Infusion line model for the detection of infiltration, extravasation, and other fluid flow faults

Infiltration or extravasation is the undesirable infusion of fluids and medication into the tissue space surrounding a blood vessel. If left undetected, it may cause severe tissue damage to patients requiring surgical repair or even amputation. While there are numerous patents purporting the automatic detection of infiltration, few seem to be built into current infusion devices, and none are able to distinguish between various faulty fluid flow conditions. The purpose of this study was to demonstrate that the dynamic hydraulic properties of an IV-line can be used to detect infiltration and extravasation as well as other fluid flow faults such as a kinked line or an occluded needle. A pressure step was applied to five IV-lines under five different experimental conditions; the resulting pressure curves were modeled by a third-order system. With a reliability of 92%, the system parameters were used to detect and correctly identify five different fluid flow conditions.