How to Test a Medical Technology for Space: Trauma Sonography in Microgravity

Abstract

Preventable trauma deaths in remote environments often result from inadequate diagnosis of thoracic and abdominal injuries. Full-time habitation of the International Space Station increases the risk of traumatic injury requiring intervention. This publication describes the evaluation of trauma sonography (TS) as a noninvasive, fast and effective space-based imaging tool for diagnosing intracavity hemorrhage or visceral leakage. The NASA Space Medicine Clinical Care Capability Development Project is using a four-phase approach: 1) identify terrestrial techniques for human diagnosis through literature or ground studies; 2) develop and test a model at 1-g if microgravity evaluations are required; 3) evaluate the model in microgravity (parabolic or shuttle flight); 4) implement the technology or technique for clinical use aboard the shuttle or space station. The Phase I literature review confirmed TS as the screening tool of choice for blunt trauma in most North American hospitals. In Phase II, an animal model was developed and tested for 1-g ground studies in which either fluid or air was injected into specific anatomical sites. Trained sonographers, using standard ultrasound techniques, successfully detected the fluid and air. The animal model was then prepared for the NASA KC-135 Microgravity Laboratory (Phase III). Injection and examination procedures were synchronized to the pull-in, 0-g and pull-out segments of the parabolic flight manoeuvres. Preliminary results indicate that trauma sonography is a clinically useful tool in microgravity. Phase IV efforts will address training, procedures, hardware, and data transfer requirements necessary to implement this technique for space.