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Extracorporeal Carbon Dioxide Removal (ECCO2R) systems support patients with severe respiratory failure. Concurrent ambulation and physical therapy improve patient outcomes, but these procedures are limited by the complexity and size of the extracorporeal systems and rapid changes in patient metabolism and the acid–base balance. Here, we present the first prototype of a wearable ECCO2R system capable of adjusting to a patient's changing metabolic needs. Exhaust gas CO2 (EGCO2) partial pressure is used as an analog for blood CO2 partial pressure (pCO2). Twin blowers modulate sweep gas through the AL to achieve a desired target EGCO2. The integrated system was tested in vitro for 24 h with water, under varying simulated metabolic conditions and target EGCO2 values, and in a single test with whole blood. When challenged with changing inlet water pCO2 levels in in vitro tests, the system adjusted the sweep gas to achieve target EGCO2 within 1 min. Control runs with a fixed sweep gas (without negative feedback) demonstrated higher EGCO2 levels when challenged with higher water flow rates. A single in vitro test with whole ovine blood confirmed functionality in blood. This is the first step toward wearable ECCO2R systems that automatically respond to changing metabolism. Such devices would facilitate physical therapy and grant greater autonomy to patients. [ABSTRACT FROM AUTHOR]

The ability to cost-effectively produce large surface area microfluidic devices would bring many smallscale technologies such as microfluidic artificial lungs (μALs) from the realm of research to clinical and commercial applications. However, efforts to scale up these devices, such as by stacking multiple flat μALs have been labor intensive and resulted in bulky devices. Here, we report an automated manufacturing system, and a series of cylindrical multi-layer lungs manufactured with the system and tested for fluidic fidelity and function. A roll-to-roll (R2R) system to engrave multiple-layer devices was assembled. Unlike typical applications of R2R, the rolling process is synchronized to achieve consistent radial positioning. This allows the fluidics in the final device to be accessed without being unwrapped. To demonstrate the capabilities of the R2R manufacturing system, this method was used to manufacture multi-layer μALs. Gas and blood are engraved in alternating layers and routed orthogonally to each other. The proximity of gas and blood separated by gas permeable PDMS permits CO2 and O2 exchange via diffusion. After manufacturing, they were evaluated using water for pressure drop and CO2 gas exchange. The best performing device was tested with fresh whole bovine blood for O2 exchange. Three μALs were successfully manufactured and passed leak testing. The top performing device had 15 alternating blood and gas layers. It oxygenated blood from 70% saturation to 95% saturation at a blood flow of 3 mL min−1 and blood side pressure drop of 234 mmHg. This new roll-to-roll manufacturing system is suitable for the automated construction of multi-layer microfluidic devices that are difficult to manufacture by conventional means. With some upgrades and improvements, this technology should allow for the automatic creation of large surface area microfluidic devices that can be employed for various applications including large-scale membrane gas exchange such as clinical-scale microfluidic artificial lungs. [ABSTRACT FROM AUTHOR]