NEEDLE-ORIFICE INTRAVENOUS OXYGENATION DEVICE: CROSSFLOW AND RESIDENCE TIME EFFECTS ON MICROBUBBLE DELIVERY FOR HYPOXIA TREATMENT

Severe hypoxia remains one of the most critical challenges in emergency and critical care, where conventional lung-based oxygenation or ECMO support can be slow, invasive, or unavailable. To address this, we developed an intravenous oxygenation device that delivers oxygen directly into the bloodstream through microbubbles in saline. In this system, saline and oxygen are compressed up to 100 atm, ensuring complete gas dissolution under Henry’s law equilibrium. When this pressurized mixture is released through 32 orifice holes of 40 μm spaced radially around a needle, it generates a metastable, supersaturated flow where oxygen emerges as micro-scale bubbles. To mimic physiological flow, the needle discharge was introduced into a crossflow driven by a peristaltic pump, and the resulting bubble size distributions were measured for varying flow ratios and residence times. Higher flow ratios produced finer, more uniform bubbles, while increased residence time led to moderate growth from diffusion and coalescence. These findings identify the hydrodynamic conditions necessary to generate safe, dissolvable bubbles for rapid, lung-independent intravenous oxygen delivery. Additionally, these results support the development of a portable intravenous oxygenation device for rapid stabilization of hypoxic patients.