Troy Nickel joined ViVitro Labs in June 2023 as our new director of product development. He holds a Master of Science in mechanical engineering from the University of Minnesota. Shortly after graduating, Troy joined EnduraTEC System Corporation, which specialized in the development of medical device durability testers. The ElectroForce group from EnduraTEC was acquired twice. The first time in 2004 by Bose, and the second time in 2015 by TA Instruments. Troy stayed and grew with the various organizations holding several director positions in R&D, business development, product management and more.
Karim Mouneimne, President of ViVitro Labs, welcomes and interviews Troy in a wide ranging discussion on medical device testing.
Karim Mouneimne Troy, you have an impressive track record in the medical device industry and many of our customers have used the test systems you have designed. The stent graft tester has a long track record in stent fatigue testing. What criteria did you apply and what challenges did you face while engineering the most used stent graft tester in the world?
Troy Nickel The stent graft tester, or SGT as a lot of people call it, has evolved over time. I worked on it with lots of other talented people and I think the biggest challenge is shifting from focusing on the core purpose of the machine of doing a radial fatigue test quickly and accurately. That’s sort of the place you start. You’ve got raw motors and controllers and software. And as we get better and better at it, it goes beyond just the basic function and more about how stable it is. How easy is it to use and produce stable results for a long time?
Obviously, we have very long-term tests. These are broad challenges for cardiovascular medical devices. The tests are weeks and months long. So, the broader challenge is how do you bring all that power to something that is usable by not just the most advanced users, but for more people? And how do you enable them to get results that are stable over a long time, that in the end you can trust?
Trustworthiness is so important to get right. It’s easy to do it rough and crude, but then to polish it, in my experience, took three generations to feel like, “oh, we’re really getting this right and stable”. The first generations you had to really be careful using them. They were more sensitive and user variable. And the challenge is how do you bring that power and stability to more people.
Karim Mouneimne I agree. I was one of the early users. I remember talking to you a lot on the phone. I think the tester must be able to be used by very advanced users, experienced users, but also young engineers that don’t have the background. It must be reliable to provide that data. In your mind, what is reliability in fatigue testing? What is the important aspect of reliability in fatigue testing?
Troy Nickel Ideally, it’s stable loading over a long time. And even more important, if it’s not stable, it’s at least reporting what it is. So if you’re attempting to produce a given amount of force or pressure or strain and you ask it to do that, ideally you’re doing exactly that the whole time. But if it’s a little bit low sometimes or it’s a little bit high sometimes, it’s really important for the instrument to measure that properly and report that as it is.
Otherwise, it looks great on paper, but if in the end your device didn’t experience the loading that you report, under loading or overloading, that’s a failure on the instrument and the methodology to use it. I think the premium is on the reliability of the measurement, the trustworthiness of that measurement. And then the second aspect is how stable the instrument is in doing exactly what you want over a very long time.
Karim Mouneimne Let’s switch gears a little bit. EnduraTec is very famous, at least for my generation. What is the biggest contribution EnduraTec System and Bose have made to the medical device industry and why?
Troy Nickel The EnduraTec origination of stent testers, and some of the early electromagnetic powered instruments from Bose, (that became ElectroForce and eventually TA ElectroForce). Over almost three decades now, I think the products, the stent graft tester and the multi specimen fatigue instruments have really enabled a lot of really good progress in medical device time to market, reliability of the package that our customers are providing to the FDA. To again provide trustworthy results. I think those two products have advanced the reliability of test success results. “Yes. My instrument performed 400 million cycles. It did not fail. It had reliable loading along the way”.
And then as we got better at driving harder, enabling multi specimen fatigue, understanding coupon samples, wire samples, it became empowering for fatigue to fracture and breaking devices at much higher loads, much faster. Which is enabling more insights and more design optimization quicker, another value of time to market.
So, it’s not just about 400 million as fast and stable as we can (which was how we started), it became “how do you drive even farther and at high rates to fail quickly, learn quickly and then iterate designs quickly?”. And if I look at all the customers that we’ve delivered products to in over almost 30 years, there are a lot of devices that are better because of our ability to provide feedback quicker and in a reliable way.
Karim Mouneimne I think one of the challenges of the fatigue testing is the duration of the test. And that sometimes gets in the way of the device development process. So, you’re right- do it quicker, better, and as reliably as possible – it is indeed a great challenge. EnduraTEC, and maybe Bose, did not solve all the challenges the medical device industry faces. In your eyes, what are the current and future challenges in our medical device testing field?
Troy Nickel How do you bring device modeling and FEA models together with testing and making that an efficient and reinforcing process to provide insights reliably and quickly? I think that’s always the challenge. I think the temptation is to use FEA more and more, which is a good temptation. There’s a lot of power there, CFD, FEA. And then what’s the right balance of actual physical validation of those models and then physical validation of the resulting products?
I think trying to get that right in terms of getting a lot of samples tested, but those things take a lot of time. How quickly we can move models and just balance the right amount. I think the challenge to regulatory agencies as well is that as the ante is upped, the capability is even greater today than it was, it’s tempting to require more and more and more because it’s now doable. What’s the right balance of the right amount to do?
Karim Mouneimne I think what you mean by balance is how in vitro testing can be used to validate computational models and vice versa. Right?
Troy Nickel Yes. You can advance them both. They both have advanced substantially and both are required. So yes, they’re both powerful parts of doing the design properly and then passing regulation as well.
Karim Mouneimne What lessons from fatigue device fatigue tests that you’ve learned can be applied to new equipment design and performance?
Troy Nickel In my experience, certainly reliability, appreciating time is money, time to market, all these things we do to run things fast and things reliably can be applied to new equipment design and performance. But coming back to what I said originally, I also think about making it usable and making it realizable. Allowing for more users at more skill levels to be able to run a good test is important. And part of that is how do you qualify the equipment when you get it? How do we make that easier? And then how do you maintain it as it goes? How do you make that easier?
Whether it’s software usability or physical usability, if you don’t make it so that only the most advanced, most experienced users can run tests. Because most experience and most advanced means they probably failed a bunch of times along the way. So how do you reduce the number of failures in order to run good tests? By delivering products that are easy to use. I think that’s my biggest lesson learned. It’s not just about the core power. It’s not just about the core performance. It’s also about how you make that easy.
Karim Mouneimne Some things you’re saying would echo in the world of customers trying to custom design their own equipment, jury-rigged homemade devices. And sometimes the result is usable by only one specific engineer. That person leaves, you lose a lot of things. It’s not scalable, sometimes not validated, and it’s complicated.
Troy Nickel I’ve seen so much of that in my career. I think that temptation is probably worse in academics due to lower funding sources and graduate students that you can apply to designing things. It’s tempting to make home-built instruments. But I think in industry and medical devices it is the same. 20 years ago, we saw a lot of “we’re going to make that in-house”. And we’d have a conversation. “Okay, fine. You know, you’re capable engineers, that’s fine, no problem”.
I started to really appreciate our value as test equipment designers and manufacturers. Let device engineers do the engineering of the device and not of the laboratory instruments. And companies like ours could focus on designing instruments that are used by many organizations so their engineers can do their engineering work. And I think that’s probably what they want to do anyway. They don’t want to design controllers for motors on a laboratory custom solution.
The challenge of how you get that custom made thing characterized well enough to make its results trustworthy by regulatory agencies. That hurdle has been stumbled over so many times. You have a machine that could work great, but you’ve got to now do a whole big project to prove that it works great, even though you know it works.
A lot of engineers come back and say, “okay, it’s better to just let you guys do this work. You guys are good at it. You’re the people who can focus on it and the regulatory agencies know those instruments.” The more popular the test equipment is, the more familiar it is, just snowballs to make more value that we can deliver to medical device companies.
Karim Mouneimne I certainly agree. There’s a whole process that lives around in equipment. It’s the procedure, the methods, the validation, the qualification. It’s not just the equipment. What’s your first impression of the new heart valve durability tester that ViVitro has designed? How does it compare to other systems? I’m not asking you to basically give us a competitive argument. But, generally, based on your broad experience what’s your impression?
Troy Nickel It’s exciting to see a fresh perspective on the solution. That’s probably the biggest thing. I understand the test and the general technology so well. But the innovation that’s at the heart of the AWT is exciting for me. Just the general breaking apart the control of open area from back pressure or differential pressure control and driving those distinctly with quite different mechanisms allows us to do more advanced control. And the ability to control pressure that’s quite isolated, not perfectly isolated, but quite isolated from the opening of valves. I think there’s a lot of power in the core capability of that instrument. I’m excited to add to that with control and advancement and making it even easier to use. That’s an exciting platform for me to come in and understand more.
Karim Mouneimne That’s great. Out of the box thinking and not trying to fall on the common understanding but trying to go beyond that, I think always brings improvement in this field. It’s not always easy to bring innovation to this field yet keep that stability. What tips do you have for designing test equipment for engineers, even for our engineers and our customers. What are the most common mistakes that engineers make?
Troy Nickel We talked about usability a lot. So, I won’t talk too much more about that, but obviously not making it usable is a common mistake. As engineers, you get so intimately in tune with what the solution is, that you have a hard time thinking about how a user will use it when they don’t know anything about this equipment. It is just a black box. That’s my biggest broad advice.
Think about how the user’s going to use it. Specifically, use it in a variety of situations like: I’m going to fill it, I’m going to warm it up, I’m going to prime it, I’m going to do all these steps. And then on the other side is how are you going to maintain it? How will you calibrate it every year? Who’s going to do that? How will it be qualified with IQ/OQ?
That’s what I’m excited about ViVitro’s capability. Maybe more than I experienced before is that with the lab and the strength in qualification of methods that we can help our customers so much more in helping them qualify their product, whether it’s AWT or pulse duplicators. And that, from a strength of the organization of ViVitro, is going to help a lot more customers.
Karim Mouneimne I completely agree. The equipment alone is already complex, but to make it stable and scalable. That’s why homemade systems sometimes get into a very hairy and tricky situation. And then the equipment alone is nothing if you don’t have the process surrounding it. You still must submit data to regulatory bodies and have data that is reliable for patient safety.
Troy Nickel The amount of work that goes into that is almost as substantial as doing the design in the first place. I think that’s so underappreciated in terms of the design is never as easy as you thought. And then actually qualifying the design is definitely often underestimated. So you add those two together and it’s often pretty inefficient to make your own test equipment.
Karim Mouneimne Troy, thank you very much for sharing your perspective on the medical device testing industry. We’re excited to have you on board, and I look forward to working with you on all the exciting R&D projects that we have.
Troy Nickel Me too. It’s exciting to be here. Thank you very much,