Shaili Arjani, Nathaniel Bechard, Brandon Beierle, Austin Campbell, Pierre-Luc Charron, Rui Couto, Lukesh G. Dhangaonkar, Joodi Mourhli, Alisa Nussbaumer, Santosh Roy, Levi Türk, Sujay Umarjikar, Antal Zuiderwijk
The novel coronavirus (SARS-CoV-2) swept around the globe, infecting millions of people in nearly every country in the world. The disease it causes, COVID-19, has a range of impacts on its victims, with the most serious cases suffering from severe pneumonia and lung damage.
These most severe cases require clinical intervention to keep patients alive, with a primary means initially being the use of continuous positive airway pressure (CPAP) machines and ultimately invasive ventilation to ensure the patient receives enough oxygen, and is able to breathe despite associated edema. Although it is only a small percentage of patients that require these extreme measures, the rapid rate of transmission of the virus has created situations whereby ICU and ventilator capacities that would normally be adequate for a given population size are overwhelmed and patients cannot get access to this life-saving therapy.
Because modern ventilators are complex, highly-regulated and expensive devices, their manufacture cannot be quickly scaled to meet this demand in time to be effective, especially if the production is centralised and controlled by several key market players who compete using incremental technological improvements. This creates problems of accessibility of available products. Equally problematic is that the component parts of these systems are themselves in short supply as the entire medical supply chain has been stretched by the epidemic. There are also intellectual property, distributorship, repair and other legal impediments to scaling the manufacture of ventilators or their component parts.
The community response has been for students, tech companies, and others to develop ‘ad-hoc’ ventilators to try and bridge the gap. In addition, to help solve the problem, special regulatory provisions were introduced to ease the minimal standards for “pandemic ventilators”. To date, none have been widely adopted for several reasons. First, many use ambu-bags and other equipment sourced from the same stretched medical supply chain and thus are unable to get parts. Second, clinical data has shown that patients with severe COVID-19 pneumonia have very fragile lungs, and improper ventilation can cause significant additional damage, actually worsening the outcome for the patient than if they had not received ventilation at all. Most of the ad-hoc ventilators proposed to date lack the fine control, measurement and feedback systems required to ensure they are not injurious to patients and have thus not been adopted by the medical community.
PolyVent is a diverse volunteer team of international engineers, scientists, clinicians and other professionals who have joined forces to design, build and produce a clinical-grade, open-source ventilator in response to the COVID-19 crisis and the resulting global shortage of ventilators.
Our approach is one of flexibility, with a modular design that allows modification of parts or whole modules to accommodate local supply chains and parts availabilities. Our system software can be calibrated to account for changes in key system parameters, allowing each ventilator to function as designed, even if the component parts are different from the reference specification.
Working with clinicians, we have also focused on ensuring PolyVent meets the complex clinical needs of COVID-19 patients, as well as having the flexibility to be used for treating other conditions, such that we maximize it’s efficacy now, and also leave a lasting legacy of equipment that can be used beyond the pandemic. As part of our design process, we have undertaken rigorous design reviews to ensure patient safety at every step, engineering failsafe protective features in each module. We are also planning to create VentCloud, a cloud-based data aggregation tool that will collect and analyse performance data from each PolyVent ventilator to identify failure modes, performance enhancements, and with clinician support, patient outcomes.
We realized early on that designing a ventilator, while a significant task in itself, is only half the battle. It needs to be able to be produced in the countries in which it will be used, both for logistical reasons, as well as to generate local economic benefits and create national pride. It also needs to be accepted by the medical community to be used and needs to be produced to proper quality standards, by organizations looking to help rather than profiteer. Accordingly we have designed an organizational structure built around country Clusters, which will have a leader in each target country, as well as supply chain, clinical, manufacturing and other personnel as needed. In this way we create a presence in each country PolyVent is deployed to, taking advantage of local knowledge and networks.
Current challenges that inspired us:
- Global shortage of ventilators due to the COVID-19 pandemic is causing preventable loss of life.
- Limited ventilator supply as the existing clinical ventilators are too complicated to manufacture, and improvised ones do not conform to the minimal clinical standards.
- Most of the ad-hoc ventilator designs do not meet the minimal standards or are non-scalable.
- We need alt-routes for acquiring ventilator components as the medical device manufacturers and supply chains are strained and broken at many places.
- We are facing an unprecedented crisis of our lifetime. We need to revise our production strategy to solve the logistical imbalance.
- Lack of timely delivery due to entrenched bureaucracy, IP and distributor/repair issues.
- Difficulties in global R&D aggregation and adoption into production.
PolyVent operates like a bridging initiative between multiple semi-autonomous geographical clusters, centred around one adaptable design blueprint. The idea is to allow creation of locally tailored variants of the ventilator, to increase chances of it getting to actual patients.
Check out our media coverage:
Of particular interest is this article by the EU Open Source Observatory.
- Get a VentOS driver working the proportional solenoid valve.
- Fully test the proportional solenoid valve and demonstrate complete clinical control via the PIRDS
- Demonstrate clinical control via the GUI clinical interface