An in-Situ Impedance-Based Whole Blood Anticoagulation Diagnosis Technology

Abstract

The detection of anticoagulant dosage in blood is important and necessary in clinical operations. With high anticoagulant dosage, it results in heavy bleeding during surgery. With low anticoagulant dosage, in the opposite, it leads to clotting problem. To monitor the dosage, in traditional, optical-inspection instrumentations, such as PT (Prothrombin Time) and APTT (Activated Partial Thromboplastin Time), are commonly used in hospitals. However, the processes of PT and APTT measurements are complicated and time-consuming. To address these issues, in this work, electrical impedance analysis is employed to monitor the anticoagulant dosage in the whole blood samples obtained from rats. To optimize the impedance analysis, several electrode designs are implemented and examined. Based on the experimental results, a good electrode configuration for blood coagulation measurement is tested with whole blood extracted from rats. In brief, heparin is used as the anticoagulant and different dosages were injected into the blood samples. For control experiments, at the same time, the same volume of isotonic saline were injected into the blood samples. Based on impedance spectrum analysis, both experimental sets and control sets can be recorded. Utilizing linear regression method, in addition, the regression lines of different concentration of anticoagulant dosage in the whole-blood samples can be distinguished. Comparing the slops extracted from the regressions of both experimental sets and control sets, it shows control sets' slope approaches 0, low concentration (1.5×10-3 units heparin/mL) experimental sets' slope is below 10, and high concentration (7.5×10-4 units heparin/mL) experimental sets' slope is above 10. According to the aforementioned experimental results, the more heparin adds, the larger slop value can be extracted. As a consequence, this work demonstrates a potential micro devices for fast anticoagulant dosage monitoring and it could be contributed in clinical applications.