The present disclosure pertains to a system and method to inexsufflate a subject. The system provides effective way to ensure that a desired lung volume is recruited when using mechanical in-exsufflation therapy. The system includes a volume operation mode such that a desired target respiratory volume for achieving a therapy objective is set and the in-exsufflation therapy delivered based on the target respiratory volume. In some embodiments, gas parameters of the pressurized flow of breathable gas are determined based on a target respiratory volume. A first respiratory cycle is delivered based on the determined gas parameters and breathing parameters of subject are determined during the first respiratory cycle of in-exsufflation. A second respiratory cycle is delivered based on the determined breathing parameters of subject and the target respiratory volume.
