Methods and systems to estimate compliance of a patient circuit in the presence of leak

A non-invasive ventilator system, comprising:

• a remote ventilator component configured to generate a gas source;
• a user interface comprising a mask configured to provide gas to a user;
• a connecting circuit configured to connect the remote ventilator component to the user interface;
• at least one sensor configured to measure at least one of gas flow or pressure;
• a low frequency, high cutoff, low pass pressure filter, wherein a pressure test signal is filtered;
• and
• a controller, the controller configured to generate the pressure test signal by filtering white noise through the low frequency, high cutoff, low pass filter;
• excite a flow source of the remote ventilator component with the generated pressure test signal for a predetermined time period, wherein excitation occurs over a series of increasing bias flows;
• obtain a measurement of at least one of a gas pressure or flow rate from the at least one sensor of the system;
• determine a vector of pressure of the obtained measurement;
• and determine, using the determined pressure vector, a parameter of a pressure flow model to indicate a compliance of a connecting circuit in the non-invasive ventilator system.