| 摘要 |
Detecting blood clotting (coagulation) and determining clotting time by comparing the electrical resistance of two parts of a liquid blood sample, one of which is treated to delay or prevent its coagulation. Time or rate of clotting is determined by the rate of change of electrical resistance or impedance of the sample falling to a minimum or substantially zero at the commencement of coagulation whereafter the comparative impedance begins to increase with time. Coagulation is detected by the incidence of minimum comparative impedance. Apparatus includes an electrical bridge measuring circuit having a test cell containing an untreated part of the blood sample in one arm of the bridge and a similar test cell in the other arm of the bridge containing the part of the sample which is treated to delay or prevent coagulation. Electrodes in each test cell place corresponding parts of the blood sample in series circuit with their respective arms of the electrical bridge. |
