Evaluation of Thoracic Injury in Swine Model with a Noise Immune Stethoscope

Auscultation of heart and lung sounds is an important component of casualty triage, and military health care providers rely on this in order to manage an airway and to provide life saving interventions. This study evaluated the feasibility and sensitivity of a newly developed electronic stethoscope concept based on both enhanced acoustic isolation technology and on the application of a Doppler sensor (2 to 3 MHz) insensitive to noise audible to the human ear. The study used seven female Yorkshire swine. In each experiment, the noise immune stethoscope was used in both acoustic and Doppler modes to auscultate heart and lung sounds. Findings with the acoustic mode were more consistent with traditional auscultation when the endotracheal tube was placed within the esophagus and when a pnuemothorax was induced. In contrast, definitive Doppler findings were difficult to elicit and appeared neither sensitive to nor specific of the induced pathology. Overall, the acoustic mode performed well in this study while the Doppler mode was limited in its current diagnostic format. The original document contains color images.