A Medtronic engineer shares lessons from the adaptive deep brain stimulation project

The biggest technical challenge for aDBS is how small brain signals are, said Medtronic engineer Scott Stanslaski.

Seventeen years before Medtronic’s recent FDA approval for the world’s first adaptive deep brain stimulation (DBS) system for Parkinson’s disease, Scott Stanslaski was just starting his work on the project.

Stanslaski — who’s now a senior distinguished engineer in Medtronic’s neuromodulation operating unit — was part of the team trying to learn more about the brain signals associated with Parkinson’s and how they changed with medication or sleep.

“Part of that initial phase was to design a device that we could put into research studies, and then both learn about the physiology effects but also learn about how to design our devices better,” Stanslaski said in an interview with Medical Design & Outsourcing ahead of the project’s latest milestone.

DeviceTalks Minnesota: Learn more from Stanslaski at our Minneapolis show on June 11, 2025

How Medtronic developed and designed devices for aDBS

Around 2007, Stanslaski and his team took the Activa neurostimulator (which a decade earlier became the first FDA-approved DBS therapy system for Parkinson’s) and added brain sensing.

“By doing that, we could make just an incremental design change and then try to start learning from it,” he said. “We went through three learning cycles to get to the device we have now.”

The first was the Medtronic Activa device, followed by an improved rechargeable research device, and then the technology that led to Percept and adaptive DBS (aDBS).

Previously: What is aDBS? Medtronic VP and Brain Modulation GM Amaza Reitmeier explains

“Our first device was pretty limited in terms of the number of frequencies we could monitor as well as stimulate at and do both those at the same time,” Stanslaski said. “… Parkinson’s patients, depending on the patient type, can need different stimulation frequencies to appropriately treat their disease, so you need to build the electronics to be flexible, to stimulate at multiple different stimulation frequencies and still record the sense signal.”

“That was really where a lot of those revisions took place to try to accomplish that,” he continued. “We were also trying to become more efficient with how we did it so when you deploy this into a commercial product, the amount of energy that we were consuming to deliver the therapy was a manageable level.”

The team had their initial human cases in 2013 and learned enough to demonstrate aDBS in that first modified Activa device in 2015.

“Once we saw that and thought we could do it, we had enough momentum to start that rechargeable product design,” Stanslaski said.

The biggest technical challenge over all those years was how small brain signals are. At just a couple of microvolts, those signals are easily drowned out by the volts (1 million times greater than a microvolt) of stimulation energy being delivered.

One big advance early on with the modified Activa device was building amplifiers with low energy consumption and the ability to perform at extremely low noise levels. A later advance — made on the rechargeable device in parallel with work on Medtronic cardiac devices — was digitizing the signal after amplification within an implant for digital signal processing (DSP).

Another challenge was working with four-electrode stimulating leads that weren’t designed for sensing.

“One of the things that would happen to them is you could get fluid ingress into the lead body, and that would degrade your ability to sense brain signals,” he said. “You could still stimulate because those levels were high, but they were more difficult to sense with.”

Around 2015, they pushed ahead with a brand new lead built for brain sensing with eight electrodes. Those new SenSight leads were designed for directional sensing to minimize signal interference and featured new materials and a new manufacturing method.

Stanslaski declined to go into too much detail for competitive reasons, but discussed more generally how the team addressed fluid ingress.

“When you’re building a lead that’s going to go into your brain, it’s got to come out of the skull, go down the back of your neck and then into the chest,” he said. “The insulation materials have to be free of any pinhole defects, and that’s true for both the outer insulation as well as the inner insulation between the eight wires running back for each lead. And for the metal electrodes inside the brain, how the sealing around those electrodes occurs is also critical. You have to prevent any kind of fluid from getting up into the lead body.”

Lessons learned from Medtronic’s aDBS project

One lesson the team learned the hard way was that testing a device before shipping it out can cause unexpected problems. When deploying those first Activa research devices, the team inserted a pin block to connect each one to test equipment and verify it functioned as intended.

“As we tested multiple devices, we ended up finding [the pin block] was cutting some of the inner seals of the implantable neurostimulator,” Stanslaski said. “While that didn’t impact the stimulation, it had a big impact on the sense performance. We started seeing that both in our animal studies as well as some of the initial human implants, so we had to go off and try to figure out how it was happening and make corrective actions for it.”

“It was a really good learning experience,” he continued. “You’ve really got to think through both the design of the device but also how you’re testing and manufacturing it.”

Asked for advice he’d offer to other device engineers, Stanslaski encouraged them to “have a tremendous amount of persistence to keep at it, both to solve the technical problems, but also to make sure you’re communicating where you’re having trouble, where you’re not having trouble. That’s really big.”

“And in engineering, the more you can be in the lab testing and learning, there’s no substitute for that because you can only learn so much from computer simulations and reading papers,” he continued. “Until you really have it in the lab — and for us, doing our animal experiments — there’s just no replacement for how much you can learn in those environments. And that persistence to keep learning as you’re going throughout your whole career is just so important.”

Stanslaski credited his team’s collaboration with other teams within Medtronic, as well as feedback from physicians treating patients, for the project’s success.

“It was definitely a back-and-forth with them both during the design phase, but also physicians had the willingness to let us be there for patient visits,” he said. “I personally think that was one of the more valuable things for me, because I learned so much about Parkinson’s disease just being there and seeing what the physicians went through with the patients. And then you start to see, ‘Oh, wow, that’s a pain point right there, and we can pretty easily solve that.’ That collaboration is really important.”

The patients are another group of crucial collaborators. Stanslaski said he often traveled to research sites like Stanford University and the University of California San Francisco to meet with Parkinson’s patients offering their own assistance with the project.

“It gives them this new sense of purpose, almost like they’re coming to work. You’re learning from them, and they’re getting to see their own brain signals,” he said. “It’s a pretty enjoyable research environment.”

One interaction that stood out for Stanslaski was a January 2025 trip to Europe when Medtronic earned a CE mark for aDBS.

“He was a Dutch patient who couldn’t speak English, but he was so excited to have me there,” Stanslaski said. “He hugged me three or four times throughout the visit. That [felt] pretty good.”

Read more: This Medtronic innovation ‘could be the biggest thing we ever do,’ CEO Geoff Martha says