The authors present an easily manufactured modification of Getinge Group's Maquet Flow-i anaesthesia machine that gives it potential to be used long-term as an Intensive Care ventilator for emergency circumstances. There are some 7000 such machines in use worldwide, which could assist in increasing ICU ventilated bed capacity in a number of nations. The authors believe this modification has potential as a solution to increasing ventilator numbers for the COVID-19 pandemic, in hospitals where the Flow-i is underutilised for its designed purpose during this emergency. The technical drawing files are downloadable on the GrabCAD website and are Creative Commons (CC-BY 4.0) licensed to allow local manufacture of the modification. We welcome other Flow-i users and engineers to join us in troubleshooting this project on the associated GrabCAD discussion group during this 'pre-print' phase of research.