straight line depicted in fig2 whose slant 2 dr dt yields the growth rate when simultaneously calculating the blood platelets 39 time dependent wall shear rate that represents a measurement for blood platelets 39 transport rate it was recognized that in time the wall shear rate sharply rises from a low value at first in the area of the aperture but since the growth rate during this time remains exactly the same it can be inferred that a blood platelet delay time exists that indicates that time over which the individual blood platelets first allow an adhesion of other blood platelets in other words each blood platelet u201c determines u201d when i e thus after which lag in time or delay time other platelets may adhere to it this blood platelet delay time in connection with certain disease risks and with the development of medications is of primary importance this means that by the invention related finding of the mentioned rise dr dt i e therefore the blood platelet delay time selective evidence on disease risks e g on the risk for myocardial infarction in a patient can be gathered and for this reason medications can be selectively developed that influence the blood platelet delay time fig1 shows an existing mechanism for determining the blood platelet delay time in schematic representation in essence here according to arrow 1 blood is moved out of a supply space that is not described in any greater.