This feature makes breathing back out against the pressure of a machine easier to do.
This technology was pioneered by C-Flex, which was created by Respironics. Resmed has since introduced EPR and Invacare has introduced SoftX. However, due to patent issues, neither of these systems is fully able to reproduce the full positive effects of C-Flex. Resmed's EPR can not be run in Auto Adjusting mode, only in strait CPAP mode. Respironic's C-Flex works in both modes.
For more info see our December 2005 CPAP Newsletter which discusses the differences between EPR and C-Flex. It is the second article down.
