Respiratory apparatus with improved flow-flattening detection

Abstract

In a respiratory apparatus for treatment of sleep apnea and other disorders associated with an obstruction of a patient's airway and which uses an airflow signal, an obstruction index is generated which detects the flattening of the inspiratory portion of the airflow. The obstruction index is used to differentiate normal and obstructed breathing. The obstruction index is based upon different weighting factors applied to sections of the airflow signal thereby improving sensitivity to various types of respiration obstructions.

1 . A method for determining the presence of a respiratory obstruction with a processor, the method comprising:
 accessing data samples from a signal generated by a sensor configured to detect flow, the data samples representing an inspiratory portion of a respiratory cycle; and   generating an obstruction signal in an obstruction detector of the processor when the data samples have, as a function of time, an abnormally wide initial positive lobe preceding a relatively flat portion.   
     
     
         2 . The method of  claim 1 , wherein at least some of the data samples are successive. 
     
     
         3 . The method of  claim 1 , wherein at least some of the data samples are in regular intervals. 
     
     
         4 . The method of  claim 1 , wherein magnitudes and positions of the respective positive lobes are assessed against a mean inspiration flow and a mid-inspiration point of the respective inspiration cycle. 
     
     
         5 . A method of a processor for determining the presence of a respiratory obstruction, the method comprising:
 accessing data samples from a signal generated by a sensor configured to detect flow, the data samples representing breath data; and   generating an obstruction signal in an obstruction detector with the processor when at least one breathing cycle in the data samples has, during an inspiratory portion, an abnormally wide initial positive lobe preceding a relatively flat portion.   
     
     
         6 . The method of  claim 5 , wherein at least some of the data samples are successive. 
     
     
         7 . The method of  claim 5 , wherein at least some of the data samples are in regular intervals. 
     
     
         8 . The method of  claim 5 , wherein magnitudes and positions of the respective positive lobes are assessed against a mean inspiration flow and a mid-inspiration point of the respective inspiration cycle. 
     
     
         9 . A method for determining a response for a respiratory obstruction with a processor, the method comprising:
 accessing data samples from a signal generated by a sensor configured to detect flow, the data samples representing breath data;   detecting at least one breathing cycle in the data samples that has, during an inspiratory portion, an abnormally wide initial positive lobe preceding a relatively flat portion,   calculating an obstruction index by assigning different weighting factors to inspiratory flow samples depending on a magnitude of each sample with respect to a mean inspiration flow and a time-wise position of each sample with respect to a mid-inspiration point; and   determining a command signal for activating or altering an operation of a respiratory apparatus, based on the calculated obstruction index.   
     
     
         10 . An apparatus for determining the presence of a respiratory obstruction comprising:
 a processor configured to:   access data samples from a signal generated by a sensor configured to detect flow, the data samples representing an inspiratory portion of a respiratory cycle; and   generate an obstruction signal in an obstruction detector of the processor when the data samples have, as a function of time, an abnormally wide initial positive lobe preceding a relatively flat portion.   
     
     
         11 . The apparatus of  claim 10 , wherein at least some of the data samples are successive. 
     
     
         12 . The apparatus of  claim 10 , wherein at least some of the data samples are in regular intervals. 
     
     
         13 . The apparatus of  claim 10 , wherein magnitudes and positions of the respective positive lobes are assessed against a mean inspiration flow and a mid-inspiration point of the respective inspiration cycle. 
     
     
         14 . An apparatus for determining the presence of a respiratory obstruction, the apparatus comprising:
 a processor configured to:   access data samples from a signal generated by a sensor configured to detect flow, the data samples representing breath data; and   generate an obstruction signal in an obstruction detector with the processor when at least one breathing cycle in the data samples has, during an inspiratory portion, an abnormally wide initial positive lobe preceding a relatively flat portion.   
     
     
         15 . The apparatus of  claim 14 , wherein at least some of the data samples are successive. 
     
     
         16 . The apparatus of  claim 14 , wherein at least some of the data samples are in regular intervals. 
     
     
         17 . The apparatus of  claim 14 , wherein magnitudes and positions of the respective positive lobes are assessed against a mean inspiration flow and a mid-inspiration point of the respective inspiration cycle. 
     
     
         18 . An apparatus for determining a response for a respiratory obstruction, the apparatus comprising:
 a processor configured to:   access data samples from a signal generated by a sensor configured to detect flow, the data samples representing breath data;   detect at least one breathing cycle in the data samples that has, during an inspiratory portion, an abnormally wide initial positive lobe preceding a relatively flat portion,   calculate an obstruction index by assigning different weighting factors to inspiratory flow samples depending on a magnitude of each sample with respect to a mean inspiration flow and a time-wise position of each sample with respect to a mid-inspiration point; and   determine a command signal for activating or altering an operation of a respiratory apparatus, based on the calculated obstruction index.