Monitoring.

<p>A) Optoelectronic plethysmography (OEP): retro-reflective markers separating both the upper rib cage (RCp) and abdomen (AB) compartments. B) Respiratory Inductive plethysmography (RIP): elastic bands positioned on RCp and AB compartments. C) RCp and AB movement during respiratory cicles.</p

Thoracoabdominal asynchrony: Two methods in healthy, COPD, and interstitial lung disease patients

<div><p>Background</p><p>Thoracoabdominal asynchrony is the nonparallel motion of the ribcage and abdomen. It is estimated by using respiratory inductive plethysmography and, recently, using optoelectronic plethysmography; however the agreement of measurements between these 2 techniques is unknown. Therefore, the present study compared respiratory inductive plethysmography with optoelectronic plethysmography for measuring thoracoabdominal asynchrony to see if the measurements were similar or different.</p><p>Methods</p><p>27 individuals (9 healthy subjects, 9 patients with interstitial lung disease, and 9 with chronic obstructive pulmonary disease performed 2 cycle ergometer tests with respiratory inductive plethysmography or optoelectronic plethysmography in a random order. Thoracoabdominal asynchrony was evaluated at rest, and at 50% and 75% of maximal workload between the superior ribcage and abdomen using a phase angle.</p><p>Results</p><p>Thoracoabdominal asynchrony values were very similar in both approaches not only at rest but also with exercise, with no statistical difference. There was a good correlation between the methods and the Phase angle values were within the limits of agreement in the Bland-Altman analysis.</p><p>Conclusion</p><p>Thoracoabdominal asynchrony measured by optoelectronic plethysmography and respiratory inductive plethysmography results in similar values and has a satisfactory agreement at rest and even for different exercise intensities in these groups.</p></div

Ventilatory variables of healthy, ILD, and COPD groups at rest, L₅₀, and L₇₅ during OEP and RIP monitoring.

<p>Ventilatory variables of healthy, ILD, and COPD groups at rest, L₅₀, and L₇₅ during OEP and RIP monitoring.</p

Representation of the PhAng calculation.

<p>ΔV_RCp: upper RC variation; ΔV_AB: AB abdomen variation, m: 50% of ΔV_RCp, s: maximal excursion of ΔV_AB. PhAng: Sin Ɵ = m/s.</p

Demographic and pulmonary function characteristics of healthy, ILD, and COPD groups.

<p>Demographic and pulmonary function characteristics of healthy, ILD, and COPD groups.</p

Study protocol.

<p><b>Monitoring in the first and second phases, depending on the randomization.</b> OEP: optoelectronic plethysmography, RIP: respiratory inductive plethysmography, L50 and L75: 50% and 75% of maximal load.</p

PhAng obtained with both methods in healthy, ILD, and COPD at rest and during exercise.

<p>PhAng: Phase Angle, OEP: optoelectronic plethysmography, RIP: respiratory inductive plethysmography, ILD: interstitial lung disease, COPD: chronic obstructive pulmonary disease, L50 and L75: 50% and 75% of maximal load.</p

Regression polynomial model representing the PhAng with OEP and RIP.

<p>PhAng: Phase Angle, OEP: optoelectronic plethysmography, RIP: respiratory inductive plethysmography, ILD: interstitial lung disease, COPD: chronic obstructive pulmonary disease, L50 and L75: 50% and 75% of maximal load.</p