Self-calibrating bilirubin test card system and method

Abstract

A bilirubin assay system comprises a test card with a bilirubin test strip upon which a blood sample has been deposited, the bilirubin test strip comprising plasma from the blood sample. The bilirubin assay system further includes a mobile device with a camera, configured to capture an image of the test card that comprises the plasma on the bilirubin test strip and the set of calibration images. The system determines first and second calibration images, the first and the second calibration images having saturation values closest to a saturation value of the plasma on the bilirubin test strip. The system further determines a bilirubin level of the plasma on the bilirubin test strip based at least in part on interpolating a first color distance between the first calibration image and the plasma and a second color distance between the second calibration image and the plasma.

What is claimed is: 
     
         1 . A bilirubin assay system, comprising:
 a test card, the test card comprising: 
 a bilirubin test strip upon which a blood sample has been deposited, the bilirubin test strip comprising: 
 plasma from the blood sample; and 
 a set of calibration images; and 
 
   a mobile device, the mobile device comprising a camera, the mobile device configured to: 
 capture, with the camera, an image of the test card, the image comprising: 
 the plasma on the bilirubin test strip; and 
 the set of calibration images; 
 
 determine a first calibration image and a second calibration image, the first calibration image and the second calibration image being two calibration images of the set of calibration images having saturation values closest to a saturation value of the plasma on the bilirubin test strip; 
 determine a bilirubin level of the plasma on the bilirubin test strip based at least in part on interpolating: 
 a first color distance between the first calibration image and the plasma on the bilirubin test strip; and 
 a second color distance between the second calibration image and the plasma on the bilirubin test strip. 
 
   
     
     
         2 . The bilirubin assay system of  claim 1 , wherein the image of the test card is cropped using computer vision techniques on the mobile device. 
     
     
         3 . The bilirubin assay system of  claim 1 , wherein a color model other than saturation is used to determine the first color distance and the second color distance, the color model including RGB, CMYK, HSL, Munsell, Natural Color System, Preucil, CIELCHuv, CIELCHab, and CIECAM02. 
     
     
         4 . The bilirubin assay system of  claim 1 , wherein white calibration images indicate an orientation of the test card. 
     
     
         5 . The bilirubin assay system of  claim 1 , wherein the set of one or more calibration images have known saturation and red/green/blue (RGB) values, the known saturation and RGB values corresponding to specific concentrations of bilirubin in plasma. 
     
     
         6 . The bilirubin assay system of  claim 1 , wherein the set of one or more calibration images surrounds the bilirubin test strip. 
     
     
         7 . The bilirubin assay system of  claim 1 , wherein the image of the test card is cropped to exclude a portion of the bilirubin test strip containing red blood cells. 
     
     
         8 . A bilirubin assay system, comprising:
 a test card, the test card comprising: 
 a first hole, the first hole covered with a plastic barrier; and 
 a set of calibration images; and 
   a mobile device, the mobile device comprising a camera, the mobile device configured to: 
 capture, with the camera, an image of the test card, the image comprising: 
 a blanched region of skin as presented through the first hole; and 
 the set of calibration images; 
 
 determine a first calibration image and a second calibration image, the first calibration image and the second calibration image being two calibration images of the set of calibration images having saturation values closest to a saturation value of the blanched region of skin; 
 determine a bilirubin level of the blanched region of skin based at least in part on interpolating: 
 a first color distance between the first calibration image and the blanched region of skin; and 
 a second color distance between the second calibration image and the blanched region of skin. 
 
   
     
     
         9 . The bilirubin assay system of  claim 8 , further comprising: 
 determine a skin tone difference by determining a color distance between the blanched region of skin and a non-blanched region of skin, 
 wherein the test card further comprises a second hole, and 
 wherein the image further comprises the non-blanched region of skin as presented through the second hole; and 
   determine the bilirubin level of the skin further comprises interpolate the skin tone difference, the first color distance, and the second color distance.   
     
     
         10 . The bilirubin assay system of  claim 8 , wherein the set of one or more calibration images surrounds the first hole. 
     
     
         11 . The bilirubin assay system of  claim 8 , wherein the image of the test card is cropped using computer vision techniques on the mobile device. 
     
     
         12 . The bilirubin assay system of  claim 8 , wherein the set of one or more calibration images have known saturation and red/green/blue (RGB) values, the known saturation and RGB values corresponding to specific concentrations of bilirubin in skin. 
     
     
         13 . The bilirubin assay system of  claim 8 , wherein a color model other than saturation is used to determine the first color distance and the second color distance, the color model including RGB, CMYK, HSL, Munsell, Natural Color System, Preucil, CIELCHuv, CIELCHab, and CIECAM02. 
     
     
         14 . The bilirubin assay system of  claim 8 , wherein the test card further comprises a set of white reference color shapes, the white reference color shapes indicating an orientation of the test card. 
     
     
         15 . A bilirubin assay system, comprising:
 a test card, the test card comprising: 
 a hole, wherein a first half of the hole is covered with a plastic barrier; and 
 a set of calibration images; and 
   a mobile device, the mobile device comprising a camera, the mobile device configured to: 
 capture, with the camera, an image of the test card, the image comprising: 
 a blanched region of a tongue as presented through the first half of the hole; and 
 the set of calibration images; 
 
 determine a first calibration image and a second calibration image, the first calibration image and the second calibration image being two calibration images of the set of calibration images having saturation values closest to a saturation value of the blanched region of the tongue; 
 determine a bilirubin level of the blanched region of skin based at least in part on interpolating: 
 a first color distance between the first calibration image and the blanched region of the tongue; and 
 a second color distance between the second calibration image and the blanched region of the tongue. 
 
   
     
     
         16 . The bilirubin assay system of  claim 15 , wherein, the set of one or more calibration images surrounds the hole. 
     
     
         17 . The bilirubin assay system of  claim 15 , wherein the image of the test card is cropped using computer vision techniques on the mobile device. 
     
     
         18 . The bilirubin assay system of  claim 15 , wherein the set of one or more calibration images have known saturation and red/green/blue (RGB) values, the known saturation and RGB values corresponding to specific concentrations of bilirubin in a tongue. 
     
     
         19 . The bilirubin assay system of  claim 15 , wherein a color model other than saturation is used to determine the first color distance and the second color distance, the color model including RGB, CMYK, HSL, Munsell, Natural Color System, Preucil, CIELCHuv, CIELCHab, and CIECAM02. 
     
     
         20 . The bilirubin assay system of  claim 15 , wherein the test card further comprises a set of white reference color shapes, the white reference color shapes indicating an orientation of the test card.