This is a report on a methodological adaptation of the photogrammetric technique, which is used in other medical specialties, for use in analyzing respiratory movements. Photogrammetry and a model of photogrammetry designated biofotogrametria para análise da mecânica respiratória (BAMER, photogrammetric analysis of respiratory mechanics) were tested under previously described pathophysiological conditions: post-exercise dynamic hyperinflation using positive end-expiratory pressure. The BAMER model identified an increase in the thoraco-abdominal area following exercise using positive end-expiratory pressure. These results are comparable to those obtained with more robust systems of respiratory kinematics. The use of photogrammetry has value in many areas, since it produces quantitative data, being particularly relevant in pediatrics, in which monitoring resources are scarce.

Keywords: Biomechanics; Photogrammetry; Respiratory mechanics; Thoracic wall.

Objective: To test the applicability of a geometric model, adapted to the supine position, for the analysis of respiratory mechanics regarding changes in lateral thoracoabdominal areas in children with asthma. Methods: Nineteen children (mean age, 11.26 ± 1.28 years) performed isovolume maneuvers (IVMs) after maximal inspiration, followed by glottal closure and alternation of airflow between the abdominal and thoracic compartments. The maneuvers were recorded in a digital video camera placed perpendicularly to the movement plane, and the images of interest were selected. The geometric model was traced on each image based on surface landmarks of anatomical references. The traced areas were calculated using a computer program, and the results were converted into metric units (cm2) using a surface landmark of a known area. Relative contributions (RCs) of the subcompartments in relation to their original compartments and to the chest wall (CW) were calculated. Results: The model was based on 55 thoracic IVM images and 55 abdominal IVM images. Areas and subareas were compared between the maneuvers. There were significant differences in all subcompartments (p < 0.001). All of the RCs were significantly different for the CW (p < 0.001) but not for the ratios between the subcompartments and their original compartments. Conclusions: This geometric model, applied in children and adapted to the supine position, was effective in profiling changes in the thoracoabdominal silhouette during the IVMs, and the selected subdivisions were useful for the identification of areas contributing the most and the least to CW composition.

Keywords: Photogrammetry; Respiratory mechanics; Image processing, computer-assisted.