Processing and detecting baseline changes in signals

Abstract

Systems and methods for detecting the occurrence of events from a signal are provided. A signal processing system may analyze baseline changes and changes in signal characteristics to detect events from a signal. The system may also detect events by analyzing energy parameters and artifacts in a scalogram of the signal. Further, the system may detect events by analyzing both the signal and its corresponding scalogram.

What is claimed is: 
     
         1 . A method for recalibrating a medical monitor based on detection of a physiological event, the method comprising:
 receiving a physiological signal from a physiological sensor attached to a subject;   calculating, using the medical monitor, a physiological parameter of the subject based on the physiological signal;   transforming, using the medical monitor, the physiological signal to generate a transformed physiological signal;   generating, using the medical monitor, a scalogram from the transformed physiological signal;   identifying, using the medical monitor, an artifact in the scalogram;   determining, using the medical monitor, at least one of size and shape of the identified artifact;   detecting, using the medical monitor, an occurrence of the physiological event based on at least one of the size and the shape of the identified artifact; and   triggering, using the medical monitor, a recalibration of the medical monitor in response to detecting the occurrence of the physiological event.   
     
     
         2 . The method of  claim 1 , wherein the medical monitor comprises at least one of a pulse oximetry monitor, an electrocardiogram monitor, an electroencephalogram, an electrogastrogram monitor, an electromyogram monitor, and a multi-parameter monitor. 
     
     
         3 . The method of  claim 1 , wherein the artifact is a high energy broad-scale cone. 
     
     
         4 . The method of  claim 1 , wherein the physiological event comprises at least one of a change in blood pressure, a change in body position, vasodilation, vasoconstriction, sympathetic nervous response, parasympathetic nervous response, and sleep arousal. 
     
     
         5 . The method of  claim 1 , further comprising calculating an energy parameter within a region of the scalogram, wherein detecting the occurrence of the physiological event is based on the energy parameter. 
     
     
         6 . The method of  claim 5 , wherein the occurrence of the physiological event is detected if at least one of the energy parameter, the size of the identified artifact, and the shape of the identified artifact exceeds a respective threshold. 
     
     
         7 . The method of  claim 5 , wherein the energy parameter comprises average energy within the region. 
     
     
         8 . The method of  claim 5 , wherein the region comprises a portion of a pulse band. 
     
     
         9 . The method of  claim 5 , wherein the region comprises a ridge of a pulse band. 
     
     
         10 . A medical monitor system, comprising:
 a physiological sensor attached to a subject configured to generate a physiological signal; and   a medical monitor configured to:
 calculate a physiological parameter of the subject based on the physiological signal; 
 transform the physiological signal to generate a transformed physiological signal; 
 generate a scalogram from the transformed physiological signal; 
 identify an artifact in the scalogram; 
 determine at least one of size and shape of the identified artifact; 
 detect an occurrence of a physiological event based on at least one of the size and the shape of the identified artifact; and 
 trigger a recalibration of the medical monitor in response to detecting the occurrence of the physiological event. 
   
     
     
         11 . The medical monitor system of  claim 10 , wherein the medical monitor comprises at least one of a pulse oximetry monitor, an electrocardiogram monitor, an electroencephalogram, an electrogastrogram monitor, an electromyogram monitor, and a multi-parameter monitor. 
     
     
         12 . The medical monitor system of  claim 10 , wherein the artifact is a high energy broad-scale cone. 
     
     
         13 . The medical monitor system of  claim 10 , wherein the physiological event comprises at least one of a change in blood pressure, a change in body position, vasodilation, vasoconstriction, sympathetic nervous response, parasympathetic nervous response, and sleep arousal. 
     
     
         14 . The medical monitor system of  claim 10 , wherein the medical monitor is further configured to calculate an energy parameter within a region of the scalogram, and wherein detecting the occurrence of the physiological event is based on the energy parameter. 
     
     
         15 . The medical monitor system of  claim 14 , wherein the medical monitor is further configured to detect the occurrence of the physiological event if at least one of the energy parameter, the size of the identified artifact, and the shape of the identified artifact exceeds a respective threshold. 
     
     
         16 . The medical monitor system of  claim 14 , wherein the energy parameter is average energy within the region. 
     
     
         17 . The medical monitor system of  claim 14 , wherein the region comprises a portion of a pulse band. 
     
     
         18 . The medical monitor system of  claim 14 , wherein the region comprises a ridge of a pulse band. 
     
     
         19 . A non-transitory computer-readable medium for use in recalibrating a medical monitor based on detection of physiological event the computer-readable medium comprising:
 computer program instructions recorded thereon for causing the medical monitor to:
 calculate a physiological parameter of the subject based on the physiological signal; 
 transform the physiological signal to generate a transformed physiological signal; 
 generate a scalogram from the transformed physiological signal; 
 identify an artifact in the scalogram; 
 determine at least one of size and shape of the identified artifact; 
 detect an occurrence of the physiological event based on at least one of the size and the shape of the identified artifact; and 
 trigger a recalibration of the medical monitor in response to detecting the occurrence of the physiological event. 
   
     
     
         20 . The non-transitory computer-readable medium system of  claim 19 , wherein the computer program instructions cause the medical monitor to:
 calculate an energy parameter within a region of the scalogram; and   detect the occurrence of the physiological event if at least one of the energy parameter, the size of the identified artifact, and the shape of the identified artifact exceeds a respective threshold.