Method for investigating the thrombocyte function of the blood

Abstract

A method for investigating the thrombocyte function of the blood, and particularly of platelet aggregation, wherein the following steps are carried out: a) cross-flowing an aperture with blood or blood components; b) determining the active radius of the aperture depending on time and c) evaluating the time-dependent modification of the radius as a measure for blood cell and/or thrombocyte function.

1 . A method for testing the thrombocyte function of the blood, in which there is an aperture ( 3 ), through which the blood or blood constituents flow, said method comprising the steps of:
 a) determining the effective radius of the aperture ( 3 ) as a function of the time by measuring the drop in pressure at the aperture ( 3 ) as a function of the time and determining the volumetric rate of blood flow through the aperture ( 3 ) as a function of the time;   b) calculating the hemodynamically effective radius of the aperture ( 3 ) according to the Hagen-Poiseuille law; and   c) evaluating the time-dependent change in the radius, wherein from the slope (dr/dt) of a determined straight line (dr/dt) an angle (PTGA), which exists between the determined straight line and the axis for the time (t), is determined as a measure for the thrombocyte function, or an angle (PTGA′), which exists between the determined straight line and the axis for the radius (r), is determined as a measure for the thrombocyte function.   
     
     
         2 . The method as claimed in  claim 1 , wherein on the assumption of a predefined blood platelet diameter, a platelet delay time is determined from the slope of the determined straight line (dr/dt) and the blood platelet diameter as a measure for the thrombocyte function. 
     
     
         3 . The method as claimed in  claim 1 , wherein a value (CT), at which the aperture ( 3 ) is occluded by blood cell or thrombus formation up to a predefined degree, is determined from the determined straight line as a measure for the thrombocyte function. 
     
     
         4 . The method as claimed in  claim 3 , wherein the value (CT) is predetermined for a radius of the value zero. 
     
     
         5 . The method as claimed in  claim 1 , wherein a selected section of the straight line is determined by measurement, and at least one other section of the straight line is determined by extrapolating on the basis of the selected section of the straight line. 
     
     
         6 . The method as claimed in  claim 5 , wherein the value of the straight line at the point in time zero (t=0) is determined by extrapolation, and the straight line is shifted by changing the parameters in the Hagen-Poiseuille law in such a way that the value of the radius (r) at the point in time zero (t=0) corresponds to a predefined value (V). 
     
     
         7 . The method as claimed in  claim 1 , wherein the point of intersection (P) of two or more segments of varying slopes (dr 1 /dt; dr 2 /dt) of straight lines determined during a measurement is determined as a measure for certain processes in the course of thrombus formation. 
     
     
         8 . The method as claimed in  claim 1 , wherein the correlation of the measuring points is determined with a mathematical function for the quality control of a measurement. 
     
     
         9 . The method as claimed in  claim 8 , wherein the mathematical function is a straight line. 
     
     
         10 . The method as claimed in  claim 2 , wherein a value (CT), at which the aperture ( 3 ) is occluded by blood cell or thrombus formation up to a predefined degree, is determined from the determined straight line as a measure for the thrombocyte function. 
     
     
         11 . The method as claimed in  claim 10 , wherein the value (CT) is predetermined for a radius of the value zero. 
     
     
         12 . The method as claimed in  claim 2 , wherein a selected section of the straight line is determined by measurement, and at least one other section of the straight line is determined by extrapolating on the basis of the selected section of the straight line. 
     
     
         13 . The method as claimed in  claim 12 , wherein the value of the straight line at the point in time zero (t=0) is determined by extrapolation, and the straight line is shifted by changing the parameters in the Hagen-Poiseuille law in such a way that the value of the radius (r) at the point in time zero (t=0) corresponds to a predefined value (V). 
     
     
         14 . The method as claimed in  claim 3 , wherein a selected section of the straight line is determined by measurement, and at least one other section of the straight line is determined by extrapolating on the basis of the selected section of the straight line. 
     
     
         15 . The method as claimed in  claim 14 , wherein the value of the straight line at the point in time zero (t=0) is determined by extrapolation, and the straight line is shifted by changing the parameters in the Hagen-Poiseuille law in such a way that the value of the radius (r) at the point in time zero (t=0) corresponds to a predefined value (V). 
     
     
         16 . The method as claimed in  claim 4 , wherein a selected section of the straight line is determined by measurement, and at least one other section of the straight line is determined by extrapolating on the basis of the selected section of the straight line. 
     
     
         17 . The method as claimed in  claim 16 , wherein the value of the straight line at the point in time zero (t=0) is determined by extrapolation, and the straight line is shifted by changing the parameters in the Hagen-Poiseuille law in such a way that the value of the radius (r) at the point in time zero (t=0) corresponds to a predefined value (V).