TY - JOUR T1 - Small-scale clinical validation of structured light plethysmography (SLP) preliminary reference equations JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2020.3367 VL - 56 IS - suppl 64 SP - 3367 AU - Shayan Motamedi Fakhr AU - Nicki Barker AU - John Alexander AU - Richard Iles AU - Brendan G Cooper Y1 - 2020/09/07 UR - http://erj.ersjournals.com/content/56/suppl_64/3367.abstract N2 - Background: SLP is a non-contact measurement technique for tidal breathing patterns. However, in order to be used clinically it requires reference values. We have developed a set of growth adjusted reference equations for 7 SLP parameters. We aim to investigate the clinical validity of those equations.Method and Data: Our new reference equations were applied to a set of independent adult data with 10 normal subjects [Mean (SD); 40.2 (12.7) years, 169.9 (9.2) cm, 5 Male] and 24 patients [56.0 (18.0) years, 172.0 (10.0) cm, 16 Male] . Patients had a range of respiratory disorders (COPD, asthma, emphysema, sarcoidosis) with varying severities. Respiratory rate (RR), inspiratory time (Ti), expiratory time (Te), duty cycle (Ti/Ttot), phase (thoraco-abdominal asynchrony [TAA]), relative thoracic contribution and IE50 (surrogate measure of airway obstruction), their predicted values and z-scores were calculated for each subject. Breathing pattern was defined as abnormal if any of the 7 z-scores was statistically abnormal (z>1.96 or z<-1.96).Results: Using the abnormality criterion above, 27/34 subjects were correctly identified (accuracy=79.4%, sensitivity=17/24=70.8% and specificity=10/10=100%). Correct identifications were not limited to severe and very severe conditions. In fact, 10 out of 17 correct patient classifications had a mild or moderate condition (GOLD, GINA). Phase, IE50 and Ti/Ttot showed the most discriminatory power.Conclusion: The results of this small-scale validation show that statistical abnormality translates to clinical abnormality with reasonable accuracy. High specificity and accuracy suggest the potential of SLP as a screening tool, and further work continues.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 3367.This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only). ER -