Self-adaptive epidermal blood flow sensor for high-flux vascular access monitoring of hemodialysis patients

Well-functioning vascular access (VA) is essential for hemodialysis treatment in patients with end-stage renal disease (ESRD). However, continuous and accurate monitoring of blood flow to assess high-flux VA during hospitalization or at home is not feasible for either clinical instruments or wearable sensors. Here, we report the design and preclinical validation of a high-precision, long-term, epidermal blood flow sensor that self-adapts to unavoidable sensor-mounting deviations on the skin and is compatible with individual tissue differences. Specifically, the technology is based on thermal dissipation of the skin, and improves the signal-to-error ratio surpassing 4 times when measuring high-flux blood (100–600 mL/min). In preclinical validation, the sensor is compared with the Doppler ultrasound and demonstrate a blood flow resolution of 10–50 mL/min. Furthermore, it is highly-integrated and wearable, measuring 36 × 50 mm2. The sensor paves the way for accurate, convenient, high-flux blood monitoring, offering significant potential to extend the lives of patients with ESRD.