US Patent 7615674 Battlefield chest dressing

Embodiments of a chest dressing assembly having a rigid body defining an inner chamber accessible by an opening for placement over a chest wound and one or more protected check valves on the rigid body that allow fluid, e.g., blood or air, to flow out of the chamber but prevent fluid flow into the chamber are disclosed. The body is rigid in order to prevent the dressing from being crushed when heavy clothing such as body armor covers the dressing, or in cold weather climates which require heavy clothing such as Afghanistan. Similarly, the body is shaped and the check valves are located on the body, such as in a recess, in order to prevent the same heavy clothing or body armor from interfering with the operation of the check valves.