Quantitative underwater 3D motion analysis using submerged video cameras: accuracy analysis and trajectory reconstruction

Autor(es)

Silvatti, Amanda P. ^{[1, 2]} ; Cerveri, Pietro ^[2] ; Telles, Thiago ^[1] ; Dias, Fabio A. S. ^[3] ; Baroni, Guido ^[2] ; Barros, Ricardo M. L. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Fac Phys Educ, Campinas, SP - Brazil

^[2] Politecn Milan, Dept Bioengn, I-20133 Milan - Italy

^[3] Univ Paris Est, Lab Informat Gaspard Monge, Paris - France

• Tipo de documento: Artigo Científico
• Fonte: COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING; v. 16, n. 11, p. 1240-1248, NOV 1 2013.
• Citações Web of Science: 13

Resumo

In this study we aim at investigating the applicability of underwater 3D motion capture based on submerged video cameras in terms of 3D accuracy analysis and trajectory reconstruction. Static points with classical direct linear transform (DLT) solution, a moving wand with bundle adjustment and a moving 2D plate with Zhang's method were considered for camera calibration. As an example of the final application, we reconstructed the hand motion trajectories in different swimming styles and qualitatively compared this with Maglischo's model. Four highly trained male swimmers performed butterfly, breaststroke and freestyle tasks. The middle fingertip trajectories of both hands in the underwater phase were considered. The accuracy (mean absolute error) of the two calibration approaches (wand: 0.96mm - 2D plate: 0.73mm) was comparable to out of water results and highly superior to the classical DLT results (9.74mm). Among all the swimmers, the hands' trajectories of the expert swimmer in the style were almost symmetric and in good agreement with Maglischo's model. The kinematic results highlight symmetry or asymmetry between the two hand sides, intra- and inter-subject variability in terms of the motion patterns and agreement or disagreement with the model. The two outcomes, calibration results and trajectory reconstruction, both move towards the quantitative 3D underwater motion analysis. (AU)

• Processo FAPESP: 00/01293-1 - Desenvolvimento de um sistema para análise biomecânica de movimentos humanos
• Beneficiário: Ricardo Machado Leite de Barros
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 06/02403-1 - Metodologia para análise cinemática tridimensional de volumes parciais do tronco de nadadores durante o nado
• Beneficiário: Amanda Piaia Silvatti
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 09/09359-6 - Proposição e validação de um sistema para a análise cinemática tridimensional submersa de movimentos humanos.
• Beneficiário: Amanda Piaia Silvatti
• Modalidade de apoio: Bolsas no Brasil - Doutorado