Figure 1
From: Investigation of the direct and indirect mechanisms of primary blast insult to the brain
Shock-tube experiments to isolate two potential mechanisms of primary-blast injury. (A) We considered whole-body and head-only blast-exposure configurations to investigate the effects of the direct mechanism. In the whole-body configuration setup, we mounted the rat in a custom-made sling inside the test section of the shock tube. This setup minimally restrained the animal’s motion. In the head-only configuration setup, we isolated the torso of the rat from the blast exposure by securing it to a vertical cylinder outside of the shock tube and allowed the head to protrude into the test section through a small opening. Additionally, we used flexible strings wrapped around the head to keep it in a vertical position without restraining its motion. We measured the incident, intracranial, and carotid-artery pressures at the locations shown by the white, black, and gray vertical bars, respectively, in the schematic on the right (we omitted the restraining strings to better illustrate the locations of the sensors). (B) We considered whole-body and torso-only blast-exposure configurations to investigate the effects of the indirect mechanism. In the whole-body configuration setup, we mounted the rat in a holder inside the test section of the shock tube, and used a thin cotton cloth and Velcro straps to secure the animal and minimize its motion. In the torso-only configuration setup, we isolated the head of the rat from the blast exposure by keeping it outside of the shock tube and securing the torso to a holder inside the test section. We measured the incident, intracranial, and carotid-artery pressures at the locations shown in the schematic on the right (we omitted the restraining Velcro straps to better illustrate the locations of the sensors).
