A badly wounded soldier who does not receive prompt care can very easily bleed to death whilst being transported to a medical station. It is often not possible for the use of medicated gauze pads and tourniquets to stop the blood loss from a deep wound at the groin, shoulder or neck.
Undergraduates at Johns Hopkins University have developed an injectable foam system which is designed to stop bleeding from a wound where the head or a limb is connected to the torso. The invention is designed to slow down blood loss during that critical first period when the wounded soldier is being moved to a medical facility.
The new system has been developed because a gauze pad or tourniquet with a clotting agent is extremely difficult to apply to deep wounds at those body sites. It is also not easy to determine the exact source of the blood loss in these types of wounds.
The leader of the biomedical engineering student team, Sydney Rooney, said that the damage from bullets and the resultant bone fragments inside this type of wound is not always clearly visible from outside the body and a normal clotting agent may not reach the starting point of the bleeding.
She said that the main aim is to prevent wounded soldiers from losing in excess of 50% of their blood volume before they are able to be transported to a medical facility. The aim is to reach the facility within one hour as this is the time when trauma care has been proven to be most successful.
She stated that their project has been dealing with a life and death matter and that was the motivation factor for the team.
To understand what happens when a person is wounded, the students used a gel which is similar to the consistency of human tissue and rods filled with water to create ‘blood vessels’. The wounds were then carved into the gel to simulate the bleeding process. To stop this ‘blood’ loss, the students identified two liquid chemicals which, when combined, form a polyurethane foam.
Allie Sanzi, one of the team members, said the foam fills up the opening of the womb, hardens and places pressure on the cavity walls. This action should lead to effective targeting and treatment at the point where the bleeding commenced.
To maintain the stability of the chemicals used to produce the foam, the students designed special canisters. On the battleground, the soldier who is administering the treatment would have to mix the two chemicals with a mechanism which is inside the injector, which is the size of a whiteboard market, push down the plunger and insert the foam into the wound.
Paul D Danielson, medical director for paediatric surgery at All Children’s Hospital, is of the opinion that this is a very viable solution to a huge battlefield problem.
The students have been granted approval from the university to commence testing of the prototype system on animals. Testing has not yet begun, nor have tests on humans. The team is currently working with faculty advisers and medical sponsors to determine the most appropriate way in which to move forward with the project.
Image Credit: Marion Doss