Force-Sensitive Resistors for Detecting Peripheral IV Failure

Peripheral intravenous catheters fail frequently, with some estimates of failure rates as high as 50% globally. In this letter, the potential for using force-sensitive resistors (FSRs) for the detection of swelling caused by infiltration or extravasation associated with peripheral IV failures (PIVIEs) is explored. Silicone models with elastic moduli and shape consistent with that experienced by body tissue during PIVIEs were integrated into a testbed with a layer of artificial skin, transparent film dressing, FSR, and bandage. The response of an FSR manufactured by Tekscan with a standard response range up to 1 lb (4.4 N) was measured for each combination of three swelling heights (8, 12, and 18 mm) and elastic moduli (∼390, ∼490, and ∼540 kPa) and compared to the response of a precise force sensor (SingleTact 1.0 N) to determine the feasibility of using FSRs for detecting PIVIEs. Results show that the FSR resistance consistently decreases with increasing swelling height for a given elastic modulus. The coefficient of variability in the force-sensitive resistor output varies from 0.60% to 31.3% with the lowest variability occurring for the smallest amount of swelling. When filtering is introduced to remove outlying events in the FSR response, however, the range of variability drops to between 0.42% and 10.2%. While these experiments are preliminary, they nevertheless demonstrate the potential for using FSRs in single-use, disposable patches for monitoring IVs and detecting failure due to infiltration and swelling.