When a soldier is wounded on an extremity such as an arm or leg, applying a bandage and/or tourniquet to stop the bleeding is typically a fairly straight-ahead process. However, in cases where an injury is received right at the junction between an extremity and the torso – places such as the neck, shoulder or groin – things get a lot trickier. Gauze pads treated with clotting agents are often packed into the wound, although they're not always sufficient for staunching the flow. A group of students from Johns Hopkins University are working on a better alternative, in the form of a hardening foam that's injected into the wound.
The treatment system is based around a syringe-style device that contains two liquids, namely polyol and a diisocyanatein, that are kept in separate compartments – it's not unlike one of those two-part epoxy applicators.
The idea is that when a medic is treating an injured soldier on the battlefield, they use a single plunger on the device to simultaneously inject the two liquids into the wound. As the liquids mix, a chemical reaction occurs. This causes them to transform into a polyurethane foam that expands to fill the wound cavity, and then hardens.
When a soldier is wounded right at the junction between an extremity and the torso, it can be difficult to treat. A group of students from Johns Hopkins Un...