FIG. 2.

Examples of common devices used to induce experimental traumatic brain injury that are modified in various ways that influence outcome. (a) Illustration of a controlled cortical impact (CCI) device that delivers stereotactic guidance for impact placement and uses electromagnetic force. (b) Illustration of a CCI device that relies on delivering an impact via a pneumatically controlled piston. The nature of the injury is modifiable by various factors including the impact velocity and geometry, the size, shape, and material of the impounder. (c) Illustration of a fluid percussion device. Known variables that influence histopathological and clinical outcome include the diameter and length of the fluid-filled tube, the craniectomy size and shape to which the fluid pulse is injected. (d) Representative shock tube assembly. Dimensions of the device vary dramatically, ranging from centimeters to tens of meters in length. A membrane/diaphragm (e.g., Mylar) is inserted between the driver section and driven section. Compressed air/gas fills the driver section to a pressure that ruptures the membrane inducing a characteristic blast shock wave that travels through the driven section. Test animals or materials are placed either inside or outside the driven section. Images courtesy of Dr. C. Edward Dixon and Mr. Michael Farmer (a–c), and Dr. Douglas H.Smith (d). Color image is available online at www.liebertpub.com/neu