Reduced risk of stroke with the help of 3D printing

Details from the example of use

Location Hechingen: This small town on the edge of the Swabian Alb is known for its Medical Valley. Numerous companies and start-ups develop innovative medical technology products here. Since its founding in 2019, Qatna Medical has specialized entirely in the treatment of structural heart disease. This allows people with atrial fibrillation to protect themselves from strokes and avoid lifelong use of blood-thinning medication. Unlike conventional implants, this novel method relies on biological tissue instead of synthetic material. This is intended to improve compatibility within the body.

The vision is that patients treated with the implant will need to take fewer medications, which can improve their quality of life. However, this still needs to be proven after the clinical trial is completed. Plastic parts from a 3D printer also make this possible. 1zu1 has created a compact handle for the implant insertion system, exploiting the full potential of SLS technology. Six chemically smoothed and partially printed components fit together perfectly, are leak-proof, and are easy to clean. Certification according to EN ISO 13485 also facilitates the approval process.

Development engineer Felix Schneider from Qatna Medical and Stefan Rädler, Head of Additive Manufacturing at 1zu1, provide insight into the creation of this flagship project.

3D printing offers many advantages—especially for small production runs, such as in medical technology. What was the deciding factor for Qatna Medical?

Felix Schneider: From a purely geometric and functional point of view, the handle is ideal for 3D printing. During surgery, it comes not into direct contact with the bloodstream. The criticality is therefore quite low. The components must therefore “only” be made of biocompatible material and be sterilizable. Certificates from the supplier, such as EN ISO 13485 certification, are helpful for approval. This reduces bureaucratic effort and saves valuable time. If these requirements are met - and 1zu1 can do that - quality management is satisfied. However, the leap from conventional manufacturing to 3D printing still requires a few good arguments internally.

What would those be?

Felix Schneider: The whole thing has to be practical and safe. Proven processes such as injection molding enjoy a high level of trust. 3D printing still has to earn that trust, and it needs pioneers to do so. I thought: a young start-up and 3D printing are a good fit. 1zu1 has a good reputation in Medical Valley Hechingen. So in 2022, I signed up for the two-day “Additive Manufacturing” workshop in Dornbirn. It was really exciting, the perfect introduction.

Stefan Rädler: Many people still associate 3D printing with fragile prototypes or grainy, rough surfaces. We prove the opposite with stable, smooth, and sterilizable components. Another possible reservation is repeatability. With our machinery, we can produce thousands of pieces with exact and, above all, consistent dimensions and tolerances. 3D printing is absolutely ready for series production – especially for sensitive applications.

What added value did the AM workshop bring to the project?

Felix Schneider: Markus Schrittwieser (note: innovationmanager at 1zu1) took a lot of time to explain the possibilities and limitations of the technology in a very clear way. We then discussed the specific assembly. For example, coloring was quickly ruled out because the effects on biocompatibility are still too little known. I really appreciated the open and honest approach. By this point at the latest, it was clear to me that I wanted to make the handle using 3D printing. It was worth it.

What were the construction requirements?

Felix Schneider: The handle consists of six individual parts, including the two-piece core with the locking mechanism. They need to look good and feel high-quality. After all, medical staff are used to smooth surfaces. From a purely technical point of view, it is important that all six components fit tightly together so that the contact pressure for the catheter tube is correct. We had to go through a few iterations to achieve the necessary tightness. That's where 3D printing came in handy. With this tool-free process, the design can be optimized quickly and cost-effectively. As soon as the change is drawn, it is printed and tested again. This flexibility saved us time and money. An example: At the beginning of 2025, we optimized the design once again. This allowed us to improve dimensional accuracy and shorten the flush channel. This simplifies cleaning before assembly in our clean room.

What other advantages did the technology offer?

Felix Schneider: From the outside, the parts are quite inconspicuous, but behind them lie extremely complex geometries such as internal threads, undercuts, and narrow channels. In addition, there are significant differences in wall thickness. All of this would have been very difficult to achieve using injection molding - and would have involved high tooling costs and complex assembly. 3D printing offers complete geometric design freedom. We have exploited this to the full.

What else can 1zu1 help with?

Stefan Rädler: Our standard is cleanroom quality, as we offer in injection molding. To achieve this, we cooperate with an external partner. They clean all components and return them to us double-packed. With the ISO 13485 certification, which is particularly relevant for medical products, we have taken another important step forward. Qatna Medical also purchases nine injection-molded parts from us. We therefore offer the full plastics package as an efficient hybrid solution. The appropriate process is determined based on the application and requirements of the parts.

What's the next step?

Felix Schneider: With the final design of the insertion system now complete, we are moving on to verification and validation. We will need around 2,000 samples over the coming months for tensile, corrosion, and leak tests. If everything goes smoothly, clinical trials and the approval process will begin thereafter.
 

In conversation: Felix Schneider is a development engineer at Qatna Medical, where he is responsible for all plastic components. At 1zu1, project manager Stefan Rädler ensures the smooth implementation of the 3D-printed parts. Joshua Köb conducted the interview.