When the diving mask becomes a breathing mask

For days now, the 3D printers have been running at full speed in so-called maker spaces such as the xHain in Berlin-Friedrichshain or the understanding station in Fürstenberg in Brandenburg. You are about to produce 2000 facial shields for hospital staff. A holder for thick, transparent PET film is made on the 3D printer, the shield can then be put on and protects the entire face.

Platforms want 3D – Network printers and clinics

There are similar projects in many other places. In order to better coordinate the activities of the 3D printing activists and connect them to hospitals, a team from Lübeck is working on a networking platform. The project, called Print4Life, was created as part of the German government's WirvsVirus hackathon. It is one of the 20 projects that were selected and are now funded further.

Siemens recently opened its 3D printing network. Above all, industrial companies can offer their printing capacities via the platform, for example to manufacture spare parts for medical devices that are currently not available. Since then, more than 70 new providers have been added, says a spokesman. The Fraunhofer Institute for Reliability and Microintegration (IZM) is also working on a similar project. “Hopefully there will be an exchange between the platforms,” ​​says Stefan Kamlage, board member of the 3D Printing Association.

Charité tests protective masks from 3D printers

Various member companies, together with the 3D Lab of the TU Berlin and the Fraunhofer Institute for Applied Polymer Research IAP in Potsdam, have also started an initiative to develop methods of additive Use manufacturing in the fight against the corona crisis. The first prototypes of protective masks have just been handed over to the Charité for testing. The silicone masks enclose the mouth and nose. “They should be as comfortable as possible so that they can be worn all day and have replaceable filters,” says Kamlage. The models and templates will then also be made available to partners in other regions.

Mit 3D-Druckern und Folie werden vielerorts Gesichtsschutzschilde gebaut.

Face shields are built in many places with 3D printers and foils. Photo: Roosevelt Cassio / Reuters

But the activities of researchers and entrepreneurs go far beyond protective masks: they also face the worldwide shortage of ventilators them with unconventional solutions.

Tens of thousands of snorkel masks for conversion

In Italy, the Isinnova company from Brescia has already manufactured missing valves for ventilators on the 3D printer for the local hospital. Then the company took up an idea from the former chief physician of the Gardone Valtrompia Renato Favero hospital: since masks for certain ventilators were missing, he had proposed to convert snorkeling masks from the sports discounter Decathlon. The Easybreath models seemed suitable for this because they enclose the face. Isinnova developed valves for retrofitting and puts the information online.

The civil defense in Brescia initially 500 Models ordered, now Decathlon has in Italy 10. 000 provided such diving masks. The Oldrati Group manufactures an injection mold for massive industrial production of the required valves. According to a report by the Corriere della Sera, the modified masks are now in real use in hospitals in Chiari, Parma, Lovere and Esine. In addition to ventilation, they are also used to protect personnel.

German contacts wanted

In Turkey, an Italian entrepreneur is also converting 300 to the snorkel masks. The company holds 30 in France and Spain. 000 Masks for hospitals ready and has stopped selling them. In Germany, it was limited to a maximum of five masks, “in order to prevent commercial buyers from making a profit from the situation,” as a spokeswoman said.

Auch in Tunesien setzen Ärzte auf Taucherbrillen, die zu zu einer Atemschutzmasken umgebaut werden.

Also in Tunisia, doctors rely on diving goggles, which are converted into breathing masks. Photo: Khaled Nasraoui / dpa

Decathlon has also received many inquiries and large orders in Germany and wants to support research centers, hospitals and authorities. The company contacted several state health offices earlier this week to find a contact person for central organization and subsequent distribution of the masks. “Unfortunately, it is not easy to find the right contact person at the state level,” says the spokeswoman.

Marburg scientists are waiting for approval

In Germany, various research groups are working on their own solutions to find Covid 19 – to help patients. The “Breathing Project” by physicists from the University of Marburg is already very far. “We are finished with the development,” says Martin Koch. The professor is actually a specialist in semiconductor photography. But in the crisis he and a team picked up an idea from the university's sleep medicine center. There is a lot of work with so-called CPAP devices (Continuous Positive Airway Pressure), which are used for breathing disorders such as sleep apnea. It is estimated that in two million German households there are these “snoring masks” with which breathing interruptions are prevented. While the CPAP devices normally generate constant air pressure, the Marburgers modified them with valves that open and close in such a way that they can also be used for ventilation. Several doctors were involved in the development and said they would use the devices if there were no other options. “Of course it is not as powerful as professional ventilators,” says Koch. But it could be an option for patients who have already recovered somewhat. “The professional devices are then released for harder cases,” says Koch. Production could also start directly with the Schneider company. “Unfortunately, we lack approval,” says Koch. The team is in contact with the appropriate departments and hopes for a quick procedure.

Mechanize ventilation balloons

This also applies to a second approach to make ventilation aids even faster and cheaper. Ventilation balloons are used. The so-called ambu-bags are pressed manually by emergency doctors to provide patients with oxygen. The Marburg-based company has developed a design with a motor that mechanically compresses the resuscitator regularly. “The wooden frame may look unprofessional, but we deliberately used simple materials that are also available in Africa,” says Koch. Because this solution is primarily intended for developing countries, where there are no other alternatives. “We would like to publish the construction plans on the Internet, but then we would make ourselves punishable,” says Koch. After all, there would be no approval as a medical device for the design. In this respect, the YouTube videos should currently serve as inspiration – for potential users and other inventors.

Worldwide work on open source solutions

Various groups around the world are working on similar approaches: The MIT E-Vent project in Boston, Oxvent at Oxford University, the Irish Opensource ventilator project or a Spanish consortium at the Leitat technology center . In this country, the DIY ventilator project is currently examining these and other approaches. “Worldwide there are definitely 100 to 150 designs, ”says Jan Borchers, Professor of Media Informatics at RWTH Aachen University and founder of the Fablab there. The revolution in digital manufacturing may have come just in time in the crisis. Today developers in Aachen could put new plans online and corresponding components could be replicated with high precision on any 3D printer in the world.

Also in Aachen, four teams are developing prototypes for mechanized ventilation balloons in various application scenarios in the Coresponse project. They are also primarily intended for regions such as Africa or India. The strength of the structures is currently being checked. “We have not yet carried out any tests here that go beyond a few hours,” says Jonas Gesenhues. However, this is a critical issue, especially in 3D printing. “It may even turn out that 3D printing could be unsuitable for this,” says Gesenhues. At the moment he cannot imagine tests on humans, the solution is far from being reliable enough. And maybe nothing will change in the future. After all, other groups are still developing and progress could overtake Aacheners. “We believe that there will soon be sufficiently high-quality ventilators and such a simple concept as we are researching will be obsolete,” says Gesenhues.