 30 dB between a flow rate of 0.5 and 2.0 L/s was observed in both the simulated and measured spectra. Variations of as much as 15 dB over the 300-600 Hz frequency band were noted in the sound power produced during targeted and nontargeted breathing maneuvers at the same flow rates. We propose that this variability was in part due to changes in glottal aperture area, which is known to vary during normal respiration and has been observed as a method of flow control. Model simulations incorporating a turbulent source at the glottis with respiratory cycle variations in glottal aperture from 0.64 cm2 to 1.4 cm2 explained approximately 10 dB of the measured variation. This study provides the first links between spatially distributed sound sources due to turbulent flow in the respiratory tract and noninvasive tracheal sounds measurements.

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Section: B Acoustic Source Modelingmentioning

confidence: 91%

Modeling and measurement of flow effects on tracheal sounds

Harper

Pasterkamp

Kiyokawa

et al. 2003

IEEE Trans. Biomed. Eng.

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“…The feasibility of monitoring breath sounds over the trachea to detect apneic events was perhaps first described by Krumpe and Cummiskey 11 and Cummiskey et al 12 Subsequently, Hida et al 13 reported their uncontrolled case series using tracheal sound recordings combined with airflow measures at the nose. Other studies 14,15 included investigations comparing tracheal sound records to airflow detection plus continuous pulse oximetry.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of the Accuracy of SNAP Technology Sleep Sonography in Detecting Obstructive Sleep Apnea in Adults Compared to Standard Polysomnography

Liesching

Carlisle

Marte

et al. 2004

Chest

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“…The portable home sleep monitoring system we have renovated is easier to operate and to analyse, and has more cost-saving benefits than the previous system [2], We can obtain detailed information on sleep apnea within 10 min and analysis by a host computer on the following day. However, there still remain several problems.…”

Section: Discussionmentioning

confidence: 99%

“…is burdensome, laborious, time consuming, costly and inconvenient as a screening test or epidemiological study, particularly outside of a hospital. We previously reported a portable sleep monitoring system with a casette data rec order [2], which records analog signals of nasal flow, tra cheal sound and electrocardiogram (ECG). Since this sys tem requires a play back of the casette tape by high-speed performance for analysis, it is not yet feasible for clinical purposes.…”

Section: Introductionmentioning

confidence: 99%

Prevalence of Sleep Apnea among Japanese Industrial Workers Determined by a Portable Sleep Monitoring System

et al. 1993

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We developed a new portable sleep monitoring system and studied the prevalence of sleep apnea syndrome among Japanese industrial workers. This device assessed three kinds of parameters: nasal airflow, tracheal sound and electrocardiogram (ECG), and digitally stored the clock time of the onset of apnea, apnea duration and R-R intervals by a built-in microcomputer. After monitoring, the portable sleep monitor was connected to a host computer, and apneic episodes, the so-called ‘apnea index’ as apneic episodes corrected by measuring time (‘AI’) and R-R intervals were analyzed. In 170 inpatients referred to our sleep clinic, sleep monitoring by this device was performed simultaneously with all-night polysomnography, and the sensitivity and specificity of this device was determined under different criteria of the apnea index (AI) (AI > 5,10, 15 and 20 episodes/h) by polysomnography. In all AI criteria, the sensitivity was more than 90%, and the specificity was also reasonably high. Using this system, successive 2-night home sleep monitoring was performed on 168 healthy workers in one Japanese industrial company, and 159 people (140 males; 19 females) who had successful monitoring were analyzed. The percentage of persons who had ‘AΓ of more than 10 episodes/h was 7.5%. There were no significant correlations between ‘AI’ and age, body weight or scores estimated by sleep questionnaires. These results suggest that even in people who are seemingly healthy significant apneic episodes could be detected by the portable home sleep monitoring system. This system may therefore be useful in evaluating the occurrence of sleep apnea syndrom in general populations.

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Home sleep monitor for detecting apnea episodes by nasal flow and tracheal sound recordings.

Cited by 16 publications

References 5 publications

Modeling and measurement of flow effects on tracheal sounds

Modeling and measurement of flow effects on tracheal sounds

Evaluation of the Accuracy of SNAP Technology Sleep Sonography in Detecting Obstructive Sleep Apnea in Adults Compared to Standard Polysomnography

Prevalence of Sleep Apnea among Japanese Industrial Workers Determined by a Portable Sleep Monitoring System

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