One of the most interesting applications of 3D printing in the face of the Corona crisis is undoubtedly the possibility of producing accessories for ventilators quickly and inexpensively. However, there are a few pitfalls to be aware of, as we would like to illustrate using a concrete example.
It was Friday, March 13, 2020, when Enrico Castro-Camus, a Mexican guest researcher at the Philipps University of Marburg, suggested to his boss Martin Koch that improvised ventilators to develop and publish their plans. Their components should then be easy to produce on a 3D printer. After all, things were developing so dramatically in those days that it was feared that the available ventilators would soon no longer be sufficient for all patients. In any case, Koch agreed and on the following Monday (March 16) put together a team for this new task. And so in those rooms where everything normally revolves around semiconductor photonics, physicists, mechanical engineers and computer scientists developed their own concepts for ventilators together with medical professionals.
Rapid success thanks to sleep medicine
In fact, within just a few days, the Marburg team was able to develop a prototype that regulates the continuous flow of air to match the inhalation and exhalation of a potential patient. Respiratory rate and air pressure can be adjusted. An alarm also sounds if the device fails.
The key clue had come from a colleague at the Sleep Medicine Center who had suggested so-called CPAP machines equipped with an additional device. These provide patients with a continuous flow of air if they suffer from breathing disorders during sleep. These devices are particularly widespread in clinics and sleep laboratories, so they could promise a good basis for rapid spread.
Not a substitute for a professional machine
However: The Marburg prototype can by no means keep up with professional equipment. “If someone comes to the clinic with blue lips, they have to be connected to a professional device,” says Martin Koch. Only after a few days, should the patient have recovered during this time, could this extension take over and the high-tech machine could be made available to the next seriously ill patient.
In fact, this concept was immediately welcomed by senior physicians and intensive care physicians. “Before I have no other option at all and a patient dies, I would of course use your devices,” it said.
Weak point in the approval process
However, the Marburg researchers had not thought of one crucial point. “Initially, we didn’t even think that we would build a medical device that needed an approval process,” says Martin Koch in retrospect.
So the developers received from the responsible Federal Office for Drugs and Medical Devices (BfArM) the provisional information that the devices are not practical. These would not provide the necessary performance that is necessary for the complex ventilation of Covid 19 patients. “In addition, there are hygiene concerns, which means that a hazard to the staff using the product cannot be ruled out.” The Marburg team replied at the beginning of April that at least the hygiene concerns could be solved technically.
Nevertheless, Martin Koch finally decided not to put the construction plans on the Internet for the time being. The risk is too great that users could incorrectly recreate them or use them without medical supervision. After all, the latter could endanger human lives.
Cooperation with optics company
After all, the Marburg team was looking for cooperation with one optics company, with the help of which this development could still partially be implemented. This company finally took over the development of a design for an extension of that machine and is now itself conducting the negotiations with the BfArM in terms of approval.