Research Article| Volume 9, ISSUE 1, P100-107, February 2023

Download started.


Keep it simple: A novel technique for measuring airflow using a wireless patch

Published:December 03, 2022DOI:



      Despite the growing use of home sleep testing for obstructive sleep apnea (OSA), there are significant barriers that make it difficult for patients. This study aimed to evaluate a new set of wireless patches for the detection of OSA as compared to polysomnography (PSG) respiratory signals. Safety was also evaluated.


      Patients (n = 25; mean age = 51.3; SD = 15.6) undergoing standard PSG evaluation for OSA wore 2 device patches applied on the chest and abdomen to provide surrogates of respiratory effort and derived airflow. Two sets of respiratory data (with common SpO2 and heart rate as a reference from PSG) were created, one from PSG and one from the device patches. Data were scored by a Registered Polysomnographic Technologist. Linear regression analyses and Bland-Altman plots were used to compare the two derived apnea-hypopnea indices (AHI). Bench testing was performed to determine whether the device patch respiratory signal accuracy remained consistent for different body characteristics.


      There was a significant correlation for AHI between the device patch and PSG (r = 0.979; P < .001; 95% CI 0.952, 1.00). There were also significant correlations between PSG and the device patch for supine AHI (r = 0.866, P < .001, 95% CI 0.610, 0.965) and nonsupine AHI (r = 0.983; <0.001, 95% CI 0.954, 1.00). No differences in respiratory signal accuracy were found with bench testing comparison groups.


      These preliminary results suggest that the device patch may be an effective way to measure respiratory dynamics, including derived airflow, to evaluate OSA. Results show promise as a new innovative method for home sleep testing.



      AASM (American Academy of Sleep Medicine), AE (Adverse Events), AHI (Apnea-Hypopnea Index), BLE (Low-energy Bluetooth), BMI (Body Mass Index), CMS (Centers for Medicare and Medicaid), CPAP (Continuous Positive Airway Pressure), ECG (Electrocardiogram), EDF (European Data Format), EEG (Electroencephalogram), EMG (Electromyogram), EOG (Electrooculogram), HSAT (Home Sleep Apnea Testing), OSA (Obstructive Sleep Apnea), POSA (Positional Obstructive Sleep Apnea), PSG (Nocturnal Polysomnography), RDI (Respiratory disturbance index), RIP (Respiratory inductance plethysmography), SpO2 (Oxygen Saturation), WLP (Wesper Lab Patches), TST (Total Sleep Time)
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Sleep Health: Journal of the National Sleep Foundation
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Benjafield AV
        • Ayas NT
        • Eastwood PR
        • et al.
        Estimation of the global prevalence and burden of obstructive sleep apnoea: a literature-based analysis.
        Lancet Respir Med. 2019; 7: 687-698
      1. Kapur VK. Obstructive sleep apnea: diagnosis, epidemiology, and economics. Respir Care 2010;55(9):1155-67. (,

        • Peppard PE
        • Young T
        • Barnet JH
        • Palta M
        • Hagen EW
        • Hla KM.
        Increased prevalence of sleep-disordered breathing in adults.
        Am J Epidemiol. 2013; 177: 1006-1014
        • Levy P
        • Kohler M
        • McNicholas WT
        • et al.
        Obstructive sleep apnoea syndrome.
        Nat Rev Dis Primers. 2015; 1: 15015
        • Ayappa I
        • Rapaport BS
        • Norman RG
        • Rapoport DM.
        Immediate consequences of respiratory events in sleep disordered breathing.
        Sleep Med. 2005; 6: 123-130
        • Budhiraja R
        • Quan SF.
        Sleep-disordered breathing and cardiovascular health.
        Curr Opin Pulm Med. 2005; 11: 501-506
        • Javaheri S
        • Barbe F
        • Campos-Rodriguez F
        • et al.
        Sleep apnea: types, mechanisms, and clinical cardiovascular consequences.
        J Am Coll Cardiol. 2017; 69: 841-858
        • Peppard PE
        • Young T
        • Palta M
        • Skatrud J.
        Prospective study of the association between sleep-disordered breathing and hypertension.
        N Engl J Med. 2000; 342: 1378-1384
        • Cohen-Zion M
        • Stepnowsky C
        • Marler Shochat T
        • Kripke DF
        Ancoli-Israel S. Changes in cognitive function associated with sleep disordered breathing in older people.
        J Am Geriatr Soc. 2001; 49: 1622-1627
        • Lam JC
        • Mak JC
        • Ip MS.
        Obesity, obstructive sleep apnoea and metabolic syndrome.
        Respirology. 2012; 17: 223-236
        • Johnson KG
        • Johnson DC.
        Frequency of sleep apnea in stroke and TIA patients: a meta-analysis.
        J Clin Sleep Med. 2010; 6: 131-137
        • Ancoli-Israel S
        • Gehrman P
        • Kripke DF
        • et al.
        Long-term follow-up of sleep disordered breathing in older adults.
        Sleep Med. 2001; 2: 511-516
        • Ancoli-Israel S
        • Kripke DF
        • Klauber MR
        • Mason WJ
        • Fell R
        • Kaplan O.
        Sleep-disordered breathing in community-dwelling elderly.
        Sleep. 1991; 14: 486-495
        • Mehra R
        • Stone KL
        • Blackwell T
        • et al.
        Prevalence and correlates of sleep-disordered breathing in older men: osteoporotic fractures in men sleep study.
        J Am Geriatr Soc. 2007; 55: 1356-1364
        • Kim RD
        • Kapur VK
        • Redline-Bruch J
        • et al.
        An economic evaluation of home versus laboratory-based diagnosis of obstructive sleep apnea.
        Sleep. 2015; 38: 1027-1037
      2. Berry RB, Quan SF, Abreu AR, Bibbs ML, DelRosso L, Harding SM. The AASM manual for the scoring of sleep and associated events: rules, terminology and technical specifications, version 2.6 Darien, Illinios: American Academy of Sleep Medicine.

      3. Collop NA, Anderson WM, Boehlecke B, et al. Clinical guidelines for the use of unattended portable monitors in the diagnosis of obstructive sleep apnea in adult patients. Portable Monitoring Task Force of the American Academy of Sleep Medicine. J Clin Sleep Med 2007;3(7):737-47. (,,

        • Collop NA
        • Tracy SL
        • Kapur V
        • et al.
        Obstructive sleep apnea devices for out-of-center (OOC) testing: technology evaluation.
        J Clin Sleep Med. 2011; 7: 531-548
        • Kapur VK
        • Auckley DH
        • Chowdhuri S
        • et al.
        Clinical practice guideline for diagnostic testing for adult obstructive sleep apnea: an American Academy of Sleep Medicine Clinical Practice Guideline.
        J Clin Sleep Med. 2017; 13: 479-504
        • Miller JN
        • Schulz P
        • Pozehl B
        • Fiedler D
        • Fial A
        • Berger AM.
        Methodological strategies in using home sleep apnea testing in research and practice.
        Sleep Breath. 2018; 22: 569-577
      4. International Organization for Standardization. 2018. Biological evaluation of medical devices - Part 1: Evaluation and testing within a risk management process. (ISO 10993-1). Retrieved from

        • Berry RB
        • Brooks R
        • Gamaldo C
        • et al.
        AASM Scoring Manual Updates for 2017 (Version 2.4).
        J Clin Sleep Med. 2017; 13: 665-666
        • Berry RB
        • Quan SF
        • Abreu AR
        • et al.
        The AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications.
        American Academy of Sleep Medicine, Darien, IL2020
        • Bland JM
        • Altman DG.
        Statistical methods for assessing agreement between two methods of clinical measurement.
        Lancet. 1986; 1 (Statistical methods for assessing agreement between two methods of clinical measurement.): 307-310
        • Yalamanchali S
        • Farajian V
        • Hamilton C
        • Pott TR
        • Samuelson CG
        • Friedman M.
        Diagnosis of obstructive sleep apnea by peripheral arterial tonometry: meta-analysis.
        JAMA Otolaryngol Head Neck Surg. 2013; 139: 1343-1350
        • Kaplan V
        • Zhang JN
        • Russi EW
        • Bloch KE.
        Detection of inspiratory flow limitation during sleep by computer assisted respiratory inductive plethysmography.
        Eur Respir J. 2000; 15: 570-578
        • Konno K
        • Mead J.
        Measurement of the separate volume changes of rib cage and abdomen during breathing.
        J Appl Physiol. 1967; 22: 407-422
        • Mason DG
        • Iyer K
        • Terrill PI
        • Wilson SJ
        • Suresh S.
        Pediatric obstructive sleep apnea assessment using pulse oximetry and dual RIP bands.
        in: Conference proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society IEEE Engineering in Medicine and Biology Society Conference. 2010. 2010: 6154-6157
        • Cartwright RD.
        Effect of sleep position on sleep apnea severity.
        Sleep. 1984; 7: 110-114
        • George CF
        • Millar TW
        • Kryger MH.
        Sleep apnea and body position during sleep.
        Sleep. 1988; 11: 90-99
        • Oksenberg A
        • Silverberg DS
        • Arons E
        • Radwan H.
        Positional vs nonpositional obstructive sleep apnea patients: anthropomorphic, nocturnal polysomnographic, and multiple sleep latency test data.
        Chest. 1997; 112: 629-639
        • Ravesloot MJ
        • Frank MH
        • van Maanen JP
        • Verhagen EA
        • de Lange J
        • de Vries N.
        Positional OSA part 2: retrospective cohort analysis with a new classification system (APOC).
        Sleep Breath. 2016; 20: 881-888
        • Ioachimescu OC
        • Dholakia SA
        • Venkateshiah SB
        • et al.
        Improving the performance of peripheral arterial tonometry-based testing for the diagnosis of obstructive sleep apnea.
        J Investig Med. 2020; 68: 1370-1378
        • Massie F
        • Mendes de Almeida D
        • Dreesen P
        • Thijs I
        • Vranken J
        • Klerkx S.
        An evaluation of the NightOwl home sleep apnea testing system.
        J Clin Sleep Med. 2018; 14: 1791-1796
        • Shochat T
        • Hadas N
        • Kerkhofs M
        • et al.
        The SleepStrip: an apnoea screener for the early detection of sleep apnoea syndrome.
        Eur Respir J. 2002; 19: 121-126