Method and apparatus for measuring analytes in blood bags
The present invention provides a method for determining a concentration of at least one analyte in a sample contained in a blood bag or in tubing in fluid communication with said blood bag, using an instrument comprising at least one calibration algorithm for the at least one analyte. The method comprises irradiating a sample in the tubing or the blood bag, using a near infrared and adjacent visible radiation source. Then measuring absorbance from the sample for the at least one analyte, and calculating a concentration of the at least one analyte using the absorbance and the at least one calibration algorithm.
1. A method for determining a concentration of one, or more than one analyte in a sample contained in a blood bag or in a tubing in fluid communication with said blood bag, using an instrument comprising one, or more than one calibration algorithm for said one, or more than one analyte, said method comprising:
a) irradiating said sample in said tubing, or said blood bag, using a radiation source of about 475 nm to about 2,700 nm;
b) measuring an absorbance of said sample; and
c) calculating a concentration of said one, or more than one analyte using said absorbance and said one, or more than one calibration algorithm.
2. The method of claim 1 , wherein said step of calculating (step c)) comprises determining values of first derivatives of two, or more than two portions of a spectrum generated from said step of measuring (step b), and incorporating said first derivatives into said one, or more than one calibration algorithm to provide said concentration.
3. The method of claim 1 wherein said blood bag, or said tubing is translucent and contains writing on its surface and irradiation is transmitted through said writing, said blood bag or said tubing, and said sample contained in said blood bag or said tubing.
4. The method of claim 1 wherein said step of irradiating (step a)) includes reflecting radiation from a reflective surface placed behind said blood bag or said tubing.
5. The method of claim 2 wherein in said step of measuring (step b)), light leakages are compensated for by measuring dark current for both sample and reference measurements.
6. The method of claim 2 , wherein said one, or more than one analyte is selected from the group consisting of haemoglobin, bilirubin, biliverdin, equivalent intralipid, methylene blue and cross-linked haemoglobin.
7. The method of claim 1 , wherein said one, or more than one analyte is selected from the group consisting of haemoglobin, bilirubin, biliverdin, equivalent intralipid, methylene blue, and cross-linked haemoglobin.
8. A method for determining a concentration of one, or more than one of haemoglobin, bilirubin, biliverdin, equivalent intralipid, methylene blue and cross-linked haemoglobinin in a sample contained in a blood bag or in a tubing in fluid communication with said blood bag, using an instrument comprising one, or more than one calibration algorithm for each of said haemoglobin, bilirubin, biliverdin, equivalent intralipid, methylene blue and cross-linked haemoglobin, said method comprising:
a) irradiating said sample in said tubing or said blood bag using a radiation source of about 475 nm to about 2,700 nm;
b) measuring an absorbance of said sample, and
c) calculating a concentration for one, or more than one of said haemoglobin, bilirubin, biliverdin, equivalent intralipid, methylene blue and cross-linked haemoglobin by determining values of first derivatives of two, or more than two portions of a spectrum generated from said step of measuring (step b), and incorporating said first derivatives into said one, or more than one calibration algorithm to provide said concentration.