FORT DETRICK, Md. -- When a medical device breaks down on a U.S. Army unit deployed to a remote part of the world, the closest repair parts could be thousands of miles away.Even when parts are readily available, the shipping process -- sometimes into hostile environments -- could take days or even weeks, if it's logistically feasible at all.As the Army embraces advanced manufacturing in its modernization strategies, medical logisticians are looking to 3D printing as a potential solution to this challenge."The medical industry is one of the fastest innovators in the defense industrial base, so the AMLC is used to working with industrial partners constantly pushing the state of the art," said Jack Rosarius, director of Medical Maintenance Management Directorate within the U.S. Army Medical Materiel Agency, a direct reporting unit to Army Medical Logistics Command.Specifically for medical devices, 3D printing technology -- also known as additive manufacturing -- may enable the Army to develop repair parts that extend the life cycle of equipment and ensure they are ready for use when and where Soldiers need them.While the technology offers numerous new uses and potential advantages, it also poses regulatory challenges and warrants safety considerations still under review by the U.S. Food and Drug Administration.On Dec. 9, 2019, AMLC hosted a military-specific workshop at Fort Detrick with FDA leaders on the topic to seek guidance on current policies, concept regulations and potential stumbling blocks as it explores manufacturing its own repair parts and other 3D-printed items.Representatives from Army Materiel Command, Air Force and Defense Health Agency also took part in the discussion.'REALLY EXCITED'USAMMA started piloting additive manufacturing in 2015 in partnership with its equipment program managers. Rosarius said a heightened top-down focus from Army senior leadership has only helped to push the 3D printing movement forward."I'm really excited about the opportunities," said USAMMA Commander Col. Timothy D. Walsh, who also serves as deputy commander of AMLC. "It's an exciting time to be a part of Army medicine."The 3D printing process involves building a three-dimensional object using a computer-aided design model by adding material layer by layer, which is why it's called additive manufacturing.The process differs from conventional machining, casting or forging, in which material is removed from a stock item or poured into a mold and shaped to form a product.Through 3D printing, medical devices can be produced using a range of media, including metals, plastics, hydrogels or even biological materials. Most printing systems do this by dividing or slicing a digital design file in two-dimensional layers, then building each layer on top of the previous layer.According to the FDA, medical companies began embracing additive manufacturing to create devices that were previously impossible to make, personalized to the patient or both.'GRAY AREAS'While the technology has unlocked new production possibilities, it also has prompted the FDA to explore conceptual regulations to safeguard patients and institute performance requirements."The FDA is very focused on what the risk is and how to mitigate it" with 3D-printed medical products, said Matthew A. Di Prima, materials engineer for the agency.Heather L. Agler, a senior program manager for the FDA, said the technology has created new "gray areas," specifically when it comes to military production and uses.Patient safety, however, remains the overarching issue under consideration by federal regulators.ARMY'S COMMITMENTDuring the workshop, AMLC officials gave an overview of the Army's Advanced Manufacturing Directive and briefed the FDA on efforts to date.USAMMA has made successful use of 3D printing to produce some obsolete repair parts already, like an impeller for a medical sink or a locking pin for a vaporizer used on an anesthesia machine.Many more are in various stages of development or design."The Advanced Manufacturing Directive demonstrates the Army's commitment to getting this right, so we're positioned for multi-domain operations and large-scale combat operations," Rosarius said. "The medical maintenance community is excited about expanding the ways we can support patient care downrange."Di Prima highlighted different additive manufacturing use-cases, in addition to current agency policy considerations for manufacturers.The group also worked through different Army-specific scenarios to identify possible snags for ongoing or future efforts, as well as several action items for further discussion."We're happy to participate," Agler said. "The military is always thinking forward. It's good to be able to learn ... and very important that we continue to work together to make sure you have the right things available when they are needed."