Auto-titration pressure support system and method of using same

An auto-titration pressure support system comprising:

• a pressure generating system adapted to generate a flow of breathing gas at a selectable pressure level;
• a patient circuit having a first end adapted to be coupled to the pressure generating system and a second end adapted to be coupled to an airway of a patient;
• a monitoring system associated with the patient circuit or the pressure generating system and adapted to measure a parameter indicative of a flow of gas in such a patient's airway and to output a flow signal indicative thereof;
• and
• a controller coupled to the monitoring system and the pressure generating system, for controlling the pressure generating system based on the output of the monitoring system, wherein the controller determines a breathing parameter from the flow signal, wherein the controller analyzes a variability of the breathing parameter and controls the pressure generating system based on a result of the variability analysis, and wherein analyzing the variability of the breathing parameter includes calculating a weighted peak flow and a best-fit trend line for the weighted peak flow over a plurality of breathing cycles, and calculating a variable breathing number (VB#) as follows:
• VB
• ⁢
• #
• =
• standard
• ⁢
• ⁢
• deviation
• adjusted
• ⁢
• ⁢
• mean
• ⁢
• ⁢
• flow
• ,
• wherein the standard deviation is calculated as a standard deviation of the weighted peak flows over a plurality of breathing cycles from the best-fit trend line, and wherein the adjusted mean flow is determined based on an actual patient flow determined from the flow signal.

An auto-titration pressure support system comprising:

• a pressure generating system adapted to generate a flow of breathing gas at a selectable pressure level;
• a patient circuit having a first end adapted to be coupled to the pressure generating system and a second end adapted to be coupled to an airway of a patient;
• a monitoring system associated with the patient circuit or the pressure generating system and adapted to measure a parameter indicative of a flow of gas in such a patient's airway and to output a flow signal indicative thereof;
• and
• a controller coupled to the monitoring system and the pressure generating system, for controlling the pressure generating system based on the output of the monitoring system,
• wherein the controller determines a skewness of a patient's inspiratory waveforms from the output of the flow sensor and controls the pressure generating system according to the skewness determination, and wherein the controller determines the skewness of the inspiratory waveform by segmenting the inspiratory waveform into a first region that corresponds to a beginning portion of the inspiratory waveform and a second region that corresponds to a middle portion of the inspiratory waveform, and comparing the flow in the second region to the flow in the first region.

An auto-titration pressure support system comprising:

• a pressure generating system adapted to generate a flow of breathing gas at a selectable pressure level;
• a patient circuit having a first end adapted to be coupled to the pressure generating system and a second end adapted to be coupled to an airway of a patient;
• a monitoring system associated with the patient circuit or the pressure generating system and adapted to measure a parameter indicative of a flow of gas in such a patient's airway and to output a flow signal indicative thereof;
• and
• a controller coupled to the monitoring system and the pressure generating system, for controlling the pressure generating system based on the output of the monitoring system, wherein the controller is programmed determine whether the patient is experiencing a central apnea/hypopnea or an obstructive/restrictive apnea/hypopnea by monitoring one or more of the following:
• (1) at least one shape parameter associated with the flow of gas during an apnea/hypopnea period, and (2) a characteristic of the flow of gas at the end of the apnea/hypopnea period indicative of an increase in respiratory effort, wherein the shape parameters monitored by the controller during an apnea/hypopnea period include a flatness of an inspiratory portion of a flow waveform, a roundness of the inspiratory portion of the flow waveform, a skewness of the inspiratory portion of the flow waveform, and wherein the controller considers a patient to be experiencing an obstructive/restrictive apnea/hypopnea responsive to the inspiratory portion of the flow waveform exhibiting at least one of an increase in flatness, a decrease in roundness, and an increased skewness, otherwise the controller considers the patient to be experiencing a central apnea/hypopnea, and wherein the controller prevents a pressure increase by the pressure generating system responsive to a determination that the patient is experiencing a central apnea/hypopnea.

An auto-titration pressure support system comprising:

• a pressure generating system adapted to generate a flow of breathing gas at a selectable pressure level;
• a patient circuit having a first end adapted to be coupled to the pressure generating system and a second end adapted to be coupled to an airway of a patient;
• a monitoring system associated with the patient circuit or the pressure generating system and adapted to measure a parameter indicative of a pressure at a patient's airway, a flow of gas in such a patient's airway, or both and to output a pressure signal, a flow signal indicative thereof, respectively, or both;
• and
• a controller coupled to the monitoring system and the pressure generating system, for controlling the pressure generating system based on the output of the monitoring system, wherein the controller is programmed to:
• (1) determine whether the patient is experiencing an apnea/hypopnea based on the pressure signal or the flow signal,
• (2) set a pressure treatment limit based on a pressure at a time an apnea/hypopnea is detected,
• (3) cause the pressure generating system to increase a pressure of the flow of breathing gas delivered to a patient responsive to a current pressure being below the pressure treatment limit, and
• (4) cause the pressure generating system to decrease a pressure of the flow of breathing gas delivered to a patient responsive to a current pressure being at or above the pressure treatment limit.