Meeting Abstract

123.9  Tuesday, Jan. 7 15:15  Modeling a Complex Skeleto-Muscular System in 3D: The Vocalizing Behavior of a Songbird, the Northern Cardinal (Cardinalis cardinalis) BLEVINS, C.E.*; GE, J.; SUTHERS, R.A.; HOMBERGER, D.G.; Louisiana State University, Baton Rouge; Louisiana State University, Baton Rouge; Indiana University, Bloomington; Louisiana State University, Baton Rouge zodhomb@lsu.edu

The vocal apparatus of birds is superimposed on the respiratory and feeding apparatus and comprises the semi-independently moving shoulders, neck, skull, upper jaw apparatus, mandible, hyoid apparatus, trachea, and laryngeal apparatus. The interplay of these skeleto-muscular systems was analyzed in a songbird, the Northern Cardinal, by taking advantage of recent developments in x-ray CT scanning, 3D reconstruction, imaging, animation, and microanatomy. The CT data were reconstructed and visualized with the software Avizo^® and the skeletal elements were segmented (i.e., individually marked). This 3D model was imported into the software Maya^® to be subjected to the computer animation technique called “character rigging”, which applies kinematic constraints based on a prior functional-morphological analysis, to match the movements of a living bird. The 3D model was animated by pose-matching each frame of the image sequence of an x-ray video of a singing bird in lateral view and synchronized with a regular video in dorsal view to show any sideways movements. The correct positions of the skeletal elements in the created video of the 3D model were checked by comparing them with a separate x-ray video in frontal view. The sound-track of the x-ray video allowed the matching of the exact anatomical configuration of the 3D model to each syllable of the song. This method allows the modeling of any movements of a subject and requires only one x-ray camera. Supported by NIH grant NINDS R01 NS029467 to RAS