Think of it as laser tag with vivid, visual feedback. During combat exercises, when a soldier hits the enemy with infrared "bullets," sensors on the target's vest and helmet will trigger the discharge of plumes of dust to imitate someone getting shot by actual rounds.
For even more realism, the patent filing states that the human target could wear "sensors and discharge members at his right and left shoulders, right and left hips, chest, various positions on his back, and multiple positions on his helmet." This way, when a soldier is hit, a plume of dust would be expelled from the simulated entrance wound and a larger plume of dust could come from the exit wound.
This sensor system could also be embedded in the background to provide soldiers feedback on errant shots. For vehicles, the sensors could be connected to pyrotechnic devices to mimic explosions when, say, a military truck is hit.
The patent for "personnel casualty simulator" was granted to Stuart Segall of La Jolla, California.