It is probably safe to say that the advancements in additive manufacturing of medical devices have come at a pace that has outstripped the visions of even the most ardent supporters. 3D printed devices have already been implanted into people’s backs, skulls and jaws.
No less important, however, is developing the quality assurance technology needed to keep pace. In order for the medical device industry to have confidence in the additive manufacturing technology, they need validated techniques to verify the finished parts and improve the process and reliability of the manufacturing chain.
The challenge is to measure the fidelity of a printed device with intricate internal structures to the complex geometry of a CAD model based on patient imaging data. All of which makes acquiring accurate data for quality control challenging.
While medical devices are subject to strict safety requirements, additive manufacturing technology has advanced at a much faster pace than the available standards and quality controls. Regulatory agencies in the US and Europe are taking steps to address the growing need to develop more advanced metrological devices to measure quality.
With funding support from the FDA Office of the Chief Scientist and the FDA Critical Path Initiative, researchers at the Additive Manufacturing of Medical Products (AMMP) Lab at the FDA are studying and developing quality control processes and measurement techniques used to ensure 3D printed devices are produced consistently and performance-measured accurately.
In Europe, a consortium of national metrology institutes has formed Metrology for Additively Manufactured Medical Implants (MetAMMI) to develop and disseminate an integrated, cost effective and internationally competitive measurement infrastructure for Europe. The goal is to establish quality control methods that will facilitate production of high-quality, low-cost customized devices.
At the same time, private metrology laboratories are focusing on the future by refining hardware and software to perform faster, more precise measurements, sometimes on a nanoscale.
Examples include Jenoptik AG (Jena, Germany), which has introduced two new optical technologies, the IPS 100 3D, an internal test sensor that enables automatic inspection of the internal surfaces of cylinder bores with a 360° view of the bore hole, and the IPS F400, which performs optical inspection of surfaces.
Alicona has introduced a real surface metrology technology that allow measurement of the variable surfaces needed in medical implants to allow tissues to optimally grow into the implant. Their Focus-Variation technology combines an optical system with vertical scanning to measure form and texture at up to 10 nanometers in depth.
Carl Zeiss Industrial Metrology is adapting computed tomography CT scanning to 3D printed devices, which allows layer-by-layer measurement with resolutions of slightly over 5 micrometers (5μm or 5 millionths (10-6) of a meter).
Nikon Metrology has developed a two-part laser scanner system capable of collecting object-imaging data at 70,000 points per second, used to measure implant surfaces.
In short, advances in medical 3D printing, particularly for implants, are challenging metrology companies to keep pace with parallel advances in quality assurance technology.
For innovators looking to use 3D printing techniques for their devices, whether you develop your own metrology lab or need to outsource it, Kapstone Medical has the experience and expertise to help you navigate the whole spectrum of challenges you face to achieve the quality assurance you need for regulatory acceptance. For more information, contact us today at (704) 843-7852 or email us directly at firstname.lastname@example.org.
Sources: Advanced Manufacturing.org, A Sharper Focus on Metrology for Medical Manufacturing; 3D Printing Industry, Nikon Metrology Qualfies 3D printed Hip Implants at Ortho Baltic; FDA, Additive Manufacturing of Medical Products; ERA-LEARN 2020 consortium: Metrology for Additvely Manufactured Medical Implants, project home page