An Inline System for Air-in-Line Detection and Automatic Occlusion in Peripheral Intravenous Therapy.

The presence of air within intravenous (IV) infusion tubing represents a recognized safety concern in routine peripheral IV therapy, particularly when infusion sources run dry or lines are left unattended. While air-in-line detection systems are available in clinical practice, these approaches commonly involve alarm-based notification following detection events. This alarm-dependent approach leaves a gap in automatic mitigation and end-of-infusion control during common clinical workflows. This work presents the design and operating principle of a compact, low-cost, battery-powered air-in-line detection system intended for peripheral IV tubing. The device employs an infrared-based sensing approach to continuously monitor tubing for the presence of air and for conditions consistent with end of infusion, such as depletion of the fluid source. Upon detection, the system automatically actuates a mechanical occlusion mechanism to halt flow while simultaneously providing notification to clinical staff. Benchtop evaluation of the proposed system demonstrated a consistent change in infrared sensor output when air was present within standard intravenous tubing compared to fluid-filled conditions. Detection of air-in-line or end-of-infusion events triggered the control logic, resulting in activation of a user notification and engagement of the motor-driven clamping mechanism designed to interrupt flow. These observations support the feasibility of integrating optical air-in-line detection with automatic flow occlusion within a compact, pump-independent inline system. Existing air-in-line detection approaches typically involve alarm generation to notify clinical staff. The proposed system addresses this limitation by combining continuous monitoring with automatic physical interruption of flow, providing an additional layer of safety and an automated end-of-infusion shutoff mechanism. This approach has the potential to improve IV safety and reduce clinical workload during routine peripheral intravenous therapy.