Low-Cost Opensource Mechanical Ventilator

thingiverse

**UPDATE May 10, 2020:** We've redesigned the actuator to make it stronger and more reliable after issues with gear slipping out of place. The actuator arm's point of contact has been made smaller to improve compression. We've also added designs for our control panel including knobs for potentiometers used to control compression rate and percentage. **NOTE:** This is a prototype developed for educational purposes only, not evaluated by or approved for use by medical professionals. **Introduction:** A low-cost open-source mechanical ventilator uses an Arduino-controlled 25kg-cm servo-driven linear actuator to compress a bag valve mask. A video showing the ventilator working can be found here: https://www.youtube.com/watch?v=-b31fEGbNqg More information can be found in the full-length article regarding the design here: http://www.progressth.org/2020/04/low-cost-opensource-mechanical.html **Details:** For now, please open up the SketchUp 2017 file to see how parts are laid out for 3D printing and how they fit together. Note labels describing what each part is. We will be developing more documentation once the design is closer to something truly useable. We provide these files now so anyone interested has a starting point. We used friction welding and M3 nuts and bolts for assembly. There is also the use of 20mm PVC pipe, easily sourced in Thailand but might not be where you live. **Arduino Code:** Check out Wayne Smythe's code here: https://viralresponse.io/@progressth/low-cost-auto-ventilator/issues/code-for-the-servo-and-two-selector-knobs-to-adjust-the-rate-of-compression-and-the-length It requires an Arduino Uno and two potentiometers used to control the servo. **Credit:** The linear actuator is based on this model: https://www.thingiverse.com/thing:3170748 We beefed it up a bit, making the main drive gear bigger to allow for a longer throw of the actuator (up to 100mm). The original model is an excellent baseline for a servo-based linear actuator. The concept was widely guided by this MIT student project from 2010: https://e-vent.mit.edu/wp-content/uploads/2020/03/DMD-2010-MIT-E-Vent.pdf We changed the swinging cam to a linear actuator.