Method and System for Processing Data from Ambulatory Physiological Monitoring

Abstract

This invention provides methods and systems for the analysis of data returned from monitoring multiple physiological parameters of a subject, especially from ambulatory multiple parameter monitoring. The methods and systems remove motion artifacts from signals and separate multiple components of single signals due to two or more physiological systems or processes. Each output signal is are preferably free from motion artifacts and reflects primarily functioning of only a single physiological system or process.

1 - 72 . (canceled) 
     
     
         73 . A system for processing physiological sensor signal data comprising:
 a wearable construction comprising one or more sensors sensitive to physiological systems or processes comprising electrocardiographic (ECG) activity and respiratory activity; and   computer memory comprising computer instructions to
 retrieve sensor signals from said wearable construction when worn by a monitored subject during periods comprising unconstrained activities, said retrieved sensor signals comprising ECG signals and respiratory signals; 
 generate an RR interval signal from said ECG signal comprising data describing successive intervals between successive R-waves; and 
 estimate respiratory components in said ECG signal by adaptively processing said ECG signals jointly with said respiratory signals in order to reduce an error signal, wherein a high frequency heart rate variability (HF HRV) signal comprises said estimated respiratory components, a low frequency heart rate variability (LF HRV) signal comprises said error signal. 
   
     
     
         74 . The system of  claim 73  wherein said instructions further de-trend said HF HRV signal and de-trend said LF HRV signal. 
     
     
         75 . The system of  claim 73  wherein said instructions further de-trend said HF HRV and de-trend said RR interval signal prior to said estimating. 
     
     
         76 . The system of  claim 73  wherein said instructions further spectrally analyze said LF HRV signal. 
     
     
         77 . The system of  claim 73  wherein said instructions further spectrally analyze said HF HRV signal. 
     
     
         78 . The system of  claim 73  wherein said respiratory signal comprises a tidal volume (Vt) signal. 
     
     
         79 . The system of  claim 78  wherein said retrieved respiratory signals comprise at least one signal from a size sensor at a rib cage (RC) level and at least one signal from a size sensor at an abdominal (AB) level, and
 wherein said instructions further determine said Vt signal by combining said RC signal and said AB signal. 
 
     
     
         80 . The system of  claim 73  wherein the instructions further low pass filter said respiratory signal using a low pass filter that passes at least those frequencies in the range of frequencies normally present in respiratory signals. 
     
     
         81 . The system of  claim 80  where said low pass filter passes signals less than approximately 1.5 Hz. 
     
     
         82 . The system of  claim 73  wherein said EEG signals and said respiratory signals are sampled and/or re-sampled at a single common sampling rate. 
     
     
         83 . The system of  claim 73  further comprising re-sampling one or more of said EEG signals and said respiratory signals at a single common sampling rate. 
     
     
         84 . The system of  claim 73  wherein said error signal is a difference between said processed ECG signals and said processed respiratory signals. 
     
     
         85 . The system of  claim 73  wherein said reducing said error signal further comprises adjusting weights of a finite impulse response filter by a least means squares technique. 
     
     
         86 . The system of  claim 73  wherein said activities comprise normal daily activities of said subject. 
     
     
         87 . The system of  claim 73  wherein said wearable construction comprises a band for encircling a body part, or a garment for all or part of the trunk, or a garment for all or part of the trunk and all or part of one or more extremities, or two or more of said bands or said garments. 
     
     
         88 . The system of  claim 73  wherein the functioning of one or more physiological systems or processes varies during subject activity, and wherein sensor signals sensitive to said varying physiological systems or processes have varying signal characteristics. 
     
     
         89 . The system of  claim 73  wherein said instructions further determine an R-R interval signal by:
 detecting R waves in an electrocardiogram signal sensitive to cardiac electrical activity; 
 discarding detected R waves that occur in an ectopic temporal location; and 
 determining said R-R interval signal. 
 
     
     
         90 . The method  claim 89  wherein said discarding further comprises interpolating a constructed R wave at the expected temporal position of a discarded ectopic R wave. 
     
     
         91 . The system of  claim 73  wherein said retrieved sensor signals are adaptively processed to enhance desired components relative to artifact components. 
     
     
         92 . A system for processing physiological sensor signal data comprising:
 a wearable construction comprising one or more sensors sensitive to physiological systems or processes comprising electrocardiographic (ECG) activity and respiratory activity; and   computer memory comprising computer instructions to
 retrieve sensor signals from said wearable construction when worn by a monitored subject during periods comprising unconstrained activities, said retrieved sensor signals comprising ECG signals and respiratory signals; 
 generate an RR interval signal from said ECG signal comprising data describing intervals between successive R-waves; 
 estimate respiratory components in said ECG signal by adaptively processing said ECG signals jointly with said respiratory signals in order to reduce an error signal, wherein a low frequency heart rate variability (LF HRV) signal comprises said error signal; and 
 estimate one or more corrected QT intervals independence on QT intervals measured in said ECG signal and on said LF HRV signal. 
   
     
     
         93 - 102 . (canceled) 
     
     
         103 . The system of  claim 92  wherein said corrected QT intervals are estimated using a formula substantially similar to: 
       
         
           
             
               
                 QT 
                 c 
               
               = 
               
                 QT 
                 
                   RR 
                 
               
             
           
         
       
     
     
         104 . The system of  claim 92  wherein said corrected QT intervals are estimated using a formula substantially similar to:
     QT   LC   =Qt+ 0.154(1− RR )
 
 
     
     
         105 - 108 . (canceled)