Method to characterize blood and red blood cells via erythrocyte membrane fragility quantification

Abstract

An apparatus and method for quantifying RBC fragility via stress-induced hemolysis and subsequent optical and computational analysis. While directed toward applications in blood quality control, the technology could have application in diagnosis. The apparatus comprises: a hemolysis unit; an optical analysis unit; and a computation unit. Similarly, the associated process comprises: a hemolysis step; an optical analysis step; and a computation step.

1 . A method for characterizing patient blood according to its susceptibility to mechanically-induced hemolysis, comprising:
 subjecting red blood cells to a mechanical stress, said stress being applied at one or more combination(s) of intensity and duration, thereby causing hemolysis of at least a portion of said cells;   evaluating optically said hemolysis to create one or more data point(s) corresponding to said one or more combination(s) of intensity and duration, whereby each data point reflects what fraction of cells became hemolysed upon having stress applied for a given duration at a given intensity; and   generating from said data point(s) a diagnostic indicator for a patient condition, said indicator based on a correlation of red blood cell mechanical fragility to said patient condition.   
     
     
         2 . The method of  claim 1 , wherein said patient condition is a result of a medical treatment. 
     
     
         3 . The method of  claim 2 , wherein said medical treatment employs a blood handling device. 
     
     
         4 . The method of  claim 3 , wherein said blood handling device operates in vivo. 
     
     
         5 . The method of  claim 4 , wherein said blood handling device is a ventricular assist device or an artificial heart. 
     
     
         6 . The method of  claim 3 , wherein said blood handling device operates ex vivo. 
     
     
         7 . The method of  claim 6 , wherein said blood handling device is a dialysis machine or an artificial lung. 
     
     
         8 . The method of  claim 1 , wherein said patient condition affects which blood product units are suitable for transfusion to patients having said patient condition. 
     
     
         9 . The method of  claim 8 , wherein said patient condition markedly reduces patient erythrocyte deformability. 
     
     
         10 . The method of  claim 1 , wherein said indicator is a numerical value. 
     
     
         11 . The method of  claim 10 , wherein said numerical value reflects a level of stress required to lyse a particular fraction of said red blood cells subjected thereto. 
     
     
         12 . The method of  claim 1 , wherein said data point(s) comprise a profile which has multiple data points representing what fraction of cells became hemolysed under particular stress conditions. 
     
     
         13 . The method of  claim 12 , wherein said stress conditions vary by stress duration. 
     
     
         14 . The method of  claim 12 , wherein said stress conditions vary by stress intensity. 
     
     
         15 . The method of  claim 12 , wherein said stress conditions vary by both stress duration and stress intensity. 
     
     
         16 . The method of  claim 12 , wherein said stress conditions vary by mechanical stress type. 
     
     
         17 . The method of  claim 1 , wherein said mechanical stress is a shear stress. 
     
     
         18 . The method of  claim 17 , wherein said shear stress is produced by a blood handling device whose operation causes hemolysis of at least a portion of red blood cells handled thereby. 
     
     
         19 . The method of  claim 1 , wherein said mechanical stress is provided in vitro. 
     
     
         20 . The method of  claim 19 , wherein said mechanical stress is essentially the only cause of said hemolysis.