Critical Properties of a Combat Tourniquet

The committee established four major mechanical considerations  

The tourniquet must reliably occlude blood flow in large limbs up to 27 in. in 

The belt must have some form of mechanical advantage for tightening. 

The tourniquet must not have mechanical limitations that prohibit its functioning 

On the basis of these requirements, a study was initiated by the United States Army Institute of Surgical Research (USAISR) to evaluate nine commercially available tourniquets for applicability to combat use. Of these nine only the seven that were within the mechanical specifications of size and weight were tested. In a report covering the study issued in 2005, Walters et al. concluded that three of the candidate tourniquets met the requirements, the Combat Applications Tourniquet (CAT), the Special Operations Forces Tactical Tourniquet (SOFTT), both are windlass type tourniquets, and the Emergency Military Tourniquet (EMT), which is a hand-operated bulb pump pneumatic type tourniquet. These three were rated as 100% effective in blood flow occlusion. Of these three, the EMT was judged as the least painful, but it was recommended only for medical personnel and not for the field 

---