Over the two-year duration of this project, my primary objective was to develop a wearable patch for the rapid, out-of-hospital diagnosis of cardiovascular events. This compact patch integrates a complete electronic system for measuring biomarker concentrations and wirelessly transmitting data to nearby hospitals or emergency departments. The core innovation of the patch is a minimally invasive microneedle array designed to detect and quantify cardiac troponin I (cTnI) in the interstitial fluid of the dermis layer of the skin.
The project comprises several work packages (WPs) to ensure comprehensive device design, development, and characterization. In the first WP, I explored various dimensions, structures, and fabrication techniques for implementing the microneedle arrays. After fabrication, these microneedles were characterized for their mechanical and electrical properties to ensure reliable performance. In the second WP, I developed a microneedle-based biosensor for detecting and quantifying cTnI in interstitial fluid (ISF). This WP also involved extensive characterization of the microneedles as biosensors, evaluating their functionality in terms of dose-response, calibration curve extraction, the limit of detection, and turnaround time. In the third WP, complete system integration was developed to enable wireless data interrogation of the microneedle array without needing benchtop or laboratory-based equipment, paving the way for out-of-hospital monitoring. Then, I extended the device's application to real-life scenarios by demonstrating the functionality of the wearable patch on live animal models, ensuring its operational efficacy in a practical environment.
The European Society of Cardiology (ESC) identifies cardiovascular diseases (CVD)—primarily heart attacks—as the leading cause of death in Europe, accounting for 36% of all fatalities. The economic burden of heart attacks alone is estimated to cost the EU economy around €210 billion annually. Many of these costs and lives lost could be mitigated with tools for continuous monitoring and early diagnosis of heart attacks. Currently, the absence of such technology prevents immediate diagnosis, often missing the critical "golden hour" after a heart attack's onset when emergency medical intervention could significantly reduce mortality and severe complications. During the COVID-19 pandemic, data from the European Heart Network showed a 50% decrease in the number of heart attack cases presented at hospitals, highlighting the urgent need for at-home diagnostic tools. Existing commercial cardiac biomarker analyzers, such as i-STAT, Dimension Vista, AQT90, Elecsys, ACS:180, and the Cardiac Reader System, require the patient to be physically present in an emergency department, critical care unit or laboratory—this delay in diagnosis results in valuable time lost beyond the golden hour. While state-of-the-art cardiac biosensors focus on improving limit-of-detection, time-to-result, accuracy, and cost-effectiveness for clinical settings, there is a critical need for wearable devices that offer continuous health monitoring outside the hospital. Wearable biosensors can non-invasively sample physiological signals, providing crucial information for health monitoring and early diagnosis. Recent advancements in integrating Internet of Things (IoT) technology with biosensors are expected to revolutionize personalized healthcare by making it more accessible and economically sustainable. In the past decade, advancements in micromachining and biosensing, coupled with wireless communication technologies, have enabled the development of non-invasive or minimally invasive wireless biosensing patches with significant potential for practical applications. Due to their ease of use, low cost, rapid response, and data connectivity, wireless patch biosensors are ideal for personalized heart attack monitoring at home. However, this technology has not yet been applied specifically for heart attack monitoring.
This project aims to design, fabricate, characterize, and practically demonstrate a wireless patch biosensor for detecting cTnI for early heart attack diagnosis. This technology aligns with the European Heart Association's action plan on heart attack prevention and the Horizon 2020 health goal of "better health and care, economic growth, and sustainable health systems."
