System and method for extracting physiological information from remotely detected electromagnetic radiation

Abstract

The present invention relates to a device and a method for extracting physiological information indicative of at least one health symptom from remotely detected electromagnetic radiation. The device comprises an interface ( 20 ) for receiving a data stream comprising remotely detected image data representing an observed region comprising at least one subject of interest ( 12 ), wherein the image data comprises wavelength-dependent image information, wherein the wavelength-dependent image information is composed of at least two color channels ( 96, 98, 100 ) representative of respective wavelength portions; an image processor ( 22 ) for detecting channel signal strength information for at least two of the at least two color channels ( 96, 98, 100 ); and a data comparison unit ( 24 ) for comparing detected channel signal strengths with respective reference values.

1 . Remote photoplethysmographic monitoring system for extracting physiological information indicative of at least one health symptom from remotely detected electromagnetic radiation, comprising:
 an interface for receiving a data stream comprising remotely detected video data representing an observed region comprising at least one subject of interest, wherein the video data comprises wavelength-dependent image information, wherein the wavelength-dependent image information is composed of at least two color channels representative of respective wavelength portions;   an image processor for detecting relative channel signal strength information for at least two of the at least two color channels; and   a data comparison unit for comparing detected relative channel signal strengths with respective reference values obtained from reference data generated by monitoring healthy subjects, wherein the data comparison unit is further configured for determining a ratio of the detected relative channel signal strengths of at least two of the at least two color channels and for comparing the ratio of the relative channel signal strengths with a reference ratio; and   a symptom analyzer for deriving blood composition-indicative information from the comparison of actual relative channel signal strengths with the reference values.   
     
     
         2 . System as claimed in  claim 1 , wherein the at least two color channels are associated with a color model, the color model being based on a color model convention allocating respective wavelength portions to the at least two color channels. 
     
     
         3 . System as claimed in  claim 2 , wherein the color model is a color space based on a color space mapping convention, wherein respective wavelength portions are assigned to respective axes of the color space. 
     
     
         4 . System as claimed in  claim 3 , wherein the color space is an additive color space composed of three color channels. 
     
     
         5 . System as claimed in  claim 1 , wherein the symptom analyzer is configured for detecting a level of serum bilirubin in the subject's circulating blood under consideration of detected signal strength fluctuations. 
     
     
         6 . System as claimed in  claim 1 , wherein the symptom analyzer is configured for detecting a level of bilirubin accumulated in the subject's dermis under consideration of detected constant or quasi-constant channel signal strengths, preferably the symptom analyzer is further configured for deriving an estimate of a serum bilirubin level compared to a skin-bilirubin level. 
     
     
         7 . System as claimed in  claim 1 , wherein the symptom analyzer is configured for detecting relative channel signal strength information indicative of impending suffocation. 
     
     
         8 . System as claimed in  claim 7 , wherein the symptom analyzer is further configured for assessing oxygenation information under consideration of a ratio of the detected channel signal strengths, the oxygenation information being indicative of a ratio of hemoglobin and oxyhemoglobin in the subject's blood, and for outputting an alert signal when the ratio exceeds a reference threshold. 
     
     
         9 . System as claimed in  claim 1 , further comprising:
 an image sensor for remotely recording video data, the image sensor comprising a responsivity adapted to capture electromagnetic radiation in at least two wavelength portions corresponding to the at least two color channels.   
     
     
         10 . System as claimed in  claim 1 , further comprising:
 a pattern detector for detecting at least one indicative skin portion of the at least one subject of interest.   
     
     
         11 . System as claimed in  claim 1 , further comprising:
 a treating radiation source for emitting radiation in a particular wavelength range, wherein the treating radiation source is arranged in such a way that the emitted radiation is directed to the subject of interest, preferably the system further comprises a treatment controller for operating the treating radiation source under consideration of medical condition-indicative data generated by the data comparison unit.   
     
     
         12 . Remote photoplethysmographic monitoring method for extracting physiological information indicative of at least one health symptom from remotely detected electromagnetic radiation, comprising the steps of:
 receiving a data stream comprising video data representing an observed region comprising at least one subject of interest, wherein the video data comprises wavelength-dependent image information, wherein the wavelength-dependent image information is composed of at least two color channels representative of respective wavelength portions;   detecting relative channel signal strength information for at least two of the at least two color channels; and   comparing detected relative channel signal strengths with respective reference values obtained from reference data generated by monitoring healthy subjects, wherein the step of comparing comprises determining a ratio of the detected relative channel signal strengths of at least two of the at least two color channels and comparing the ratio of the relative channel signal strengths with a reference ratio; and   deriving blood composition-indicative information from the comparison of actual relative channel signal strengths with the reference values.   
     
     
         13 . Computer program comprising program code means for causing a computer to carry out the steps of the method as claimed in  claim 12  when said computer program is carried out on the computer.