Invention Coach:

Robert L. Read

Public Inventor(s):

Darío Hereñú


The COVID-19 pandemic has demonstrated a clear and present need for a complete, free-libre open-source, easily repairable, widely usable, safe and effective respiratory support medical device ecosystem. Public Invention asks that you support our project to create such a system, to be called The Freespireco Project.

By “complete … respiration system,” we mean all of the composable components needed to medically and therapeutically assist people having trouble breathing for whatever reason. By “free-libre open-source,” we mean that ordinary people with ordinary skills can construct each component in the art of making electromechanical devices with the help of clear and already-published designs, plans, instructions, and regulatory documentation free for all to use and share. By “easily repairable” we mean that the owners of equipment have both the legal right and technical information to make safe repairs. Furthermore, those plans can be legally improved upon, so long as those improvements are shared under the same principles. By “safe and effective,” we mean there is a large, compelling, clearly-published body of evidence that proves the designs are safe and effective. By “widely usable,” we mean that makers have put in significant effort to ensure these devices are usable in low-resource, non-mainstream, or high-stress environments — such as by people in rural communities, people with little money, people who speak less widely spoken languages, and people in emergency situations.

The Freespireco Project recognizes that medical devices are highly regulated in many jurisdictions, and intends to support and harmonize with such regulation by facilitating regulatory approval in order to serve the health of all persons as much as possible.


The problem at hand:

The COVID-19 pandemic taught us that our lives depend on a fragile international supply chain which cannot always adapt to disruption or acute demands. The most startling example of this was the shortage of Personal Protective Equipment (PPE) worldwide. The shortage of mechanical ventilators was at times another example. Writing currently in March of 2021, the lack of therapeutic oxygen is a pressing problem.

Masks, ventilators, and oxygen concentrators are simple devices whose basic operation has been known for decades — but simple does not mean easy. Because these devices are all life-critical devices in different ways, great care must be taken to make them safe and effective. Generally the marketing of such devices requires regulatory approval from a national body tasked with ensuring that quality.

When a shortage arises, people die. Nonetheless, our planet has a vast manufacturing capability. How can it be that this manufacturing cannot be quickly repurposed to supply the demand and save lives?

Within a given community or nation there may be a lack of financial resources. In some cases, there may be sufficient money to make the devices, but there may not be the know-how needed to do so. There may be the manufacturing know-how, but there may not be designs available. There may be designs available, but there may be legal impediments. It may be possible to make the devices, but it may not be possible to make devices that have regulatory approval allowing distribution and use.


The solution proposed:

Public Invention proposes to create The Freespireco Project to create a complete, free-libre open-source, widely usable, safe and effective respiration system.

By making this system free, open, and transparent, any nation, firm, community or person will have the legal right to construct a full range of safe and effective respiration support devices. Most nations regulate the marketing of such devices. Freespireco will make obtaining regulatory approval of these devices easier by providing a large, transparent body of designs and tests. By organizing a large community of persons, firms, nonprofits and NGOs participating in Freespireco, a reliable and reusable body of human know-how will be made sharable and freely accessible to all. This is analogous to free-libre open source software projects which have conferred similar benefits to humanity in the realm of software, such as the GNU/Linux operating system, and some microcontrollers, such as the Arduino microcontroller family, both of which are based on the principles of free and open sharing.

Creating a system of composable, interoperating, and cooperating devices has enormous benefits. Today we may think in terms of individual devices to provide a particular medical function, although even now these devices have accessories and are composed in different ways to add different functionality. Particularly with respect to respiration, there are many features which are composable and cross-cutting concerns. An important example is that labored breathing (dyspnea) associated with COVID-19 is often treated with non-invasive ventilation with enriched oxygen. The production of therapeutic oxygen and the production of controlled, rhythmic flow and pressure of oxygen-enriched air and two separate functions from an engineering point of view. That is, the technology to produce oxygen is superficially different from the technology to help a patient breathe. However, upon deeper reflection, these two technologies are similar and synergize to work together. Both require careful control of flows and pressure. Both require sensing, measuring and analyzing pressure, flow, temperature, humidity, and oxygen content. A separate example of such synergy is that a non-invasive ventilator shares many functions with an ICU ventilator used for invasive ventilation, and both of these share features with a portable transport ventilator needed when a patient is moved. Furthermore, these devices are similar to more common BiPAP and CPAP machines, which are not dissimilar from PAPRs. By thinking holistically of the whole system of respiratory support possibilities as a cooperating system or ecosystem, we can make treatment safer and more effective.

A set of cooperating projects that support respiration may make respiration support cheaper and more accessible globally.


Highly active

Skills Needed

How You Can Help
The Freespireco Project needs your support. Like any project, we need encouragement and fans. Even more than software projects, we will need financial support, because the capital costs of developing hardware are higher than software. But above all, we need skilled volunteers. In addition to programmers, engineers, and inventors, we need project managers, medical experts, regulatory experts, technical writers and graphic artists.

But the easiest way to help is by making a donation.

Quarterly Goals

  • Continue to improve the PIRDS and PIRCS protocols


The Components of the System Ventilation Pieces

Although not exhaustive, let us consider some of the main components of the Respiration Ecosystem.

A mechanical ventilator helps a person breathe by pushing air and medical gases into their lungs. This may be done invasively, by sticking a tube down the patient throat, requiring sedation. Or, it may be done non-invasively, in which the patient breathes spontaneously but benefits from the assistance of the machine. Invasive ventilation and non-invasive ventilation are quite different in medical practice, but ventilation machines in each case are very similar. In fact, from an engineers point of view, all ventilators can be thought of as having four components as shown in the diagram below:


Until now, no firm has had an incentive to develop an Air Drive, Sense Module, Controller, or User Interface for a ventilator as a separate unit, because there would be no way to sell such a thing. You need all four components working together to accomplish safe and effective ventilation. Although within a firm they may have this breakdown, until now a firm has had no incentive to share either this decomposition or their implementation of the individual pieces.

However, Freespireco, a volunteer effort, has different incentives. It has every reason to treat these four components as separate projects, perhaps each with its own team, producing reusable components. In fact, Public Invention and Helpful Engineering working together have already produced a Sense Module, ad Controller, and are working on a User Interface. This is supported by several teams making ventilators which are loosely cooperating in meetings organized by these nonprofits.

So in terms of medical devices, The Freespireco Project plans to develop designs for six different but related kinds of devices:

  1. An invasive ventilator,
  2. An non-invasive ventilator,
  3. A transport ventilator,
  4. A BPAP machine,
  5. A CPAP machine,
  6. An anesthesia machine, and
  7. A PAPR. However, it will do so by making four cooperating modules:
  8. An Air Drive,
  9. A Sense Module,
  10. A Controller, and
  11. A User Interface. These modules will be sufficiently configurable to support use in any of the six respiration support machines.

Air Drive Sensor

Public Invention has already made the Sense Module, in the form of the free-libre VentMon T0.4 device, of which 25 have been distributed to teams around the world free of charge. Helpful Engineering is making the controller in the form of the VentOS open-source ventilation platform, which is well underway. Public Invention is making one variant of the Air Drive, based on bellows, being designed by the PolyVent project, which intends to use VentOS and the VentMon to deliver a complete ventilator.

Air Drive Module Breakdown

Free and Open Standards

Standards allow collaboration between teams of engineers. But even more importantly, they allow collaboration between medical researchers and clinicians. By emphasizing free and open non-proprietary standards, we foster international collaboration and collaboration between projects. Public Invention has already created two such standards, which are lightly in use and embodied in working code: The Public Invention Respiration Data Standard (PIRDS) and the Public Invention Respiration Control Standard (PIRCS). PIRDS allows recording and logging via the PIRDS-logger of the graphs of pressure and flow used by clinicians displayed (perhaps via VentDisplay) on working ventilators. PIRCS standardizes the control settings for these ventilators.

PIRDS Logger

The standards have version numbers and no doubt will evolve through augmentation over time. Although unglamorous, the disciplined maintenance of these standards is one of the most important things that Public Invention has done and will do for the Freespireco project.

Oxygen Concentrators

More disease conditions require therapeutic oxygen than mechanical ventilation. Designs which enable firms to provide safe, effective, affordable oxygen concentrators ubiquitously across the world would be enormously beneficial.Public Invention has begun a free-libre opens source oxygen concentrator called the Ox

The Sense Module (such as the VentMon) needed for ventilators is very similar to the sensing needed internally to control a pressure-swing adsorption oxygen concentrator. Additionally, the sensing needed to verify and maintain an oxygen concentrator is also similar. Thus there is direct overlap and synergy between oxygen concentrators and ventilators. The VentMon is useful for oxygen concentrators (some variations in the VentMon may be required.) Additionally, there is some overlap in the Controller and Air Drive modules as well. Thus, it makes sense for an oxygen concentrator team to cooperate with a ventilator development team.

There is also medical cooperation; therapeutic oxygen is often needed with mechanical ventilation. Thus, ensuring actual co-operation of the machines in practice by coordinating the development teams and their testing is very useful.

We can enumerate independent composable of components relating to oxygen concentration as:

  1. Pressure Swing Adsorption chambers
  2. Dryers Filters
  3. Oxygen Blenders
  4. Precision pressure release valves

Anesthesia Machines

Anesthesia machines represent an additional medical device which shares many companies with the Freespireco system. The major components of the respiration ecosystem generally have microcontrollers and thus, software. VentOS is an important beginning of this software which has been developed in a disciplined way that runs inside the devices themselves.

However, there are many functions outside the devices for clinical control and analysis, medical research, and engineering testing and maintenance. Public Invention has begun this with its standards as well as the PIRDS logger system and the VentDisplay software. More work is required, such as allowing multi-day analysis of PIRDS log files.

Minor components

Although essential, there are other minor components needed by the respiration ecosystem that deserve free-libre open source designs. These include but are not limited to:

  1. Patient Inflating Valves
  2. One-way check valves
  3. PEEP valves
  4. Emergency pop-off valves
  5. Sanitizers
  6. Heaters
  7. Humidifiers
  8. Dryers
  9. Nebulizers
  10. CO2 scrubbers

Testing, Transparency, and Trust

Testing is paramount to The Freespireco Project.

Public Invention developed the VentMon Monitor/Test before developing any air production components as an expression of this principle: Testing drives development.

We expect the number of lines of code devoted to testing to be about ten times the number of lines of code embedded in devices, and we expect this factor to gradually increase over the first few decades.

Likewise, The Freespireco Project will develop special test equipment (such as the VentMon) and test harnesses, not listed as components. Nevertheless, test equipment is of equal or greater importance than the devices being tested. We take trust through transparency as a basic principle. Code which can be freely studied and highly instrumented machines provide trustworthiness. By using extensive instrumentation and logging, the normally hidden function of the machine is fully exposed, building trust. Moreover, extensive testing of both expected and unusual cases and complete published transparency of those test results is crucial to building trust.

Repairability and Supply Chain Resilience

The ability to repair a respiration support device and supply chain resilience are intertwined so closely that they should not be separated.

The pandemic experiences has produced anecdotal reports of broken equipment in low-resource communities that might have saved lives if repairable.

“Supply Chain Resilience” does not mean each nation being able to fully construct complete devices independently of other nations, but rather the ability to obtain critical parts.

The basic approach of a modular, composable, free-libre open source eco-system means that each part can be repaired and replaced somewhat independently. If a critical part is in short supply, it can be built locally, even if under normal circumstances that would be economically inefficient.

“Trust through transparency” implies “Trust through testing”. Freespireco will design devices that can be easily tested not just at their time of deployment, but throughout their lifecycle. A device that it easy to test is likely to be easy to reliably repair.

We support the idea known as “Right to Repair”, but more importantly we plan to “Design for Repairability”. The two taken together ensure repairability.

A fully open system supports third-party testing more than closed, secretive systems. Third-party testability further generates trustworthiness.

Regulatory Approval

The Freespireco Project facilitates regulatory approval, but will not market devices itself. Rather, it will create business opportunities for other firms to use its research.

By providing full design history transparency and extensive transparently documented testing records and extensive telemetry, The Freespireco Project produces the raw material to apply for regulatory approval by bodies such as the FDA.

Developing a public commons of reusable documentation suitable for wholesale inclusion in such applications is a major goal of The Freespireco Project.


In order to create a free public commons of respirations devices that anyone can build and that strongly encourage the contribution of improvements to the public, Freespireco uses strong reciprocal, or share-alike, licenses.

Our license policy is reflected in the Public Invention Licensing Guidelines which we encourage others to reuse.

There is currently no free public commons that provides examples of application information submitted to regulatory bodies for approval. In order to create one, Public Invention has begun making the Regulatory Sunlight Agreement which is analogous to a share-alike or reciprocal license for regulatory matter.


The Freespireco Project will not seek patents. We will attempt to create a public commons which has maximum safety and effectiveness and ease of use, manufacture, and deployment. Therefore, we will avoid infringing patents wherever possible, and where necessary, clearly delineate features to allow potential manufacturers to operate without fear, uncertainty, and doubt (FUD).


The Freespireco Project expects to operate on the scale of decades, and to re-evaluate itself after each five years. We expect a complete respiration ecosystem to be saving lives within the first decade.

Research Usage

Of all potential users, medical researchers will benefit soonest from The Freespireco project because it will be a platform that accommodates both hardware and software research ideas. As a free platform, it allows a research team to create and test a new feature with maximum transparency. Researchers will also benefit from our emphasis on automated testing, extensive instrumentation, and complete documentation.

Likely Contributors

Experience has shown that it is important to lower the barriers to entry for any contributor in order to encourage many contributors.

Like any hardware project, the costs for a given contributor to get involved is higher than for a pure software project. However, the essential parts needed for a basic Freespireco ventilation system will cost between USD$1000 and USD$3000. This is low enough that academic researchers, humanitarian engineers, and makers will be able to join the project relatively easily.

The most likely contributors to The Freespireco Project will be:

  1. Humanitarian engineers, such as the tens of thousands that have joined the Slack channels of non-profits in 2020 such as Public InventionHelpful EngineeringCOSMIC, and Open Source Medical Supplies. Public Invention has strong connections to these organizations.
  2. Academic researchers using The Freespireco Project for their own research.
  3. Makers motivated primarily by the joy of creation.

Development Process

The Freespireco Project will organize and govern itself using processes honed over the last 20 years by the free software community. An exemplar of these practices is “The Apache Way” pioneered by the Apache foundation.

Vendor Neutrality

Because hardware devices are not free-as-in-free-lunch, they will usually be sold. Like The Apache Foundation, The Freespireco Project will maintain strict vendor neutrality. The Freespireco Project itself will not distribute medical devices, but empower other organizations to do so. The Freespireco Project may from time to time sell devices not intended to be used as medical devices to humanitarian engineers, researchers, and makers, as it often saves time and money to produce a small manufacturing run of a few tens of machines as opposed to having each party make their own. For example, Public Invention has made two production runs of the VentMon Monitor/Tester which it gave away gratis as a condition of grants it received from the Mozilla Open Software Foundation and Protocol Labs. In the future, Public Invention might sell these devices to researchers and contributors to cover their production costs.

Working with For Profit Firms

The Freespireco Project is a non-profit project hosted by Public Invention, a US 501(c)3 non-profit. However, following the policy of strict vendor neutrality, we welcome any use of The Freespireco Project devices, whether for-profit or not, so long as the letter and spirit of our free culture intention is followed. We hope people make large profits from Freespireco technology, and will encourage this without favoritism.

By using hardware and software designs from The Freespireco Project, a for-profit firm greatly lowers their research, development, and regulatory approval costs.

Community over Code

The Apache Way articulates the principle: “Community over Code”.

The code is easy to see. But in fact having hundreds of volunteers contributing to The Freespireco Project has equivalent benefits. These volunteers are learning and spreading medical knowledge. These volunteers are creating a pool of talent to make medical devices independent of The Freespireco Project. People are learning and integrating knowledge on regulations, medicine, and engineering. The ability to successfully build a respiration ecosystem may transfer to other endeavors.

A Financing Observation

Hardware projects require at least some volunteers to have a modicum of hardware. Writing in the 2020s, these costs have become relatively low, generally measured in thousands of US dollars, but usually not tens of thousands.

Public Invention does not compensate volunteers. However, we have purchased equipment, but durable and consumable, for volunteers. Our experience has been that this has a high return on investment in terms of increased morale and motivation. For whatever reason, many humanitarian engineers seem to value $1000 worth of equipment that they don’t have to reach into their own pocket to pay for at least as highly as $1000 in compensation! Our general plan for the The Freespireco Project is therefore to pay for equipment so that volunteers avoid personal, out-of-pocket expenses. We do not anticipate compensating volunteers directly.


Photo Gallery