PROCESS FOR TESTING GLOBAL HAEMOSTASIS PROPERTIES IN NATURAL BLOOD SAMPLES AND TESTING DEVICE

摘要

Global hemostasis state of blood-samples is determined. Tests are carried out on natural blood, to which no anti-clotting agents were added. Observations are made in a purpose-build instrument where blood-flow, attenuated blood flow, arrest and restart of flow can be made under conditions of gravity. The instrument is funnel shaped, the inner diameter of which is narrowed down to 20-100 micrometres. This acts as a first gap, the high shearing-force of which activates thrombocytes found in the blood-sample. The very short activation period and the high shear causes the blood sample to flow through the slit. Conditions are altered after the slit. The sehar-stress is low, the flow stagnates, and eddies are formed. Activated thrombocytes aggregate under these conditions to form thrombi. Thrombi drift into a second gap and get jammed. This process slows the flow down prior to stopping it completely. This defines the thrombocyte function of the blood-sample. Later, the fibrinolytic mechanism is activated, leading to the breakup of thrombic and the blood starts to flow again. Time elapsed between the clotted state and restart of blood flow, defines the actual blood fibrinolytic activity. The diagnostic instrument (1) is a conical synthetic receptacle (11). There is at least one ridge (2) complete with straight inner wall, running along the whole length of the receptacle's inner wall (11). There is at least one sphere (4) placed into the instrument (1) to form the constriction (3). Such a sphere is used that yields a 20-100 micrometer gap (3) between the receptacle's inner wall and the sphere.