Needle-integrated ultrathin bioimpedance microsensor array for early detection of extravasation

Extravasation is a common complication during intravenous therapy in which infused fluids leak into the sur-rounding tissues. Timely intervention can prevent severe adverse consequences, but early detection remains an unmet clinical need because existing sensors are not sensitive to leakage occurring in small volumes (< 200 mu L) or at deep venipuncture sites. Here, an ultrathin bioimpedance microsensor array that can be integrated on intravenous needles for early and sensitive detection of extravasation is reported. The array comprises eight microelectrodes fabricated on an ultrathin and flexible polyimide substrate as well as functionalized using poly (3,4-ethylenedioxythiophene) and multi-walled carbon nanotubes. Needle integration places the array proximity to venipuncture site, and functional coating significantly reduces interface impedance, both enable the micro -sensors with high sensitivity to detect early extravasation. In vitro and in vivo experiments demonstrate the capability of the microsensors to differentiate various intravenous solutions from different tissue layers as well as identify saline extravasation with detection limit as low as 20 mu L.

Automated summary

An ultrathin bioimpedance microsensor array that can be integrated on intravenous needles is reported for early and sensitive detection of extravasation. The microsensors demonstrate high sensitivity in differentiating various intravenous solutions in different tissue layers, and can detect saline extravasation with a detection limit as low as 20 μL.