Summary
The whole blood clotting time in glass tubes is widely used for the control of heparin
therapy. In the investigation of coagulation disorders the whole blood clotting time
is commonly done both in glass tubes and in tubes with non-wettable surfaces.
This presentation concerns the development of a portable mechanical device, the Coagulation
Timer, to perform this test. The end point is measured automatically by a photo-electric
mechanism. Only a few minutes are required to draw blood and place samples in the
machine, which may then be left unattended.
Data are presented to show that results obtained using glass tubes in the Coagulation
Timer correlate well with those of a technician using a modification of the Lee White
method. Further data are presented establishing the normal range for the whole blood
clotting time using polystyrene tubes in the Coagulation Timer.
