Image Credit: Elena Scotti/Gizmodo/GMG, photos via Shutterstock

In 2009, Gary Olhoeft walked into a Best Buy to buy some DVDs. He walked out with his whole body twitching and convulsing. Olhoeft has a brain implant, tiny bits of microelectronic circuitry that deliver electrical impulses to his motor cortex in order to control the debilitating tremors he suffers as a symptom of Parkinson’s disease. It had been working fine. So, what happened when he passed through those double wide doors into consumer electronics paradise? He thinks the theft-prevention system interfered with his implant and turned it off.




We live in a world of many, many signals. The more signals there are, the more opportunity for them to cross—and for people with implanted devices, the effect can be disastrous.

Olhoeft’s experience isn’t unique. According to the Food and Drug Administration’s MAUDE database of medical device reports, over the past five years there have been at least 374 cases where electromagnetic interference was reportedly a factor in an injury involving medical devices including neural implants, pacemakers and insulin pumps. In those reports, people detailed experiencing problems with their devices when going through airport security, using massagers or simply being near electrical sources like microwaves, cordless drills or “church sound boards.”


While not every one of those reports has been verified, both the FDA and scientists have expressed concerns about scenarios where ambient electromagnetic fields disrupt medical devices that operate in the same frequency spectrum.

“The consequence of EMI [or electromagnetic interference] with medical devices may be only a transient ‘blip’ on a monitor, or it could be as serious as preventing an alarm from sounding or inappropriate device movement leading to patient injury or death,” the FDA wrote in a report all the way back in 2000. “With the increasing use of sensitive electronics in devices, and the proliferation of sources of EM energy, there is heightened concern about EMI in many devices.”

Scientific study has been devoted to the impacts of this kind of interference on brain implants, cardiac implants and insulin pumps. The conclusion: As more devices both in our bodies and the built world operate on a frequency, the problem is likely to grow in scope and scale unless we plan carefully.

Olhoeft, who had just recently gotten his implant, at first had no idea why his trip to the store had triggered his tremors. “Without the implant, the tremors were so bad that I couldn’t walk or talk,” he told Gizmodo. “After they installed it, I had no symptoms until I walked into that Best Buy. Then within four seconds I started to shake again.”


Later, at his doctor’s office, Olhoeft found out that the device had somehow been switched off, right around the time he’d gone to Best Buy. Olhoeft is a retired professor of geophysics in Colorado who taught courses on electromagnetism, so with those two details, it wasn’t hard for him to figure out what had probably gone wrong. His implant, he says, operated at the same electromagnetic frequency as Best Buy’s theft detection system, and the two signals interfered with each other.

“When you get an implant, they warn you about interference with devices like MRI machines. But they don’t warn you about Best Buy or Walmart,” he said. “I go to a support group for people with deep brain stimulation implants and I gave a talk about interference. I asked how many people had an experience like mine at Best Buy and all 50 people put their hands up.”


“When you get an implant, they warn you about interference with devices like MRI machines. But they don’t warn you about Best Buy or Walmart.”

Like Olhoeft said, it’s not that no one had warned him. In its manuals, Medtronic, the maker of the device, clearly advises patients that things like hairdryers, cell phones, power tools, and yes, in-store security systems may impact devices. The patient manual for Medtronic’s deep brain stimulation devices has an entire appendix to potential sources of EMI, and the consequences for not heeding these warnings that it lists are dire: system changes, changes to stimulation, injury or even death.


The trouble is, as medical implants become not only more ubiquitous, but more connected, so does the rest of the world. And device makers have to not only plan for devices that work in today’s environment, but hopefully also a decade down the road, when patients still have the same implant but the world of signals around them may be substantially different.

“The internet of things, wireless power transfer, electronics in cars, cellular smart meters, nonlethal crowd control, there’s an endless list of new rapidly emerging electromagnetic technologies that have to be tested” for possible interference, Olhoeft told Gizmodo.


“You can think to some degree about changes that may come down the road, but typically those changes you anticipate are only extensions of what you already know,” said Frank Fischer, the CEO of NeuroPace, which makes brain implants that target epilepsy.

How, for instance, will a world with autonomous vehicles, with features like wireless charging and radar sensors, impact patients with brain implants or pacemakers? Or, in the more distant future, what if we’re all walking around with implants that make us smarter, and treat our depression? How will this complex world of signals interplay then?


“I don’t think you’re ever going to be able to foresee the future,” said Fischer. “In reality, what you want to do is make sure that when things do go wrong, a device goes into some kind of safe mode and then allows a patient to reset it.”

Medtronic, which makes Olhoeft’s device, echoed this sentiment in a statement to Gizmodo. “While our product testing is extensive, we cannot account for all possible scenarios,” the company said. Though “most electrical devices and magnets encountered throughout the course of a patient’s typical day,” are unlikely to have any impact, there’s really no guarantee.


“In reality, what you want to do is make sure that when things do go wrong, a device goes into some kind of safe mode and then allows a patient to reset it.”

Every day since that one at Best Buy, Olhoeft has navigated the terrain of that ambiguity. He’s discovered that the airport security checkpoints, his local hall of justice, and sports arenas all operate near the frequency of his device and could potentially interfere with it . To test such situations, he uses a detector that tells him the frequency of things like security systems to make sure they’re operating on a different frequency than his device. If the frequency is a match, he asks to go around. When he goes to his university library, he has to ask them to turn off the inventory control system so that he can enter, and at the hospital he steers clear of walking too close to the MRI machine. In his own home, he and his wife took out the dimmer switches on all the lights, which have their own small electrical field. So does the AC unit and the fridge. Since having his implant installed, he’s discovered that the world is a minefield of potential interference that in an instant could potentially send his body into debilitating shaking.


It’s all precautionary, in hopes that he can avoid those worst-case scenarios listed in his patient manual.

Olhoeft has heard from other patients like him that have had trouble with their implants and interference. One woman who had a DBS implant like his found that when her Prius was in charging mode, it turned her device off. Another man had a DBS, cochlear implant and cardiac pacemaker that all operated near the same frequency and interfered with the operation of the devices.


The medical device industry shares Olhoeft’s concerns. In collaborations with makers of things like RFID chips that emit potentially interfering signals, medical device makers have been working out how to minimize exposure of patients like Olhoeft to harmful interference, and educate patients to be cautious.

“It’s something we have to design for and in my lab we have to think about it a lot,” said Alik Widge, a biomedical engineer at Harvard who works on DBS implants for mental illness. “It’s a huge potential problem.”


Thankfully, there are potential solutions. Increased security and encryption, for one, could help make it so that devices couldn’t be impacted by errant signals. So could improving the safe modes of devices, as Fischer mentioned. While Olhoeft’s device does have a safe mode, it has to be manually set and is intended for situations when he knows he’s going to come into contact with interference, like during operations or an MRI.

“It would be better if it were automatic,” he said.

The FDA, too, has worked to create guidelines for device manufacturers so that they can build medical devices more likely to be compatible with their increasingly electronic environments. Recently, it finished creating guidelines that also address wireless compatibility, to look at how medical devices that communicate wirelessly interact with the ever-growing internet of things.


“Things are changing quickly, and medical manufactures are making an effort to try and deal with problems before they become big issues,” said Donald Witters, a biomedical engineer at the FDA’s Center for Devices and Radiological Health. “We spend a great deal of time trying to keep abreast of wireless communications and internet of things technology. It’s hard to predict the impact these things will have, but we can try and position ourselves to ask the right questions.”

Joel Moskowitz, the director of the Center for Family and Community Health at Berkeley’s school of public health, told Gizmodo his concern is that as these issues become more prevalent, doctors may not be aware of how to advise their patients.


Olhoeft, whose implant is now six years old, from an era when the iPhone was still a novel technology, wonders how it might restrict his life in the future. He has become something of an advocate for the issue, speaking out about his own experience, sending comments to the FCC and suggesting to the Department of Justice that implants like his should be recognized as a disability, since it requires him to navigate cautiously around a world built for people without bodies that emit electromagnetic signals.

“We’re going to have to consider using the Americans with Disabilities Act for people with implants,” he said. “You know, ‘Warning, people with implants should not enter here.’”