PURPOSE: For the purpose of testing different types of protective gear to shield personnel from injury due to explosions on the battlefield, sheep were subjected to mechanically induced injury. We studied lung sounds in these sheep before and after these injuries. Our hypothesis was that abnormal sounds, not present before the injury, would likely be detected in damaged lungs. Detection of these acoustic abnormalities could have the potential of providing a noninvasive means of detecting lung contusion in military personnel.
METHODS: 3 Sheep were examined with a 16 channel lung sound analyzer ( Stethographics Model 302) (STG System) prior to and after mechanically induced injury.
RESULTS: The pre-damage analysis of sheep sounds showed that sound amplitude was relatively uniform at all microphones. Few adventitious sounds are noted The post –damage analysis revealed many abnormalities in lung sound patterns. The sound amplitude was seen to be markedly increased (Fig. 1). Adventitious sounds that were similar in pattern to those in humans were also detected. In addition short squeak-like sounds were noted that are not common in humans.The abnormal sounds tended to be located over areas where the mechanically induced damage was noted in the pathologic specimens as illustrated in Fig. 2.
CONCLUSION: These observations provide evidence that lung sound analysis could help in monitoring sheep for the presence on injury in contusion studies.
CLINICAL IMPLICATIONS: These observations in sheep provide evidence that lung sound analysis could help in the detection of lung contusion in humans.
DISCLOSURE: Raymond Murphy, No Product/Research Disclosure Information; Shareholder R. Murphy is shareholder of Stethographics, Inc.; Employee R. Murphy is an employee of Stethographics, Inc.