Skip to content

Saving Soldiers

Kip Hanson
By Kip Hanson Contributing Editor, SME Media
Nicole-McMinn_768x432.jpg
Nicole McMinn is a biomedical engineer at Walter Reed National Military Medical Center. The 3D-printing lab provides surgical planning models to the hospital staff, simulation models for training purposes, drill and cutting guides for the different procedures, and even make custom implants and prostheses. (All images provided by Walter Reed)

Nicole McMinn never planned to work with service members and their family members as an engineer. She was applying to colleges with the goal of becoming a doctor or nurse. Instead, she went to engineering school and now works as a biomedical engineer with the prestigious Walter Reed National Military Medical Center in Bethesda, Md., where she designs and 3D prints a range of prostheses and other devices at the institution’s 3D Medical Applications Center (3DMAC), work that has a profound impact on patients’ lives.

Smart Manufacturing (SM) recently spoke with McMinn about her work—why it’s important, how she got there, what’s next for her, and whether she still makes a mean cup of coffee (she was a barista during college). Here’s what she shared with us.

SM: What led you to become a biomedical engineer? 

McMinn: I knew in high school that I wanted to go into medicine but wasn’t sure what path to take until I saw a TED talk during my senior year. It was by Dean Kamen, the inventor who designed the Luke prosthetic arm (as well as the Segway scooter and starting the FIRST Robotics Competition) for the U.S. Department of Defense. I thought that was the coolest thing in the world, and since I have always liked math and engineering, and am a little squeamish around blood anyway, it seemed like a perfect fit for me.

SM: Where did you attend school?

McMinn: I’m originally from San Diego and did my undergraduate work at California Polytechnic State University in San Luis Obispo, located between L.A. and San Francisco. I received my bachelor’s in mechanical engineering there before moving to the East Coast, where I started with the FDA [Food and Drug Administration] as a research fellow. I transitioned to be a medical device reviewer at the FDA, which I did for about four years before coming to Walter Reed. During that time, I completed my master’s degree in mechanical engineering at Johns Hopkins University.

femur.jpg
A femur model printed at Walter Reed National Military Medical Center’s 3D-printing lab.

SM: You’ve lived on both the East Coast and the West. Which one’s better?

McMinn: Oh, that’s a tough one. I love the ocean and was fortunate to be less than half an hour’s drive from the beach growing up. I don’t get that in Bethesda, but I really enjoy the area and have made some wonderful friends. So, my answer is that they’re definitely different, but I like them both equally well.

SM: So, your first job was as a medical device reviewer with the FDA? It sounds a little boring, to be honest.

McMinn: Well, there was a fair amount of paperwork, but it was pretty interesting, actually. Most of what I did there was review orthopedic devices from medical device manufacturers before they went to market. The FDA evaluates medical devices for safety and effectiveness and then gives the company clearance or approval if their device complies with medical device regulations. So, I looked at a lot of total joint replacements—hips, knees, shoulders and smaller devices like fingers and toes. As a lead reviewer, I was responsible for reviewing the application, which included test reports that evaluated performance of the device through mechanical testing and clinical testing, biocompatibility concerns, sterilization, labeling of the device, and so on. It was a great first job, and I enjoyed the opportunity.

SM: Tell us about the QL+ Navy SEAL Prosthetic Device.

McMinn: That was my senior project at Cal Poly. Three team members and I spent a year building a prosthetic leg for a Navy SEAL who wanted to compete in a triathlon but needed a prosthetic that would allow him to run, walk and swim. We did pretty well. I don’t think they ever actually used it <she laughs>, but it was a nice prototype. I learned to sew and spent a lot of time modifying a device like one of those Chinese finger traps we played with as kids, which was supposed to help keep the prosthetic on the amputee’s residual limb during the triathlon. We also modified the prosthetic foot with set screws and fabric so he could use the same prosthetic foot as a fin for swimming or for the different terrains. It was a lot of fun.

skull-model.jpg
A skull model printed at Walter Reed National Military Medical Center’s 3D-printing lab.

SM: You’ve been at Walter Reed Hospital’s 3D printing lab for a little over three years now, what do you and your colleagues do there?

McMinn: There’s a nice video on the Walter Reed website that shows the whole facility, but, as the name suggests, we are a medical 3D-printing facility. We have about a dozen machines and seven staff members, and print both metal and plastic. I’m the biomedical engineer, and we also have a director of services, a quality engineer, a dental technician, two engineering techs who are responsible for the segmentation and modeling of the CT and MRI images, and a facility administrator. We provide surgical planning models to the hospital staff, simulation models for training purposes, surgical guides and even make custom implants and prostheses.

SM: Do you actually operate the printers, or is it all design work?

McMinn: We all get to do a little bit of everything, which I love. Yes, it starts with the initial design or segmentation of CT and MRI scans, but carries all the way through to the printing, post-processing, and delivery to medical providers here at Walter Reed and throughout the Department of Defense. Whatever they need for improved patient care, we work on, assuming it’s within our capabilities. Everyone gets their hands dirty here, even our administrator.

SM: You mentioned 3D printing of metal parts. This is not only a big financial investment but requires secondary machining for support removal and finishing of critical surfaces. What kind of printers do you use? And does that mean you’re also a machinist?

McMinn: We have two powder-bed-fusion printers; we utilize an electron beam melting process for our titanium and a laser melting process for our cobalt chrome. To my knowledge, we’re one of the only hospitals in the U.S. with these capabilities. Much of what comes out of those printers is used in the dental space, but we also produce implants for inside the human body. As for me being a machinist, we generally try to design parts so that they don’t need an abundant amount of post-processing, so it’s mostly a lot of sanding and deburring—pretty basic stuff machining wise.

SM: Why would a hospital take on metal 3D printing when there are so many service bureaus out there that specialize in it?

McMinn: The decision to bring metal 3D printing in-house was made before I started, but my understanding is that Walter Reed invested in this technology due to injuries seen in the past several overseas conflicts. The people managing the lab at that time felt it important to have direct interaction with the providers during the design process and fast turnaround that comes with owning your own equipment.

SM: Taking that one step further, are the prosthetics used by military members any different than those of civilian amputees?

McMinn: I believe the military has worked with some of the prosthetics companies to advance their prosthetics limbs, however, at 3D MAC our focus has been end-limb attachments and devices for specialty activities, not the prosthetic as a whole. I’ve noticed that many of those who’ve served in the armed forces want to remain physically active, whether that’s lifting weights or playing beach volleyball. As a result, we design and print a lot of attachments and other adaptations to help them perform these activities.

But we also try to make their post-injury life as easy as possible—for instance, our director of services designed and built some devices that we call “shorty feet.” These look like little paddles that fit on the end of the prosthetic attachment, so that a bilateral amputee doesn’t have to put on their full prosthetic if they need to get up and move around the house quickly. Devices like this make it easier for them to have a more normal life.

SM: It sounds very rewarding. What’s next for you?

McMinn: We’re currently setting up a quality management system at 3D MAC and our quality engineer and I, along with our director of services, are leading that effort by writing the documents. Our ultimate goal is to submit a 510(k) to the FDA for some of our medical devices, which we’re expecting to submit sometime next year. It involves a lot of documentation but will give us better quality control and traceability of the devices we make.

It’s an exciting time to be involved with medical 3D printing. I’ve only been at it for a few years but have noticed that it’s really starting to take off with hospitals and other healthcare providers. I know that larger organizations like the Mayo Clinic and Rady Children’s Hospital-San Diego are doing a lot of cool stuff, yet even at small hospitals, there’s often at least one engineer or practitioner who’s exploring how AM can be used to help patients.

It’s also a very collaborative environment. Because we’re doing this to help our patients, there’s a great deal of knowledge sharing all around. It’s nice to see, and I’m very glad to be a part of it. It’s my dream job.

Always Stay Informed

Receive the latest manufacturing news and technical information by subscribing to our monthly and quarterly magazines, weekly and monthly eNewsletters, and podcast channel.