**Author details**

nary symptoms for the first time as adolescents while others will experience a worsening of the symptoms they have endured for years. A minimally invasive technique for repair de‐ scribed by Nuss *et al*. [45,46] involves the placement of substernal concave bar(s) that will be rotated to elevate the sternum outward. The bar is left in place for 2-3 years while the anteri‐ or chest wall remodels. The chest wall is primarily involved when there are respiratory ab‐ normalities, so the effect of repair should be assessed mainly by observing chest wall kinematics and possibly chest wall mechanics in pectus excavatum patients. A previous study carried out in adolescents with mild restrictive defect has shown that abnormalities in chest wall kinematics during maximal voluntary ventilation are not correlated with the com‐ puted tomography scan severity index, indicating the contribution of chest wall kinematics to clinical evaluation of pectus excavatum patients [47]. Should we wait 2-3 years before as‐ sessing repair effects (if any) on chest wall kinematics? Can the Nuss procedure influence timing, and kinematics of the chest wall and rib cage configuration in otherwise healthy sub‐ jects? Binazzi *et al*. [48] postulated that the repair effect based on increased chest wall end expiratory volume does not affect chest wall displacement and dynamic configuration of the rib cage. By using OEP they provided a quantitative description of chest wall kinematics be‐ fore and 6 months after the Nuss procedure at rest and during maximal voluntary ventila‐ tion in 13 subjects with pectus excavatum. An average 11% increase in chest wall volume was accommodated within the upper rib cage and to a lesser extent within the abdomen and lower rib cage. Tidal volumes did not significantly change during the study period. The re‐ pair effect on chest wall kinematics did not correlate with the Haller index of deformity at

*These data indicate that six months of the Nuss procedure do increase chest wall volume without af‐*

In conclusion, we and others have shown that use of OEP can demonstrate the following: (i) dynamic hyperinflation of the chest wall may not necessarily be the principal reason for ex‐ ercising limitation and breathlessness in COPD patients; (ii) pulmonary rehabilitation im‐ proves COPD patients' endurance and exercise-related perceptions regardless of changes in chest wall kinematics; (iii) in contrast with what is commonly believed, chest wall dynamic hyperinflation may have a salutary mechanical effect in patients with expiratory flow limita‐ tion and dynamic hyperinflation, who increase functional residual capacity because of ach‐ ieving more tidal expiratory flow; (iv) OEP provides complementary information on

Finally, there are very few reports on the use of OEP in pulmonary rehabilitation and thora‐ cic surgery in patients with chronic respiratory disease other than COPD. We hope that the

*fecting chest wall displacement and rib cage configuration.*

478 Optoelectronics - Advanced Materials and Devices

operationl volumes to that provided by spirometry.

results presented here will stimulate new contributions on this topic.

baseline.

**6. Conclusion**

Giulia Innocenti Bruni1 , Francesco Gigliotti1 and Giorgio Scano1,2

1 Section of Respiratory Rehabilitation, Fondazione Don C. Gnocchi, Florence, Italy

2 Department of Internal Medicine, Section of Immunology and Respiratory Medicine, Uni‐ versity of Florence, Florence, Italy
