Bringing 3D printed medical models to life

Scott Drikakis, healthcare segment leader - Americas, Stratasys, explores how 3D printing could enable medical device manufacturers to overcome current limitations, improve clinical validation, and change the game of medical device testing.

The use of 3D printing in healthcare is not a new phenomenon. Those who keenly pay attention to technology developments within the sector will be unsurprised to hear of its use. In recent years, Stratasys has worked with customers across the world to improve patient care and communication, accelerate clinical validation and increase innovation. In Europe, hospitals such as CHU Bordeaux and Guy’s and St Thomas’ have utilized the very latest in advanced, multi-material 3D printing to create patient-specific 3D medical models to help plan complex procedures. Equally, customers such as Nidek Technologies have been able to dramatically accelerate clinical trials when incorporating 3D printing into the device testing process.

Despite these incredible advances, 3D printing has had its limitations in terms of organ realism and biomechanical functionality and, to date, has not offered a testing method which covers all problem areas. This means that many medical device manufacturers are still also reliant on traditional testing methods. These predominantly involve the use of human cadavers, animals or virtual modeling. However, as with the current 3D printing solutions available, each of these methods comes with their own distinct limitations. These can range from ethical concerns to lengthy and costly development processes. As a result, medical institutions are continuing to push for technological advancements to overcome such issues. To help make this a realization, it is essential to create a solution that can directly target the specific drawbacks that each of the traditional methods of testing have, as well as overcome the current limitations of 3D printing itself. The recently launched J750 Digital Anatomy 3D printer claims to address all of these issues. Through using advanced new materials and software, this printer can replicate the actual feel, responsiveness and biomechanics of human anatomy.

For all medical device testing, an accurate clinical scenario is a necessity. It is extremely difficult for any of the current methods of testing to create these. Human cadavers are sometimes difficult to obtain and are always highly processed. While medical device manufacturers might sometimes be able to target the correct pathology for testing, the cadaver lacks that ‘live tissue feel’. With animal testing, the correct pathology can only be approximated, and their use can often raise ethical concerns. On the other hand, when customers turn to virtual modeling, any attempt at life-likeness is extremely difficult as touch and depth perception are instantly lost. With 3D printing, although patient-specific scenarios can be recreated, that ‘real-world’ life-likeness has not been possible to date.

Launched in tandem with the new Digital Anatomy 3D printer, a selection of new materials can emulate real-life clinical scenarios better than ever before. Initially, this technology is best suited for cardiac, vascular and orthopedic applications. For example, with the new TissueMatrix material, these models can effectively simulate functions such as tear resistance, cutting resistance, suture pull force and valve regurgitation. With GelMatrix and Agilus materials, aimed at vascular procedures, it can accurately replicate burst pressure, guide wire insertion force, and aneurysm burst pressure. Finally, BoneMatrix can simulate native bone properties for tapping, reaming, spinal alignment and sawing applications. All of these materials are being clinically tested and validated by third parties, and more specific anatomies are expected to be added to this 3D printer’s repertoire every year. Medtronic recently published their validation testing on the Digital Anatomy printer, materials and software.

Although advanced material capabilities are essential, crucially, this new solution includes a software in which specific anatomies, not materials, are chosen. On-demand, users can generate the microstructures required, all the way down to individual bone densities, or patient-specific irregularities. To reproduce such specificities in silicone modeling, or to look for an animal or human cadaver where the pathology is as close as possible to the patient specific requirements, often creates substantial delays in product development cycles. Medical device manufacturers can use Digital Anatomy models to improve design throughout the product life cycle by performing design verification and validation, competitive comparisons and failure analysis. With the Digital Anatomy 3D printer, turnaround times and product development cycles can be reduced by up to 70%.

Of course, the testing of medical devices requires significant financial and logistical investment, too. Human cadavers and animal studies require controlled environments, both of which are expensive to maintain. The Digital Anatomy 3D printer eliminates the need for a controlled environment. The testing of medical devices, and any further clinician training required post commercialisation, can all happen in a no-risk environment. We expect the return on investment to be far shorter than people expect, often under 18 months.

As part of the development and testing of this machine, we’ve worked closely with the Jacob’s Institute (JI), a New York medical innovation center focused on accelerating device development in vascular medicine and Medtronic, one of the world’s largest medical device companies. The JI has regularly turned to 3D printing to recreate patient-specific anatomies and test its devices, but one key issue that previously arose was the inability to replicate live-tissue feel and biomechanical realism. For surgeons such as Dr Addan Siddiqui, chief medical officer at the JI, the biomechanical realism and live-tissue feel of the new Digital Anatomy materials offer the tactile feedback that was not available before. The institute reports unprecedented levels of realism in the 3D models created, which is enabling them to study new devices in actual clinical situations in order to establish their effectiveness, long before they are introduced to patients.

Every day, we are seeing medical institutions improve clinical care with 3D printing. Initially, we expect the Digital Anatomy 3D printer to help our medical device customers advance clinical validation, improve design verification and improve product and field training practices. Academic medical centers and pediatric hospitals can now train future surgeons on complex and rare procedures on demand in whatever environment is readily available to them. We also expect users to continue to advance surgical procedures by utilizing this solution for surgical planning. For us, we are always committed to improving patient care across the world and we know that partnering with our customers is the best way to accomplish this.