Development of a Wearable Device for Arteriovenous Fistula Monitoring

Continuous monitoring of physiological parameters is a clinically significant approach for cardiovascular assessment. Chronic kidney disease (CKD) is a clinical status characterized by a progressive, irreversible impairment of renal function, which often requires hemodialysis through the surgical creation of a vascular access, called arteriovenous fistula (AVF). The latter requires frequent monitoring to avoid complications such as stenosis, thrombosis, and aneurysms. AVF monitoring is usually performed by doppler ultrasonography (DUS) magnetic resonance angiography (MRA) and digital subtraction angiography (DSA) which require specialized personnel and frequently is not available in a dialysis unit. In this paper will discuss the development of a wearable device based on a triboelectric sensor for monitoring of AVF in hemodialysis patients. The device is based on a layered sensor made of polyvinylidene fluoride (PVDF) and Kapton. The sensor, placed close the AVF, can evaluate the AVF status providing a triboelectric impedance cardiography (T-ICG) signal (i.e. blood acceleration). Temporal analysis of the T-ICG signals pattern evidenced significant changes in B-point morphology profile in patients with stenosis compared with patients with AVF but without stenosis. This device provides an alternative clinical method for the continuous monitoring of AVF in hemodialysis patients.