Intrinsic frequency analysis for left ventricle ejection fraction or stroke volume determination

Abstract

Hardware and software methodology are described for non-invasively monitoring cardiac health. Hemodynamic waveforms variously acquired for a subject are analyzed to calculate or approximate intrinsic frequencies in two domains in two domains across the Dicrotic Notch. Together with associated notch timing, heart rate and blood pressure values left ventricle ejection fraction and/or stroke volume can be determination.

1 - 11 . (canceled) 
     
     
         12 . A system for acquiring and analyzing a hemodynamic waveform, the system comprising:
 a light source to illuminate an area on a patient's skin;   an optical sensor to determine a skin motion waveform at the area of the patient's skin illuminated by the light source; and   a processor programmed to determine first and second intrinsic frequencies (IF) based on the measured skin motion waveform and to output a signal corresponding to at least one of left ventricle ejection fraction (LVEF) and stroke volume (SV) based on the determined first and second intrinsic frequencies.   
     
     
         13 . The system of  claim 12 , wherein the first and second intrinsic frequencies are determined using a pre-determined ejection fraction echo versus ejection fraction intrinsic frequency relationship. 
     
     
         14 . The system of  claim 12 , wherein the LVEF is calculated as a function of p min , p max , p mean , T 0  and heart rate, wherein p min , p max , p mean  are minimum, maximum, and mean systolic pressures, respectively, and T 0  is an ejection time of the left ventricle. 
     
     
         15 . The system of  claim 12 , wherein SV is calculated as a function of p min , p max , p mean , T 0  and heart rate, wherein p min , p max , p mean  are minimum, maximum, and mean systolic pressures, respectively, and T 0  is an ejection time of the left ventricle. 
     
     
         16 . The system of  claim 12 , wherein the light source is a smartphone light. 
     
     
         17 . The system of  claim 12 , wherein the optical sensor is a smartphone camera. 
     
     
         18 . A method for determining left ventricle ejection fraction (LVEF) and stroke volume (SV), the method comprising:
 illuminating an area on a patient's skin using a light source;   determining a skin motion waveform at the area of the skin illuminated by the light source using an optical sensor;   determining first and second intrinsic frequencies (IF) based on the measured skin motion waveform; and   outputting a signal corresponding to at least one of left ventricle ejection fraction (LVEF) and stroke volume (SV).   
     
     
         19 . The method of  claim 18 , wherein the first and second intrinsic frequencies are determined using a pre-determined ejection fraction echo versus ejection fraction intrinsic frequency relationship. 
     
     
         20 . The method of  claim 18 , comprising calculating LVEF as a function of p min , p max , p mean , T 0  and heart rate, wherein p min , p max , p mean  are minimum, maximum, and mean systolic pressures, respectively, and T 0  is an ejection time of the left ventricle. 
     
     
         21 . The method of  claim 18 , comprising calculating SV as a function of p min , p max , p mean , T 0  and heart rate, wherein p min , p max , p mean  are minimum, maximum, and mean systolic pressures, respectively, and T 0  is an ejection time of the left ventricle. 
     
     
         22 . The method of  claim 18 , wherein the light source is a smartphone light. 
     
     
         23 . The method of  claim 18 , wherein the optical sensor is a smartphone camera.