With this application, the part was split up automatically into 2D layers, and those cross sections were sent to the 3D printer, where a laser beam melted successive thin layers of titanium powder, which fused together to form the part. This process was repeated with each cross-section melted to the previous layer, and it took 33 layers to build just 1mm of height. Once the part was 3D printed, the part was treated with a bioceramic coating to make it look and feel more like a human bone.
LayerWise believes this is just the tip of the iceberg in terms of how additive manufacturing (AM) can be applied to advanced medical implant design. "AM's freedom of shape allows the most complex freeform geometries to be produced as a single part prior to surgery," said Dr. Peter Mercelis, managing director of LayerWise, in a press release. "Patient-specific implants can potentially be applied on a much wider scale than transplantation of human bone structures and soft tissues. The use of such implants yield excellent form and function, speeds up surgery and patient recovery, and reduces the risk for medical complications."
Prosthetics seems to be the next budding market with huge potential for 3D printing .Custom designs, uniquely adaptable to any particular patient anatomy, and the ability to fabricate these custom parts literally overnight, is a futuristic 21st century reality. To take it a step further, developing bio-materials as the next-generation polymer replacements, is a fantastic direction for the industry.
From a design engineers' perspective, this is an exciting field of the "front-end" of design opportunities.But what about the "back-end" --- meaning accelerated life testing of the applied designs-?
What kind of evaluations have been performed by the industry, or by LayerWise; such as materiel integrity over time and extended use (chewing as life-cycling), and especially the physiological compatibility of the foreign material within a human body? Certainly nothing insurmountable, but also this is clearly a requirement in order to claim a 100% design solution.
You raise two good points, Jim. I would hope that lifecycle testing is part of the early-stage evaluation of both the materials and the design on this jaw prosthesis as well as any other 3D printed custom implant. I know there was an added step in the printing process to make the material more "human-like" in terms of look and feel, but I don't know that it necessarily had anything to do with extended use testing. On the other hand, doctors have been using foreign materials as implants in patients for years, particularly on the orthopedics side. I would imagine the same testing/prove out process that exists there is applied to these new 3D printing material advances.
@JimT: Beth has a good point that foreign materials have been used in prosthetics for a long time.Specifically, titanium screws in joints seem to be quite common.I would not expect that each and every specific design would need to tested.Also, life testing in prosthetic replacements shows that many of them are not permanent.Artificial hips and knees will not last forever.I sometimes hear numbers like ten to fifteen years.In this case the patient is 83 years old.I expect that life testing is not a big issue.
Thanks, Beth, for covering this. Implanting devices has been going on for nearly 50 years. FDA regulations regarding biocompatible materials, including implantable ones (vs those used on the skin's surface), are at least in part modifications of ISO standards, such as ISO 10993, "Biological Evaluation of Medical Devices," which is divided into 20 different parts. The handiest brief list of 10993's 20 different parts and what they govern seems to be at Wikipedia, not at ISO or FDA's sites:
Anyway, the different types of implants being done are pretty broad, such as knees, hips, monitors, and various dental implants. The most common implantable materials are titanium and various polymers. I think what's so cool about this is the fact that it's being done with AM.
Cool article, Beth. Why was the jaw chosen as the beginning of this technology? Is it because there was greater need with that part of the body? Knee and hip replacements seem pretty advanced. Are there other parts of the body coming soon?
I expected to read a story about how surgeons built a prototype mandible for use in understanding the fit of the actual jaw bone. I did not expect to read that they built the ACTUAL mandible with a 3D printer. For whatever reason, I assumed that a "bone" from a 3D printer would be biologically incompatible for use in the patient's body. This is an incredible example of how far 3D printing has come.
To me it's neat to think of the ability to adjust the standard jaw bone to make it larger or smaller and then customize to the shape of the individual patients shape. Combine this with the ability to scan the patients face or features before the change and the possibilities are staggering.
@Chuck: It is pretty crazy that this wasn't an effort for building a prototype, but rather for the real McCoy. My understanding is that AM's ability to customize the mandible for the specific patient's fit is what make it such a compelling option for this particular application. And you're right, Chuck. It does show just how far 3D printing has come.
@Ann: Thanks for sharing those great links and resources. Definitely helpful for any one wanting to drill down more into the standards surrounding implants and materials choices.
When researching this, I found several articles about the future of 3D printing to "print" human organs and body parts, using organic materials to "grow" body parts like blood vessels and other organs. Obviously, that's just in the research stage and likely still years, if not decades, away, but it still a very promising technology for advancing medical care far into the future.
@Beth. Medical advances look like they will the space program of the coming decades. I thinjk the oh-wow advances will be in health. That will put enormous pressure on state-funded medicine, and it will probably extend both quality of life and life expectancy.
Producing high-quality end-production metal parts with additive manufacturing for applications like aerospace and medical requires very tightly controlled processes and materials. New standards and guidelines for machines and processes, materials, and printed parts are underway from bodies such as ASTM International.
Engineers at the University of San Diego’s Jacobs School of Engineering have designed biobatteries on commercial tattoo paper, with an anode and cathode screen-printed on and modified to harvest energy from lactate in a person’s sweat.
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