Ventilation method and control of a ventilator based on same

Abstract

The invention provides an improved ventilation method and method for controlling a ventilator apparatus in accordance with same. More specifically, the present invention relates to a method of controlling a ventilator apparatus comprising the steps of placing a ventilator in a mode capable of adjusting airway pressure (P) and time (T), monitoring expiratory gas flow, analyzing the expiratory gas flow over time (T) to establish an expiratory gas flow pattern, and setting and/or adjusting a low time (T 2 ) based on the expiratory gas flow pattern. Alternatively, the present invention relates to a method of controlling a ventilator apparatus comprising the steps of placing a ventilator in a mode capable of adjusting airway pressure (P) and time (T), and setting a low airway pressure (P 2 ) of substantially zero cmH 2 O.

1 - 14 . (canceled) 
     
     
         15 . A method of controlling a ventilator apparatus comprising the steps of:
 a) placing a ventilator in a mode capable of adjusting airway pressure (P) and time (T);   b) monitoring expiratory gas flow and; and   c) setting a low time (T 2 ) based on the expiratory gas flow.   
     
     
         16 . The method of  claim 15 , further comprising the steps of:
 a) determining a peak expiratory gas flow;   b) adjusting T 2  to terminate when the expiratory gas flow is about 25% to about 50% of the peak expiratory gas flow.   
     
     
         17 . The method of  claim 15 , further comprising the steps of:
 a) monitoring the expiratory gas flow to determine the presence of an inflection point; and   b) adjusting T 2  to reduce the inflection point.   
     
     
         18 . The method of  claim 17 , wherein the step of adjusting T 2  comprises adjusting T 2  to substantially eliminate the inflection point. 
     
     
         19 . The method of  claim 15 , further comprising the step of maintaining an end expiratory lung volume. 
     
     
         20 . The method of  claim 15 , further comprising the step of controlling the ventilator with a control unit. 
     
     
         21 . The method of  claim 20 , wherein the control unit is programmed to analyze the expiratory gas flow over time. 
     
     
         22 . The method of  claim 15 , further comprising the steps of monitoring inspiratory gas flow and determining expiratory and inspiratory gas volume. 
     
     
         23 . The method of  claim 15 , further comprising the steps of:
 a) monitoring inspiratory gas flow,   b) determining the relationship between the expiratory and the inspiratory gas flow, and   c) setting a high airway pressure (P 1 ).   
     
     
         24 . The method of  claim 23 , wherein the step of determining the relationship comprises determining the ratio of the expiratory gas flow to the inspiratory gas flow.