100-Percent Measurements Thanks to Automation

Bone implants represent a Swiss success story spanning more than 60 years. “In Switzerland, surgical treatment of bone fractures was advanced and standards were set that are recognized worldwide. Working with the country’s precision manufacturing industry, implant designs were developed that are still relevant today,” says Lorenzo Zoccoletti, CEO of Genostis, based in Burgdorf in the canton of Bern. “We are continuing this tradition with a generic bone implant system produced 100% in Switzerland to the maximum dimension of quality.”

In this context, “generic” means that Genostis implants – —inspired by generic drugs in the pharmaceutical industry – —are based on well-known designs that are now patent-free. Thanks to the generic principle, research and development costs are negligible. “Our plates and screws are based on designs that have been proven over decades. Through an in-house reengineering process, we optimize them to meet today’s requirements for patient-friendly use and efficient manufacturing,” explains Zoccoletti. The president points out that the prices for his generic implants are significantly lower than those of other well-known suppliers, without having to compromise on quality. “This allows us to ensure the highest possible product safety and compete with the leading suppliers,” says Zoccoletti.
Since the largest cost component arises during production, those in charge there focus on achieving very high efficiency. “We have very high labor costs here in Switzerland,” says Carmelo Blandini, COO of Genostis. “That’s why highly automated production processes and the intelligent use of innovative production equipment are crucial to our success.”
A core element of production is metrology. “All of our implants must meet the strict regulatory requirements for medical devices, including the applicable EU Medical Device Regulation (MDR) 2017/745,” explains Zoccoletti. “The CE mark is a prerequisite for marketing an implant in the EU. To obtain it, we must provide various forms of evidence, which are tested by a certification body.”
In addition to extensive validation measures, certain measurement tasks are unavoidable, such as the initial sample inspection of individual products. In addition, measurements close to production are required, which Genostis has consistently automated and integrated into production. “For our concept, computed tomography seemed to us to be the most suitable measurement technology,” explains Blandini. He ruled out conventional tactile 3D coordinate metrology for various reasons: The time and cost required for the necessary fixtures and measurements are enormous, and the test specimens would have to be positioned manually. An industrial CT machine, on the other hand, offers much better conditions for achieving the desired high level of automation.
The Genostis management team opted for the Tomo Scope XS Plus 160 from Werth Messtechnik. “We were familiar with Werth as a renowned provider of metrology solutions that has long offered coordinate measuring systems for industrial computed tomography,” said Blandini. The selected Tomo Scope XS Plus 160 meets all the basic requirements for reliable and quick measurement of Genostis implants. It enables the scanning of small and medium-sized workpieces up to approximately 300 mm in diameter and 450 mm in length. A key component is the transmission tube in a monoblock design, which enables a small focal spot even at high tube power, allowing for fast measurements with high resolution.

Tube voltage allows for the measurement of titanium plates
The machine’s maximum tube voltage is 160 kV. This enables the measurement of workpieces with greater radiographic lengths and denser materials. “Since we need to capture the geometries of titanium plates and screws, this was an important deciding factor,” explains Blandini. However, he also points out that the required cycle time for production monitoring posed a challenge, as short capture times for the workpieces are essential. “We had to invest some time before we gained the necessary experience with the CT sensor.” This is because Genostis wanted, for example, to scan the titanium workpieces in multiple orientations. “Since the measuring objects influence each other during the measurement process, which can lead to image errors—so-called artifacts—we conducted numerous tests regarding the number of parts and their positioning relative to one another in order to achieve good results,” explains Dusan Mirkovic, Head of Production & Automation. “The CT specialists at Werth actively supported us with their expertise, enabling us to gain a great deal of know-how and ultimately develop measurement strategies tailored precisely to our products.”

Scan time per titanium workpiece ranges from 2 to 5 minutes
Genostis has succeeded in reducing scan times from an average of about 20 minutes to 2 to 5 minutes per titanium workpiece. “These values depend on the products, their size, the required resolution, and the sizes to be captured,” explains the production manager. “On average, ten to twelve critical geometrical characteristics need to be captured during a measurement. As a measurement result, the Tomo Scope XS Plus 160 provides the complete three-dimensional workpiece volume. The user can set the resolution to any value (up to 60 billion voxels). “The 3D nominal-actual comparison is excellent,” praises Mirkovic. “To do this, we import the 3D CAD model and compare it with the measured point cloud in STL format. Based on the color-coded deviation plot, you can very quickly determine whether the workpiece is within tolerance. If we then determine a few critical geometrical characteristics—whose values are also automatically recorded in the measurement report—we can approve the medical device for use within seconds.” He adds another important factor: “For our work in metrology, it’s crucial that the measurement results are reliable and have traceability. Werth Messtechnik guarantees this through standard-compliant calibration, including a DAKKS certificate.”
The Tomo Scope XS Plus 160 features additional characteristics that are valuable for use in production. For example, the monoblock design of the X-ray tube, voltage generator, and vacuum system ensures long maintenance intervals and a theoretically unlimited service life. This minimizes downtime and operating costs. A key strength of all Werth CT machines is that the reconstruction of the workpiece volume occurs in real time, parallel to image acquisition. This enables fast, in-process measurements.
Programming, control, and evaluation of the entire measuring process take place in the WinWerth® measurement software. Genostis uses it not only on the TomoScope itself but also at two additional workstations dedicated to programming and evaluation. “This way, we never tie up the measuring machine with other tasks,” says Mirkovic.

Measurement cell with a robot and a rack system with 135 positions
Thanks to its compact design, the TomoScope XS Plus requires very little space, and its excellent accessibility makes it highly suitable for automation. To this end, Genostis installed a measurement cell featuring a robot and a shelving system with 135 storage locations. The interface between the coordinate measuring machine and robot controllers ensures that the coordinate measuring machine’s door opens when the robot needs to load or unload the fixtures during feeding. The corresponding measurement programs, created by Mirkovic, are loaded accordingly.
Currently, Genostis primarily performs measurement tasks on plates and screws. According to the expansion of production, the Tomo Scope XS Plus 160 will also be used increasingly for validation and initial sample inspection. Blandini sums it up: “As of today, we are very satisfied with our CT coordinate measuring system. The technology is excellent, and the application has now been tailored to our products. We obtain accurate measurement results with high reproducibility. Simple fixtures are sufficient, and the measurements are relatively fast thanks to multi-point clamping and automation in the process.”