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 at least one of 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 at least one of an amount of light absorbed by the RBCs to obtain an RBC absorption value, an amount of light scattered by WBCs to obtain a WBC scatter value, and an amount of light scattered by PLTs to obtain a PLT scatter value; and determining a concentration of at least one of the RBCs, WBCs, and PLTs present in the sample mixture.

1 . A method for measuring concentrations of blood cell components, the method comprising:
 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.   
     
     
         2 . The method according to  claim 1 , further comprising:
 measuring an amount of light side-scattered by the RBCs, WBCs, and PLTs; and   resolving overlap between the amount of light absorbed by the RBCs and the amount of light scattered by the WBCs, and PLTs from the amount of light side-scattered by the RBCs, WBCs, and PLTs in order to determine the concentration of each of the RBCs, WBCs, and PLTs.   
     
     
         3 . The method according to  claim 1 , wherein the amount of light absorbed by the RBCs is measured with the amount of light scattered by the WBCs. 
     
     
         4 . The method according to  claim 1 , wherein the RBCs are present in the sample mixture when the amount of light scattered by the WBCs is measured. 
     
     
         5 . The method according to  claim 1 , wherein the predetermined tonicity is 260-330 milliosmolar (mOsm). 
     
     
         6 . The method according to  claim 1 , further comprising distinguishing between the concentrations of RBCs, WBCs and PLTs by the amount of light absorbed by the RBCs, scattered by WBCs, and PLTs, and side-scattered by RBCs, WBCs and PLTs. 
     
     
         7 . The method according to  claim 1 , further comprising determining at least one of a mean cellular hemoglobin (MCH) and a total hemoglobin (HGB) concentration by the amount of light absorbed by the RBCs using a single absorbance detector. 
     
     
         8 . The method according to  claim 1 , further comprising detecting light absorbed by the RBCs in the sample mixture in the flow cell by a single absorption detector. 
     
     
         9 . The method according to  claim 1 , wherein the amount of light absorbed by the RBCs is detected by an absorption detector within a first cone of a first predetermined number of degrees around the incident light. 
     
     
         10 . The method according to  claim 1 , wherein the first predetermined number of degrees is from about 17 to about 26 degrees. 
     
     
         11 . 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.   
     
     
         12 . The system according to  claim 11 , wherein the first predetermined number of degrees is from about 17 to about 26 degrees. 
     
     
         13 . The system according to  claim 11 , further comprising a second optical detector configured to detect light emitted by the optical source and side-scattered by the sample mixture 
     
     
         14 . The system according to  claim 13 , wherein the light is detected outside the first cone and within a second cone of a second predetermined number of degrees around the incident light. 
     
     
         15 . The system according to  claim 11 , wherein the second predetermined number of degrees around the incident light is from about 75 degrees to about 105 degrees. 
     
     
         16 . The system according to  claim 11 , 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. 
     
     
         17 . The system according to  claim 11 , 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. 
     
     
         18 . The system according to  claim 11 , 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. 
     
     
         19 . The system according to  claim 11 , wherein the first predetermined distance is at least about two times greater than the second predetermined distance. 
     
     
         20 . The system according to  claim 11 , wherein the first predetermined distance is about 61 mm and the second predetermined distance is about 26 mm.