Haemostatometer: a new in vitro technique for assessing haemostatic activity of blood.

An in vitro technique to study haemostasis has been devised (the "haemostatometer") and investigated in detail. Anticoagulated blood is perfused through a teflon tube through which two holes are punched with a needle. The perfusion pressure is recorded continuously: the pressure drop after punching reflects "bleeding", and the pressure recovery indicates the pattern of the haemostatic plug formation. Platelets play the major role in the mechanism, but red cells are also necessary to arrest the bleeding. Fibrin formation does occur and contributes to the stabilisation of the haemostatic plug. Induced platelet dysfunction or bleeding diathesis due to platelet function defect can be detected by this technique. Except for the absence of any contribution from the blood vessel wall, this model provides a close ex vivo approximation to the complex process of haemostasis and possibly also thrombus formation.