System and method for controlling insufflation pressure during inexsufflation

A method of controlling a process of inexsufflating a subject with a system, the system comprising a pressure generator, one or more sensors, and one or more processors, the method comprising:

• generating and controlling, with the pressure generator, delivery of a pressurized flow of breathable gas to an airway of the subject;
• determining, with the one or more processors, a target tidal flow rate, a target tidal volume, and an insufflation pressure limit based on the output signals and information related to previous respiration by the subject;
• causing, with the one or more processors, the pressure generator to steadily increase a pressure of the pressurized flow of breathable gas such that a flow rate of the pressurized flow of breathable gas is maintained at the target tidal flow rate;
• responsive to the pressure of the pressurized flow of breathable gas reaching the insufflation pressure limit, causing, with the one or more processors, the pressure generator to maintain the pressure of the pressurized flow of breathable gas at the insufflation pressure limit without maintaining the flow rate at the target tidal flow rate, wherein the insufflation pressure limit is reached as a result of steadily the pressure starting at a beginning of inhalation of the subject;
• and
• responsive to a determination that the target tidal volume is reached or a determination that the target tidal volume is not reached within a predetermined amount of time, causing, with the one or more processors, the pressure generator to decrease the pressure of the pressurized flow of breathable gas to a negative an exsufflation to evacuate the gas from the airway of the subject.

A system configured to inexsufflate a subject, the system comprising:

• means for generating and controlling delivery of a pressurized flow of breathable gas to the airway of the subject;
• means for generating output signals conveying information related to one or more gas parameters of the pressurized flow of breathable gas;
• means for determining a target tidal flow rate, a target tidal volume, and an insufflation pressure limit based on the output signals and information related to previous respiration by the subject;
• means for causing the pressure generator to steadily increase a pressure of the pressurized flow of breathable gas such that a flow rate of the pressurized flow of breathable gas is maintained at the target tidal flow rate;
• responsive to the pressure of the pressurized flow of breathable gas reaching the insufflation pressure limit, means for causing the pressure generator to maintain the pressure of the pressurized flow of breathable gas at the insufflation pressure limit without maintaining the flow rate at the target tidal flow rate, wherein the insufflation pressure limit is reached as a result of steadily increasing the pressure starting at a beginning of inhalation of the subject;
• and
• responsive to a determination that the target tidal volume is reached or a determination that the target tidal volume is not reached within a predetermined amount of time, means for causing the pressure generator to decrease the pressure of the pressurized flow of breathable gas to a negative an exsufflation to evacuate the gas from the airway of the subject.