Covers penetrating chest wounds allowing air to escape from the pleural cavity without being drawn back in.
The Russell Chest Seal is a hydrogel-based dressing with an integral low-profile valve. Its purpose is to cover penetrating chest wounds to allow air to escape from the pleural cavity without being drawn back in. The aim is to minimise lung collapses and to facilitate lung re-inflation.
Valve mechanism
Another component that makes the RCS unique is its valve mechanism. It is constructed from a thin but thought material which makes it very compliant. This allows it to open and close with very small changes in pressure. The valve is quite transparent so the dressing can be positioned accurately over the wound. A large base aperture gives some latitude for inaccurate placement in high-stress environments.
Four peripheral apertures are large enough to allow blood to escape if necessary without blocking the valve. The four apertures provide substantial redundancy: if up to three of the four holes become obstructed the valve will still remain fully operational.  
Low profile
The Russell Chest Seal has a unique low profile and flexibility. It is supplied in a pre-folded form to make it easy to store into medical packs. In low light conditions, the valve can be 'felt' to be working making it ideal for military operations.