LRTee: Last Resort 22mm Ventilator Tubing Splitter

thingiverse

Patients with COVID-19 in serious condition often require assisted breathing through a ventilator. As the number of patients needing ventilators grows rapidly in densely populated areas, there are not enough ventilators to support them.\r\n\r\n**Update April 14, 2020**: The LRTee design is now available on GitHub - all future updates will be hosted there.\r\n\r\nThis experimental splitter allows two patients to share a single ventilator. After testing multiple versions of other splitters, we created one with uniformly thicker walls, shorter branches, and faster printing times. It doesn't require supports or rafts and can be scaled for low-temp sterilization. The design is released as Public Domain.\r\n\r\nThis device is highly experimental, untested on humans, and requires medical professionals to monitor patients. Use at your own risk - we take no responsibility for its safety. These parts have been test-fit on anesthesia machines with ventilator capabilities and standard 22mm tubing/circuit connectors.\r\n\r\nThe general theory of using a splitter to ventilate multiple patients is explained in [COVID-19 How to Use One Ventilator to Save Multiple Lives](https://www.youtube.com/watch?v=uClq978oohY) and [A Single Ventilator for Multiple Simulated Patients to Meet Disaster Surge](https://onlinelibrary.wiley.com/doi/epdf/10.1197/j.aem.2006.05.009).\r\n\r\nThanks to these projects for informing/sharing/catalyzing design and discussion.\r\n* [3D Printed Circuit Splitter and Flow Restriction Devices for Multiple Patient Lung Ventilation](https://www.prusaprinters.org/prints/25808-3d-printed-circuit-splitter-and-flow-restriction-d)\r\n* [Ventilator Circuit Splitters - reinforced & thicker walls](https://www.prusaprinters.org/prints/27803-ventilator-circuit-splitters-reinforced-thicker-wa)\r\n\r\n**Update April 5, 2020**: More testing with annealing (via hot water bath) was performed and added as a graph. A small rise to the lower/female lip was made and a PETG printer config that produces good results is now included.\r\n\r\n**Update April 7, 2020**: PLA prints more air-tight than PETG, but can be improved by setting the "extrusion multiplier" to 1.2x and using the modified STL file that compensates for larger dimensions when printed.\r\n\r\n**Update April 8, 2020**: Four pairs of parts were produced in PETG with 1.2x extrusion multiplier and ran through the full process (from intake of printed parts at a medical facility, thorough cleaning/decontamination/sanitization, and finally testing on ventilators to verify it passes the leak test). Parts show no sign of deformation or failure and pass all primary initial tests. Next, we'll put together more concise documentation to help other medical facilities replicate the intake/cleaning/testing process.