A novel intermittent negative air pressure device ameliorates obstructive sleep apnea syndrome in adults.

PURPOSE: Patients with obstructive sleep apnea syndrome (OSAS) have difficulties in compliance with continuous positive airway pressure (CPAP) and the treatment outcome is heterogeneous. We proposed a proof-of-concept study of a novel intermittent negative air pressure (iNAP®) device for physicians to apply on patients who have failed or refused to use CPAP. METHODS: The iNAP® device retains the tongue and the soft palate in a forward position to decrease airway obstruction. A full nightly usage with the device was evaluated with polysomnography. Subgrouping by baseline apnea-hypopnea index (AHI) and body mass index (BMI) with different treatment response criteria was applied to characterize the responder group of this novel device. RESULTS: Thirty-five patients were enrolled: age 41.9 ± 12.2 years (mean ± standard deviation), BMI 26.6 ± 4.3 kg/m2, AHI 41.4 ± 24.3 events/h, and oxygen desaturation index (ODI) 40.9 ± 24.4 events/h at baseline. AHI and ODI were significantly decreased (p < 0.001) by the device. Patients with moderate OSAS, with baseline AHI between 15 to 30 events/h, achieved 64% response rate; and non-obese patients, with BMI below 25 kg/m2, achieved 57% response rate, with response rate defined as 50% reduction in AHI from baseline and treated AHI lower than 20. There were minimal side effects reported. CONCLUSIONS: In a proof-of-concept study, the device attained response to treatment as defined, in more than half of the moderate and non-obese OSAS patients, with minimal side effects.

Building a model to precisely target the responders of a novel intermittent negative air pressure device-with mechanism definition.

OBJECTIVE: Due to the complexity of obstructive sleep apnea syndrome (OSAS), engaging patients in the right treatment poses a constant challenge. A novel oral pressure therapy device, the intermittent negative air pressure Sleep Therapy System (iNAP), has proven to ameliorate respiratory events for OSAS patients. However, the mode of action and the characteristics of its responders are not yet fully understood. Therefore, we have first disclosed the mechanism and provided systemic models to predict the treatment response. METHODS: Series of imaging studies were carried out to differentiate the anatomical features of iNAP responders versus non-responders. Compatible electroencephalography was used to evaluate sleep status during magnetic resonance imaging (MRI) assessments. RESULTS: The upper airway volume was statistically widened under the iNAP treatment while patients were naturally asleep (p < 0.05). Negative predictors included several parameters related to oral-tissue redundancy, enlarged middle pharyngeal space, and longer distance of hyoidale to mandibular plane. Positive predictors included larger angulation of sella-articulate-gonion, longer distance of anterior nasal spine to posterior nasal spine, and elongated tongue, which could correspond to the fact that the iNAP had a greater ability to widen the retropalatal region. Furthermore, algorithms developed by these predictors were built to predict treatment response. CONCLUSIONS: We were able to confirm the effect of the iNAP in widening the upper airway. Anatomic features that can be visually observed or obtained through X-ray films, accompanied with the resulting algorithms, were provided to facilitate physicians' ability to predict patients' treatment response to the iNAP with greater sensitivity and efficiency.