



Doctors and researchers have used MRI machines for over forty years to create detailed images of internal organs and tissues. But do MRI machines play well with other modern inventions? One Reddit user recently reported that an MRI machine zapped every iOS and watchOS device in his facility.Redditor u/harritco remarked that he had experienced the “most bizarre issue I've had in my career in IT”. A medical facility had installed a new MRI machine and by the end of the day every iPad iPhone , and Apple Watch had been disabled. More than forty people were affected by the issue, but no other devices, other than iOS devices, seemed to be impacted. All Android devices and other electronics were unscathed.Why would an MRI machine only affect iOS devices? Redditor u/harritco called General Electric ( GE ) and they believe that a helium leak was the cause for the incident. Redditors u/captaincool and u/luckyluke193 provided further explanation in a Reddit response.Most modern devices incorporate microelectromechanical system (MEMS) oscillators. MEMS oscillators resonate frequencies that can be used for a variety of tasks such as measuring time. These resonators are placed in hermetically sealed chambers in devices, because they can easily be affected by small atomic gasses like helium. Unfortunately, the sealed chambers are not perfect and can be rather cheaply made allowing Helium at higher atmospheric concentrations to leak through the seal and increase the pressure in the chamber. The redditors theorized that most iOS devices probably share similar MEMS oscillators to reduce costs.Redditor u/harritco reported that 120 liters of liquid helium leaked over a five hour period. The expansion ratio of liquid to Helium gas is 1 to 757. The MRI shares its air with most of the facility so about 90,000 cubic meters of Helium gas filled the building. Only a small bit of helium would be needed to disable the iOS devices. It is thought that if enough time passes (a week or more), that the devices “may” return to normalcy, but that isn’t guaranteed. In this case, all of the affected devices are being replaced by the company so that its employees aren’t left without their phones or tablets.Why were the Android devices not affected? The devices likely have different MEMS oscillators made with different specifications. The moral of the story seems to be do not bring an iOS device to a MRI fight.