Automated control for detection of flow limitation

A non-transitory information-bearing medium having processor-readable information thereon, the processor-readable information to control a processor for detecting respiratory partial obstruction with a flow limitation detection device, the processor-readable information when executed by a processor, perform at least the following:

• receiving a measure of respiratory flow in the processor from a sensor;
• determining a shape index indicative of a pattern of partial obstruction from the measure of respiratory flow in the processor;
• determining a ratio of a current ventilation measure to a prior ventilation measure in the processor, the current ventilation measure calculated by dividing a total of inspired volume and expired volume of a current breathing cycle by a total of inspiratory time and expiratory time of the current breathing cycle;
• deriving a flow limitation measure as a function of the determined shape index and the determined ratio of ventilation measures in the processor;
• and
• affecting an output of the flow limitation detection device based on the derived flow limitation measure.

A method of detecting partial obstruction comprising:

• in one or more processors of a controller of a flow limitation detection device:
• receiving a measure of respiratory flow from a sensor;
• determining a shape index indicative of a pattern of partial obstruction from the measure of respiratory flow;
• determining a duty cycle measure from the measure of respiratory flow, the determined duty cycle measure being a ratio of a current duty cycle measure to a prior duty cycle measure, the current duty cycle measure being a ratio of inspiration time of a current breathing cycle to a total breath time of the current breathing cycle;
• deriving a flow limitation measure as a function of the determined shape index and the determined duty cycle measure;
• and
• affecting an output of the flow limitation detection device based on the derived flow limitation measure.

A non-transitory information-bearing medium having processor-readable information thereon, the processor-readable information to control a processor for detecting respiratory partial obstruction with a flow limitation detection device, the processor-readable information when executed by a processor, perform at least the following:

• accessing in the processor a measure of respiratory flow;
• determining in the processor a shape index indicative of a pattern of partial obstruction from the measure of respiratory flow;
• determining in the processor a duty cycle measure from the measure of respiratory flow, the determined duty cycle measure being a ratio of a current duty cycle measure to a prior duty cycle measure, the current duty cycle measure being a ratio of inspiration time of a current breathing cycle to a total breath time of the current breathing cycle;
• deriving in the processor a flow limitation measure as a function of the determined shape index and the determined duty cycle measure;
• and
• affecting an output of the flow limitation detection device based on the derived flow limitation measure.

A method of determining a treatment setting for a respiratory treatment device comprising:

• in one or more processors of a controller of a respiratory treatment device:
• accessing a measure of respiratory flow;
• from the measure of respiratory flow, determining a shape index representing a degree of partial obstruction;
• from the measure of respiratory flow, determining a ratio of ventilation measures representing a degree of change in ventilation, the ratio of ventilation measures being a ratio of a current ventilation measure to a prior ventilation measure, the current ventilation measure calculated by dividing a total of inspired volume and expired volume of a current breathing cycle by a total of inspiratory time and expiratory time of the current breathing cycle;
• calculating a treatment setting for the controller of the respiratory treatment device as a proportional function of both the degree of partial obstruction and the degree of change in ventilation;
• and
• setting the controller of the respiratory treatment device to control a treatment with the calculated treatment setting.