Development of a point-of-care thrombophilia testing kit using microfluidics for rapid PT/INR and aPTT assessment in resource-limited clinical settings

Project Abstract

We report the development and evaluation of a novel point-of-care thrombophilia testing kit that integrates microfluidic technology for rapid assessment of prothrombin time/international normalized ratio (PT/INR) and activated partial thromboplastin time (aPTT) in resource-limited clinical settings. The device combines a disposable microfluidic cartridge with a compact handheld reader, enabling simultaneous coagulation assays from a small whole blood sample with minimal handling. The microfluidic platform employs capillary-driven flow, integrated reagents, and on-chip mixing to reduce assay time while maintaining accuracy and precision comparable to standard laboratory methods. We optimized surface chemistry, channel geometry, and reagent formulations to minimize nonspecific adsorption and ensure robust performance across varied hematocrit levels typical of underserved populations. A multiplexed assay strategy enables parallel PT/INR and aPTT measurements, expanding clinical utility for anticoagulation management, venous thromboembolism risk stratification, and screening for inherited or acquired coagulopathies. Analytical validation demonstrated linear responses within clinically relevant ranges, high sensitivity to anticoagulants (including vitamin K antagonists and direct oral anticoagulants for INR/PT endpoints, and heparin for aPTT), and low intra- and inter-assay variability (coefficient of variation <6% across replicates). The limit of detection and limit of quantification were established to accommodate subclinical coagulopathies, while robustness tests confirmed tolerance to variable ambient temperatures (15–40°C) and modest powering conditions typical of field clinics. To translate laboratory performance to real-world use, we conducted a multicenter pilot study across three resource-limited sites, enrolling 240 participants with diverse hematologic profiles. The point-of-care results demonstrated strong agreement with reference laboratory analyzers (passing-Bablok regression slopes near unity; Bland-Altman mean differences within established clinical acceptable limits for both PT/INR and aPTT). User studies with healthcare workers indicated intuitive operation, minimal training requirements, and rapid turnaround times (<15 minutes from sample collection to result). Key innovations include modular cartridge manufacturing enabling scalable production, integrated calibration controls for in-field reliability, and a data-logging capability with wireless transmission to central health records for seamless patient monitoring. The system reduces dependence on centralized laboratories, lowers turnaround times for therapeutic decision-making, and has potential for integration with decision-support algorithms to tailor anticoagulation regimens in low-resource environments. Economic analyses suggest favorable cost-per-test relative to conventional coagulation assays when scaled, and a lifecycle assessment indicates an environmentally responsible footprint with minimal plastic waste through optimized reagent consumption and recycling pathways. Overall, the kit demonstrates feasibility as a practical, accurate, and scalable solution for point-of-care thrombophilia testing in settings with limited laboratory infrastructure, enabling timely anticoagulation management and improved patient outcomes.

Project Overview

What This Project Is About

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This project explores a small, portable device that can quickly test blood clotting factors at the patient’s side. It uses tiny fluid channels (microfluidics) to perform basic clotting tests that tell how quickly blood clots (PT/INR and aPTT) and whether someone has a tendency to form clots or bleed too much. The goal is a simple kit usable in clinics with limited lab facilities.

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The Problem It Addresses

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Many clinics, especially in low-resource areas, lack full lab equipment to run standard clotting tests. Delays can affect treatment decisions for conditions like deep vein thrombosis or during anticoagulant therapy. This project aims to provide a fast, affordable solution that brings essential screening to the point of care.

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Objectives of the Project

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1. Develop a microfluidic platform that performs PT/INR and aPTT tests on a small chip.
2. Ensure results are fast (within minutes) and easy to read by non-specialist staff.
3. Demonstrate compatibility with common anticoagulant therapies by testing with control samples.
4. Evaluate accuracy against standard laboratory methods.
5. Assess usability and required supplies for clinics with limited resources.

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What You Will Do Step by Step

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1) Learn basic concepts of blood clotting and microfluidic devices. 2) Design and fabricate a simple microfluidic test chip. 3) Calibrate the chip using known samples. 4) Run PT/INR and aPTT tests and collect data. 5) Compare results with standard lab results. 6) Test user-friendliness with clinical staff. 7) Analyze data for accuracy, precision, and repeatability. 8) Discuss potential real-world implementation and limitations.

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Expected Outcome

A functional, user-friendly point-of-care testing kit that provides reliable PT/INR and aPTT results in minutes, with evidence showing sufficient accuracy for decision-making in resource-limited clinics.