Analysis of Whole Blood Prothrombin Time/International Normalized Ratio Using Image Processing

Purpose: Patients who had undergone mechanical heart valve replacements, who have atrial fibrillation or deep vein thrombosis, need drugs called oral anticoagulants to prevent blood clotting and need regular testing of Prothrombin Time/International Normalized Ratio. Conventional laboratory approaches are time consuming, need blood component separation and a regular visit to clinical labs. The burden of PT measurement on the clinical laboratory is huge globally, which raise need for point of care, quick and user-friendly device. Methods: In this study we have proposed a handheld device based on the image processing for the PT/INR detection. Cost effective disposable strips were fabricated using thromboplastin as reagent. Device and strips were tested for 100 samples in clinical set up as per the ISO standard 17593 “Clinical laboratory testing and in vitr o medical devices - Requirements for in vitro monitoring systems for self-testing of oral anticoagulant therapy”. Results: Data was compared with the values obtained from clinical laboratory using automated coagulometer T Coag DT-100 (Trinity), and commercially available Point of Care (POC) device from Roche, Diagnostics. A correlation coefficient (r) of 0.87 & 0.77 was observed between lab vs Chitra device and Chitra device vs commercially available device, respectively. Conclusion: Clinically accepted correlation may be obtained after automation of the strip fabrication technique. The proposed device is cost effective and easy to operate and works on the novel approach of image processing. To best of our knowledge this is the first report on the image processing-based PT/INR monitoring device. blood samples were collected through venipuncture from all subjects recruited in the study for analyzing PT value of patients in laboratory and comparing the value with the device in test. Plasma was separated by centrifuging the blood samples at 1500g for 10min and analyzed on an automated coagulometer T Coag DT-100 (Trinity) using neoplastin CI Stago an ISI 1.4).