System and method for distinguishing blood components

Abstract

A method for measuring concentrations of blood cell components is provided. The method comprises: obtaining a blood sample from a subject, the blood sample comprising red blood cells (RBCs), white blood cells (WBCs), and platelets (PLTs); mixing the blood sample with a non-lysing aqueous solution to form a sample mixture comprising a predetermined tonicity; passing the sample mixture through a flow cell; emitting light towards the flow cell; measuring an amount of light absorbed by the RBCs; measuring an amount of light scattered by WBCs, and PLTs; determining a concentration of each of the RBCs, WBCs, and PLTs present in the sample mixture from the measured amount of light absorbed by the RBCs and scattered by the WBCs and PLTs.

1 . A system for measuring concentrations of blood cell components, the system comprising:
 an optical source configured to emit light at a predetermined wavelength;   a flow cell at least partially disposed within the light emitted by the optical source, the flow cell configured to carry a liquid sample mixture through at least a portion of the light emitted by the optical source;   a first lens disposed between the optical source and the flow cell;   a second lens disposed between the first lens and the flow cell; and   a first optical detector configured to detect light emitted by the optical source and absorbed by the sample mixture within a first cone of a first predetermined number of degrees around the incident light.   
     
     
         2 . The system according to  claim 1 , wherein the first predetermined number of degrees is from about 17 to about 26 degrees. 
     
     
         3 . The system according to  claim 2 , further comprising a second optical detector configured to detect light emitted by the optical source and side-scattered by the sample mixture outside the first cone and within a second cone of a second predetermined number of degrees around the incident light. 
     
     
         4 . The method according to  claim 3 , wherein the second predetermined number of degrees around the incident light is from about 75 degrees to about 105 degrees. 
     
     
         5 . The system according to  claim 2 , wherein the first lens comprises a first predetermined thickness and the second lens comprises a second predetermined thickness, and wherein the first predetermined thickness is less than the second predetermined thickness. 
     
     
         6 . The system according to  claim 1 , wherein the first lens comprises a thickness of about 4.2-6.2 mm and the second lens comprises a thickness of about 4.6-6.6 mm. 
     
     
         7 . The system according to  claim 1 , wherein the first lens is disposed a first predetermined distance from the second lens and the second lens is disposed a second predetermined distance from the flow cell, and wherein the first predetermined distance is greater than the second predetermined distance. 
     
     
         8 . The system according to  claim 7 , wherein the first predetermined distance is at least about two times greater than the second predetermined distance. 
     
     
         9 . The system according to  claim 7 , wherein the first predetermined distance is about 61 mm and the second predetermined distance is about 26 mm. 
     
     
         10 . The system according to  claim 1 , wherein the first lens is disposed a first predetermined distance from the second lens and the second lens is disposed a second predetermined distance from the flow cell, and wherein the first predetermined distance and the second predetermined distance are configured to provide light to the flow cell at about 400 nm to about 450 nm. 
     
     
         11 . The system according to  claim 1 , wherein the first lens and the second lens are disposed between the optical source and the flow cells at respective positions such that the flow cell receives the light from the optical source at about 400 nm to about 450 nm. 
     
     
         12 . The system according to  claim 1 , wherein the first optical detector comprises a single absorbance detector configured to determine at least one of a mean cellular hemoglobin (MCH) and a total hemoglobin (HGB) concentration by the amount of light absorbed by red blood cells (RBCs). 
     
     
         13 . The system according to  claim 1 , wherein the first optical detector is configured to collect light within the first cone in order to measure light absorbed by the red blood cells (RBCs) and light scattered by white blood cells (WBCs) and platelets (PLTs). 
     
     
         14 . The system according to  claim 13 , further comprising a second optical detector configured to detect light emitted by the optical source and side-scattered by the RBCs, WBCs, and PLTs in the sample mixture outside the first cone. 
     
     
         15 . The system according to  claim 1 , wherein the optical source emits light at a wavelength of 400 nm to 450 nm.