Abstract
CHEST 2015; 148(1): [185][186][187][188][189][190][191][192][193][194][195] e-Appendix 1:
Abstract
The OEP system (BTS Bioengineering, Milan, Italy) utilises an automatic motion analyser to detect the positions of 89 passive markers composed of a thin film of retro-reflective paper on plastic hemispheres Therefore, OEP measurements provide both absolute chest wall volumes and changes of chest wall volume, e.g. between end-inspiration and end-expiration during quiet breathing to obtain tidal volume (TV), or between otal lung capacity (TLC) and functional residual capacity (FRC) to obtain inspiratory capacity (IC). Relative compartmental volume variations within the respiratory cycle are used to calculate asynchronies between the different compartments of the chest wall.

Online Supplement e-Appendix 2: Phase shift angle Konno and Mead first used phase shift (Ɵ) to assess rib cage and abdominal asynchrony by plotting the time courses of the change in volume of the two compartments creating a Lissajou figure (figure 2) . (5) Bloch et al. adopted this approach when assessing change in chest wall asynchrony post LVRS, as did other groups that used OEP.(6-10) The degree of opening of the Lissajou figure corresponds to the phase shift angle (Ɵ). Ɵ was determined by the ratio of the distance delimited by the intercepts of the two compartmental volumes' dynamic loops on a line parallel to the x-axis at 50% of the tidal volume of the first compartmental volume (m), divided by the second compartmental tidal volume (s), as:

In this system, a phase angle of zero° represents completely synchronous movement of the compartments and 180˚ absolute asynchrony. The phase shift angle Ɵ was calculated separately for both quiet breathing and Inspiratory Capacity manoeuvres. In addition to asynchrony between RC,p, RC,a, and Ab, we were also interested in possible hemithoracic asynchronous chest wall movements as a result of unilateral intervention. Phase shift angles for the following compartmental combinations were then assessed, during both TV and IC manoeuvres:

• ƟRC; Phase shift angle between RC,p and RC,a.

• ƟDIA; Phase shift angle between RC,a and Ab.

• ƟRC and ƟDIA for the treated (or worst affected side in sham treated patients) and non-treated sides.

• ƟRC,p; Phase shift angle between treated and untreated sides of RC,p.

• ƟRC,a; Phase shift angle between treated and untreated sides of RC,a

• ƟAb; Phase shift angle between treated and untreated sides of Ab

Online Supplement 

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