title: Tidal breathing parameters measured using structured light plethysmography in healthy children and those with asthma before and after bronchodilator.
abstract: Structured light plethysmography (SLP) is a light-based, noncontact technique that measures tidal breathing by monitoring displacements of the thoracoabdominal (TA) wall. We used SLP to measure tidal breathing parameters and their within-subject variability (v) in 30 children aged 7-16 years with asthma and abnormal spirometry (forced expiratory volume in 1 sec [FEV1] <80% predicted) during a routine clinic appointment. As part of standard care, the reversibility of airway obstruction was assessed by repeating spirometry after administration of an inhaled bronchodilator. In this study, SLP was performed before and after bronchodilator administration, and also once in 41 age-matched controls. In the asthma group, there was a significant increase in spirometry-assessed mean FEV1 after administration of bronchodilator. Of all measured tidal breathing parameters, the most informative was the inspiratory to expiratory TA displacement ratio (IE50SLP, calculated as TIF50SLP/TEF50SLP, where TIF50SLPis tidal inspiratory TA displacement rate at 50% of inspiratory displacement and TEF50SLPis tidal expiratory TA displacement rate at 50% of expiratory displacement). Median (m) IE50SLPand its variability (vIE50SLP) were both higher in children with asthma (prebronchodilator) compared with healthy children (mIE50SLP: 1.53 vs. 1.22,P<0.001; vIE50SLP: 0.63 vs. 0.47,P<0.001). After administration of bronchodilators to the asthma group, mIE50SLPdecreased from 1.53 to 1.45 (P=0.01) and vIE50SLPdecreased from 0.63 to 0.60 (P=0.04). SLP-measured tidal breathing parameters could differentiate between children with and without asthma and indicate a response to bronchodilator.
authors.affiliation: Institute for Science and Technology in Medicine, Keele University, Stoke-on-Trent, United Kingdom.
authors.forename: Hamzah
authors.initials: H
authors.lastname: Hmeidi
authors.affiliation: PneumaCare, Ltd., Cambridgeshire, United Kingdom.
authors.forename: Shayan
authors.initials: S
authors.lastname: Motamedi-Fakhr
authors.affiliation: Institute for Science and Technology in Medicine, Keele University, Stoke-on-Trent, United Kingdom.
authors.forename: Edward
authors.identifier: http://orcid.org/0000-0003-0877-5110
authors.initials: E
authors.lastname: Chadwick
authors.affiliation: Institute for Science and Technology in Medicine, Keele University, Stoke-on-Trent, United Kingdom.|University Hospitals of North Midlands, Stoke-on-Trent, United Kingdom.
authors.forename: Francis J
authors.initials: FJ
authors.lastname: Gilchrist
authors.affiliation: Institute for Science and Technology in Medicine, Keele University, Stoke-on-Trent, United Kingdom.|University Hospitals of North Midlands, Stoke-on-Trent, United Kingdom.
authors.forename: Warren
authors.initials: W
authors.lastname: Lenney
authors.affiliation: PneumaCare, Ltd., Cambridgeshire, United Kingdom.|Addenbrookes Hospital, Cambridge, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Iles
authors.affiliation: PneumaCare, Ltd., Cambridgeshire, United Kingdom.
authors.forename: Rachel C
authors.initials: RC
authors.lastname: Wilson
authors.affiliation: University Hospitals of North Midlands, Stoke-on-Trent, United Kingdom john.alexander@uhns.nhs.uk.
authors.forename: John
authors.initials: J
authors.lastname: Alexander
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000188:drug therapy / Q000503:physiopathology*; D001993:Bronchodilator Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D010991:Plethysmography; D012119:Respiration / Q000187:drug effects*; D013147:Spirometry; D013990:Tidal Volume / Q000187:drug effects
chemical_list: D001993:Bronchodilator Agents
keywords: Asthma; IE50SLP; bronchodilator; children; structured light plethysmography; tidal breathing