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An introduction to ventilators

Arduino TeamApril 24th, 2020

This article was written by César Garcia, researcher at La Hora Maker.

SARS-CoV-2 virus has been spreading around the world since December 2019. The virus causes a coronavirus disease 2019, also known as COVID-19. This respiratory illness can cause a severe acute respiratory syndrome. Critical patients often require a ventilator during their stay at Intensive Care Units, thus the demand for ventilators has skyrocketed, with traditional manufacturers not able to keep up. Because of this, teams around the world are looking for alternatives and are creating ventilators using Arduino! 

In this new series on ventilators on the Arduino blog, we will explore these devices more detail. We will focus on the steps needed to test a ventilator. Also, on the different technologies available to move the air in a precise way. We will highlight what clinical variables doctors need. And we will interview some of the teams working on these devices. Let’s start with a brief overview of ventilators using Arduino as a control system!

At the beginning of the crisis, most people started looking for open source ventilators. There were several models available but one of the most popular was MIT Low-Cost Ventilator. This model uses an Ambu, also known as Bag Valve Mask (BVM). These bags are used by paramedics on emergencies. They press the bag to insufflate air into the patient. Given they have to press it by hand, it gets a very tiresome movement after a few minutes. MIT Low-Cost Ventilator automates this movement, saving doctors or nurses of this manual task. Even though, the paper describing the ventilator is quite useful and complete, this model did not pass any clinical trials. It was released on 2010 and nobody took development further until this year.

One of the first teams to launch a new project was the Reesistencia Team. This virtual team, based on Asturias and the Canary Islands in Spain, started working together after meeting in a Telegram group. The team consists of a doctor and several engineers, working to create a DIY open source ventilator, based on Arduino. This model is based around a Jackson Rees bag instead of an Ambu bag. This should allow the device to operate longer than the ones based on emergency bags. This team is active on Twitter, were you can find some of their initial designs.

Latest version from Reesistencia Team 24

This spark of maker ingenuity inspired several other teams to launch their own versions and prototypes in Spain. The OxyGEN team embraced rapid prototyping, starting with a machine made of scraped wood up to an industrial machine. SEAT, the Spanish car company, has produced five hundred of these devices so far. 

Initial prototypes of OxyGEN ventilador from

MIT E-Vent team has recovered the original MIT ventilator and evolved the concept further. They have done already several tests on animals to evaluate the new version. The AmboVent team from Israel has shared another BVM ventilator based on Arduino Nano, and they have provided very complete documentation.

Given the current pace of development it is very hard to document all the processes and steps involved. One of our favorites in this regard is University of Florida Health Open Source Ventilator. They have shared all design documents on their repository along with short videos. They even provide a live stream showing the stress tests for their ventilator!

Next week, we will explore the steps involved in creating a ventilator from scratch. This will help us discover common milestones and give us better tools to evaluate current designs.

Warning: Ventilators are complex machines mean to be operated by trained doctors. They need oxygen and compressed air supplies to operate. Patients are fully dependant on these machines to survive, so they need to run flawlessly. Please, explore this topic with caution and check documentation about previous trials before trying to replicate some of these projects. Not all of them have passed all required clinical trials and validations!

If you’d like to know more about ventilators, check the “Combating COVID-19 Conference” videos.

Arduino staff and Arduino community are strongly committed to support projects aimed at fighting and lessening the impact of COVID-19. Arduino products are essential for both R&D and manufacturing purposes related to the global response to Covid-19, in building digital medical devices and manufacturing processes for medical equipment and PPE. However, all prototypes and projects aimed to fight COVID-19 using Arduino open-source electronics and digital fabrication do not create any liability to Arduino (company, community and Arduino staff members). Neither Arduino nor Arduino board, staff members and community will be responsible in any form and to any extent for losses or damages of whatever nature (direct, indirect, consequential, or other) which may arise related to Arduino prototypes, Arduino electronic equipment for critical medical devices, research operations, forum and blog discussions and in general Covid-19 Arduino-based pilot and non pilot projects, independently of the Arduino control on progress or involvement in the research, development, manufacturing and in general implementation phases.