Advanced technology development for remote triage applications in bleeding combat casualties

Combat developers within the Army have envisioned development of a "wear-and-forget" physiological status monitor (PSM) that will enhance far forward capabilities for assessment of Warrior readiness for battle, as well as for remote triage, diagnosis and decision-making once Soldiers are injured. This paper will review recent work testing remote triage system prototypes in both the laboratory and during field exercises. Current PSM prototypes measure the electrocardiogram and respiration, but we have shown that information derived from these measurements alone will not be suited for specific, accurate triage of combat injuries. Because of this, we have suggested that development of a capability to provide a metric of circulating blood volume status is required for remote triage. Recently, volume status has been successfully modeled using low-level physiological signals obtained from wearable devices as input to machine-learning algorithms; these algorithms are already able to discriminate between a state of physical activity (common in combat) and that of central hypovolemia, and thus show promise for use in wearable remote triage devices.