Noninvasive Biophysical Monitoring of Vascular Complications in Hemodialysis Using ECG and Bilateral PPG Measurements

Chronic kidney disease (CKD) is a progressive condition affecting millions worldwide, with a rising prevalence among younger populations due to lifestyle and genetic factors. In end-stage renal disease (ESRD), hemodialysis (HD) using an arteriovenous fistula (AVF) is essential for blood filtration. However, AVF stenosis, often caused by intimal hyperplasia, can lead to thrombosis and vascular dysfunction, requiring continuous monitoring to prevent complications. Despite the critical need for early detection, there are currently no home-based devices for assessing the degree of stenosis (DOS). To address this gap, this study proposes a wearable device and mobile application for non-invasive DOS assessment. The system collects electrocardiogram (ECG) and bilateral photoplethysmography (PPG) signals to calculate pulse transit time (PTT) differences, which correlate with stenosis severity. The results demonstrated a strong correlation (R² = 0.89) between PTT delay and DOS, confirming the feasibility of using this approach for stenosis detection. By enabling real-time, home-based monitoring, the proposed solution offers a new approach for early detection and prevention of AVF-related complications. The results demonstrate the algorithm’s potential for accurate DOS evaluation, providing a significant advancement in home-based AVF management for hemodialysis patients.