Systems and methods for respiratory effort detection utilizing signal distortion

Abstract

Systems and methods for novel ventilation that allows the patient to trigger or initiate the delivery of a breath are provided. Further, systems and methods for triggering ventilation based on signal distortion of a monitored patient parameter are provided.

What is claimed is: 
     
         1 . A ventilator-implemented method for triggering inspiration, the method comprising:
 monitoring, from one or more non-invasive sensors during an exhalation phase, a physiological parameter signal of a patient receiving ventilation from a ventilator;   determining, by a microprocessor, a first residual value of the physiological parameter signal;   setting, by the microprocessor, a residual base equal to the first residual value;   determining, by the microprocessor, a second residual value of the physiological parameter signal;   determining, by the microprocessor, that a deviation between the second residual value and the residual base satisfies a trigger condition; and   triggering inspiration in response to determining that the deviation between the second residual value and the residual base satisfies the trigger condition.   
     
     
         2 . The method of  claim 1 , further comprising:
 determining a signal-to-noise ratio of the physiological parameter signal   determining, by the microprocessor, that the signal-to-noise ratio exceeds a noise threshold; and   wherein setting the residual base is based on the signal-to-noise ratio exceeding the noise threshold.   
     
     
         3 . The method of  claim 1 , wherein the trigger condition comprises a sensitivity threshold. 
     
     
         4 . The method of  claim 1 , wherein the first residual value and the second residual value occur within the exhalation phase. 
     
     
         5 . The method of  claim 1 , wherein the physiological parameter signal is a rate of change of pressure. 
     
     
         6 . A method for triggering inhalation during spontaneous or assisted ventilation of a patient on a mechanical ventilator, the method comprising:
 monitoring, during an exhalation phase, a physiological parameter signal of the patient receiving ventilation on the mechanical ventilator;   tracking, during the exhalation phase, a deviation of a residual value of the physiological parameter signal from a residual base;   detecting, based on the deviation of the residual value from the residual base, an occurrence of a distortion indicative of an inhalation effort before the physiological parameter signal has crossed a trigger baseline; and   triggering an inhalation by the mechanical ventilator as a result of the detected occurrence of the distortion.   
     
     
         7 . The method of  claim 6 , wherein the residual base is equal to a prior residual value. 
     
     
         8 . The method of  claim 6 , wherein the residual value is a difference between a current value of the physiological parameter signal and an averaged value of a defined number of recent values of the physiological parameter signal. 
     
     
         9 . The method of  claim 6 , further comprising displaying the residual value on a display screen of the mechanical ventilator. 
     
     
         10 . The method of  claim 6 , wherein the residual value and the residual base are dynamically updated during the exhalation phase. 
     
     
         11 . A medical ventilator comprising:
 a pneumatic system;   a non-invasive sensor for sensing a physiological parameter;   a processor; and   at least one memory comprising instructions that when executed by the processor cause the medical ventilator to perform operations comprising:
 monitoring, based on measurements from the non-invasive sensor during an exhalation phase, a physiological parameter signal of a patient receiving ventilation from a ventilator; 
 determining a first residual value of the physiological parameter signal; 
 setting a residual base equal to the first residual value; 
 determining a second residual value of the physiological parameter signal; 
 determining that a deviation between the second residual value and the residual base satisfies a trigger condition; and 
 triggering inspiration in response to determining that the deviation between the second residual value and the residual base satisfies the trigger condition. 
   
     
     
         12 . The medical ventilator of  claim 11 , wherein the operations further comprise:
 determining a signal-to-noise ratio of the physiological parameter signal   determining that the signal-to-noise ratio exceeds a noise threshold; and   wherein setting the residual base is based on the signal-to-noise ratio exceeding the noise threshold.   
     
     
         13 . The medical ventilator of  claim 11 , wherein the physiological parameter is an estimate of a rate of change of intrapleural pressure. 
     
     
         14 . The medical ventilator of  claim 11 , wherein the operations further comprise:
 determining a third residual value of the physiological parameter signal during an inhalation phase; and   cycling exhalation based on the third residual value.   
     
     
         15 . The medical ventilator of  claim 11 , wherein the physiological parameter is based on pressure and flow measurements.