Regional diaphragm shortening measured by sonomicrometry

phragm shortening measured by sonomicrometry. J. Appl. physiol. 7’7(6): 2’791-2’796, 1994.-Diaphragmatic shortening measured by sonomicrometry has been compared in the two major anatomic segments, costal and crural. Data obtained by videofluoroscopy found a variation in subsegmental shortening within segments (Sprung et al. J. Appl. Physiol. 67: 655-662, 1989). No reproducible pattern of subsegmental shortening has emerged, and the mechanisms leading to this subsegmental variation in shortening are unknown. Therefore, we compared subsegmental shortening in both segments of the diaphragm in seven supine pentobarbital-anesthetized dogs. Seven pairs of sonomicrometer transducers were implanted in the two seg-ments, and subsegmental shortening during spontaneous breathing was measured. To determine potential mechanisms contributing to the variation in shortening, measurement