Two Polish teams are building respirators to help fight the coronavirus

The popular start of support for healthcare workers heroically fighting the coronavirus pandemic is not weakening. Who can feed the medics, sews masks, protective suits or pays money to buy equipment. Engineers with a considerable contribution are also joining the group of helpers. It’s about respirators that save the lives of COVID-19 patients.

Teams whose aim is to construct devices supporting breathing are set up and undertake strenuous work immediately. Both the simplest last-chance apparatus as well as the more complicated or fully professional one. Work on new, simpler, cheaper and easier to manufacture equipment is also in full swing abroad.

Tesla and Formula 1 – they all make respirators

Really titled teams have joined the fight against COVID-19 in the field of medical equipment – engineers working for Elon Musk at Tesla, the combined forces of Formula 1 specialists from Red Bull and Renault and Mercedes. Their struggles with matter prove that the task is not easy.

Poles began work on the construction of a respirator in March. The first prototype was printed on a 3D printer by the VentilAid team. Its creators have made the project available on the web, pointing out that they do not have the ambition to certify their respirator, as it is to be the last resort for patients who cannot use a professional device. The undoubted advantage of their design is the price, which does not exceed PLN 200, but it results from the resignation from a dozen or so expensive sensors and reliability systems. However, it can be printed and folded in just 24 hours.

Polish respirators – it all starts online

– I came across publications on the design of the respirator on the Internet – says Bartosz Jędrowiak from VentilOn in Łódź – and I started to explore the topic. My wife, who is a doctor, supported me. Later I called a friend who has a metalworking company equipped with precision CNC machines, i.e. numerically controlled machine tools. I met him during my PhD studies and knew that he was able to design and manufacture mechanical components. During the conversation, it turned out that he was also working on a similar idea.

Bartosz Jędrowiak’s colleague, Kamil Słobiński, co-opted another person, a friend of an electronics engineer, Janusz Frydrychowski, and this is how VentilOn was created. In medical matters, the team consulted with specialists in pulmonology and anaesthesiologists from the University Clinical Hospital. WAM, University Clinical Hospital Norbert Barlicki and the Jonscher hospital in Łódź.

– I observed activities based on open source in the network, using 3D printing to create a prototype of a respirator – says Patryk Kadlec, co-founder of VentiHelp in Silesia. – Since I founded a company producing 3D printers a few years ago, I have a lot of contacts left. I called friends on Facebook and we did a starting reaserch. Later, Marek Ciembroniewicz, the co-creator of the famous Polish cardiac surgical robot Robin Heart mc2, contacted me.

Inspirations from Great Britain

– Together, we decided to work on the basis of the guidelines available on the Internet from the British regulator, containing the specification of a device that may be conditionally approved for use in hospitals during the coronavirus pandemic. Such a document is very helpful, because designers do not have to reinvent the wheel, adds Kadlec.

Additional consultations were provided by medical authorities from Cambridge, UK, and doctors from the Silesian Center for Heart Diseases in Zabrze. Dr. Joanna Śliwka, a cardiac surgeon working there, referred the engineers from VentiHelp to an anesthesiologist, Dr. Adam Grzybowski, and thus a specialist support group for the project was created.

The first important decision was to abandon the use of 3D printing.

– The concept work took me a week – says Marek Ciembroniewicz from VentiHelp. – I wanted to eliminate as many errors as possible so as not to come back and correct them later. Since I also manufacture medical devices, I know what they should look like to pass certification.

Although the initial concepts of the VentiHelp team assumed design supported by the rapid prototyping system (rapid construction of objects on the basis of computer models), there will be no elements printed on 3D printers in their respirator. The sockets created in this way will only be installed in the prototype, but already in the production process, the printer will be replaced by an injection molding machine.

The parts printed on the printer do not meet the requirements for medical equipment, incl. they cannot be sterilized.

Also, the team from Lodz decided not to use elements printed on 3D printers. In addition to the fact that such components are difficult to disinfect, the materials are porous, so it is difficult to obtain airtight components. Moreover, 3D prints should not come into contact with pure oxygen due to its high reactivity. In addition, it is impossible to predict how the moving parts will perform during long-term work and whether the particles of rubbed plastic will not get into the lungs of a patient connected to a respirator.

The device should be functional and easy to use

– Ideally, the respirator should be intuitive to use and meet all the requirements for such devices, i.e. in short, it should be a real respirator, not something that replaces it – notes Marek Ciembroniewicz. – With a limited number of medical personnel, there is no time for long training. That is why the interface is crucial, as is the approach to designing it from the user’s point of view. According to British guidelines, the instruction should not last longer than 20 minutes.

Both teams used pre-built parts. Engineers from Łódź made use of the offer of medical stores. They wanted to use as many components as possible certified and already used in similar devices. Bartosz Jędrowiak gives an example of an ambu bag, which is certified to work with a high concentration of pure oxygen, and its primary function is very similar to that of a respirator. They developed the electronics of the device themselves, and more specifically it was the domain of Janusz Frydrychowski. The VentilOn team is sure that this approach will enable the rapid production of respirators and facilitate the passage of the required approvals.

The parts used by VentiHelp are manufactured by Marek Ciembroniewicz, and the electronic and pneumatic components are procured from abroad. Mr. Marek writes the software simultaneously with the construction of the equipment, because, as he says, the logical solution is to connect each subsequent sensor, check if it works and go a step further or correct the design, if necessary. This approach will allow him to create a complete working prototype in a dozen or so days.

What’s the hardest part about building a respirator?

– Currently, medical devices have an almost cosmic look, designed in specialized companies, our housing may not be the most beautiful, but at the moment it is the least important – adds Marek. – The most important thing is that our respirator, which was given the meaningful name HOPE2020 in the process of creation, was a respirator in the full sense of the word. He provided controlled ventilation in the following modes: PC, VC, PRVC and assisted ventilation in the following modes: VS, PS / CPAP, SIMV (pres.control) + PS, SIMV (vol. Control) + PS. The device should be put into production within 2 weeks, and the nice design of the housing would take about 4 months.

The more important things, apart from functionality, are the construction of a stand on wheels, which are necessary in hospital equipment. In addition, you need to keep an eye on the weight, because the respirator should be easily lifted by one person, so it cannot be heavier than 15 – 20 kg.

Power is also a key issue. The device proposed by VentilOn is powered by electricity (12V) and compressed air with a pressure of 5 Atm (adapted to the use of a hospital installation). On the other hand, the prototype from Silesia requires standard medical gases – air and oxygen to function. It also has various power supply options – from the mains (110 – 240VAC / 50Hz / 60Hz), i.e. in any standard, as well as from an ambulance, from its own battery – which allows it to work in conditions of power failure.

Patient safety is paramount

– In the event of any failure or operating errors, the ventilator cannot harm the patient – emphasizes Marek Ciembroniewicz. – You need to carry out the risk analyzes needed for subsequent certification.

This is also emphasized by the engineers from VentilOn: “Our project is not open-source, because it is such an advanced device that its incorrect use by untrained people may endanger the health or life of the patient”.

Their ventilator has a PIPmax pressure control sensor to protect against lung barotrauma. It also has a built-in alarm function for incomplete ventilation, too high PIP pressure and incorrect pressure in the pneumatic system. By using the PEEP valve it is possible to maintain positive airway pressure at the end of exhalation. And the possibility of using heat and moisture exchangers and filters (HMEF) increases the safety and comfort of the patient and protects the medical staff. The device, unlike VentilAid, is based on the use of the SIMV method. It is an advanced method that allows both conscious and unconscious patients to be ventilated. The VentilOn prototype works in automatic mode, so if the patient loses consciousness and his respiratory reflex weakens, he takes complete control of his respiratory function.

Certification, production and price determination of the respirator

VentiHelp plans to test its device at the Experimental Medicine Center in Katowice and probably at the Cardiac Surgery Foundation, with which Marek Ciembroniewicz collaborated during the construction of a family of medical robots. They will take care of certification when they are sure that the device is working flawlessly.

– In England, manufacturers have been exempted from compulsory certification during the pandemic – says Patryk Kadlec – maybe our Minister of Health will do the same … We also have a list of countries that are interested in purchasing this type of equipment, but do not have such restrictive regulations on medical devices.

The VentilOn team is trying to obtain a positive opinion about its respirator from the Provincial Pulmonology Consultant. They also hope for a simplified certification process. After obtaining all the necessary approvals, they are able to produce about 350 respirators per week. At the moment, the price of one has been set at 2. zloty.

In parallel, the team is working on a more autonomous device, equipped with advanced electronics. This ventilator is to be equipped with a battery providing electricity in the event of a power outage. Engineers from Łódź also want to apply for a grant from the Medical University for their project, and they will not despise the support of companies or private individuals interested in cooperation.

VentiHelp has already attracted investors to its project who have declared specific capital. Their idea was to create an inexpensive but fully professional respirator. At the moment, the equipment available on the market, mainly from the USA, costs from 60 to 200 thousand. zlotys. They want to stay in the range of 20-30 thousand. zloty. The prototype is capable of producing 10 pieces a day.

When serial production starts, component costs will go down – says Patryk Kadlec. – Then we might even go down with a price below 20.

Most importantly, Marek Ciembroniewicz and Patryk Kadlec decided to donate some of their respirators to Polish hospitals.

Have a question about the coronavirus? Send them to the following address: [email protected]. You will find a daily updated list of answers HERE: Coronavirus – frequently asked questions and answers.

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