Results of a definitive clinical trial show that a new, disposable diagnostic patch effectively detects obstructive sleep apnoea across all severity levels.
Results show that the total rate of clinical agreement between the patch and standard in-lab polysomnography was 87.4% with 95% confidence interval of 81.4% to 91.9%.
According to the authors, the study results will be used in obtaining approval from the US Food and Drug Administration for the device, SomnaPatch. The skin-adhesive diagnostic patch weighs less than one ounce and records nasal pressure, blood oxygen saturation, pulse rate, respiratory effort, sleep time and body position.
"Our study provided clinical validation of a new wearable device for diagnosing sleep apnoea," said principal investigator Dr Maria Merchant, CEO of Somnarus Inc. "It was most surprising to us how well this inexpensive miniature device performed in comparison with in-lab sleep studies."
Simultaneous poly-somnography and patch recordings from 174 subjects were included in the analysis. An additional home usability study found that 38 out of 39 users were successful in activating the diagnostic patch and collecting at least 4 hours of sleep data while relying only on the instructions included with the device.
"Most home sleep diagnostic devices are difficult for patients to use and are disruptive to patient's sleep," said Merchant. "Our study showed that this wearable home sleep monitor is very comfortable, easy to use and does not negatively affect sleep."
Introduction: Portable home sleep monitors are being increasingly utilized in clinical practice for diagnosing sleep apnea. However, most type III home monitors are difficult for patients to set up and wearing the monitors is disruptive to patient’s typical sleep pattern. The diagnostic value of an inexpensive easy-to-use light-weight flexible skin-adhesive patch (SomnaPatch) that minimally affects sleep was evaluated in this study.
Methods: Simultaneous poly-somnography (PSG) and the diagnostic patch recordings were made in 179 subjects (mean age 54.0 ± 13.6 y, 55% male) selected from the databases of patients previously tested with PSG to ensure even representation of the clinically important apnea-hypopnea index (AHI) ranges. The skin-adhesive diagnostic patch weighs less than one ounce and records nasal pressure, blood oxygen saturation, pulse rate, respiratory effort, sleep time and body position (S3C4O2P2E3R2 category). To compare the apnea-hypopnea index of the diagnostic patch with poly-somnography, all recordings were auto-scored with the Somnolyzer software (Respironics). Bland-Altman analysis was performed. Sensitivity, specificity and accuracy were calculated and receiver operating characteristic (ROC) curves were constructed for six AHI thresholds (5, 10, 15, 20, 25 and 30 events per hour). The rate of clinical agreement and positive likelihood ratio were calculated.
Results: Overnight recordings from 174 subjects were included in the final analysis. All six ROC curves had area under the curve of over 0.9. Sensitivity, specificity and accuracy for the optimal threshold of AHI≥15 were 0.86, 0.83 and 0.85 respectively. Positive likelihood ratio (LR+) was 7.4. Bland-Altman analysis showed that the bias was 0.9 events per hour and the limits of agreement were 18.1 and -16.1. The rate of clinical agreement between recordings with PSG AHI≥30 and patch AHI≥30 and was 85%. The rate of clinical agreement between recordings with PSG AHI Conclusion: The new diagnostic patch offers excellent clinical value for detecting sleep apnea across all severity levels as compared with standard in-lab poly-somnography.
M Merchant, M Farid-Moayer, Y Zobnin, A Parfenov, J Askeland, A Sturm