A textile-based alignment-free electrophysiological sensing sleeve for comprehensive cardiovascular monitoring

Continuous monitoring of cardiovascular risk factors in daily life is crucial for disease prevention and management. Current wearable systems, such as photoplethysmography (PPG), ultrasound, and pressure sensors, can capture some of these parameters but require precise sensor alignment over arteries. This alignment dependency complicates daily use and makes the signals highly susceptible to motion artifacts. In this work, we present a textile-based alignment-free electrophysiological sensing sleeve (TAESS) that can be comfortably worn on the upper arm. The TAESS integrates impedance plethysmography (IPG) and electrocardiography (ECG) to enable synchronized cardiovascular haemodynamic monitoring, including blood pressure (BP), cardiac output (CO), systemic vascular resistance (SVR), heart rate (HR), and other metrics. The sleeve is fabricated using silver-based conductive yarns, forming flexible, breathable, and stretchable electrodes that are produced via an automated, low-cost knitting process. Compared to commercial electrodes, TAESS demonstrates superior permeability (37.5 mg·cm^-2·h^-1), stretchability (exceeding 45% in wale direction), and thermal regulation (remaining within 0.4 °C after exercise). Most importantly, it maintains high signal fidelity and is minimally affected by radial movements, outperforming commercial PPG sensors in blood volume detection. The TAESS achieved systolic and diastolic BP prediction root-mean-squared errors of 7.05 mmHg and 5.93 mmHg, respectively, even under respiratory interference and after re-wearing. This scalable, low-cost sensing sleeve offers a robust and alignment-free solution for continuous cardiovascular monitoring, paving the way for personalized healthcare in daily life.