 A longer study may help to evaluate patient tolerance of NAVA and stability over time. A longer study will also demonstrate the feasibility of NAVA to adapt to changes in respiratory drive, changes in patient status, and the interventions of health care providers. A longer time frame should help us understand the parameters for titration of NAVA settings over time and establish some indicationslimits for the future use of this promising technique. This intermediate study will generate the data necessary for the development of additional protocols to refine NAVA application and to compare NAVA to other assist modes. 