‘A mini-engineering feat’: High-tech headphones drown out the scary noises inside an MRI

For many people, entering the confinement of an MRI machine can be harrowing: Scans can take hours and patients must lie very still in cramped machines that produce deafening sounds.

But a new, high-tech effort aims to ease claustrophobia and deaden the noise to make it less like a scary scan and more like entertainment. 

“Hopefully you would think about it more in terms of what it’s like to go into a movie theater now,” said Mark Cohen, a functional MRI researcher at UCLA.

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Cohen is part of a team of scientists, designers, and engineers who have been working since 2016 with a company called SMRT Image to create a sophisticated audio-visual system to keep patients comfortable. Besides making the experience less unpleasant, the technology could cut down on the number of rescans needed because an anxious patient is squirming inside the machine, and could convince patients who otherwise might opt out of an MRI due to discomfort to come in for the scan.  

It’s an impressive example of how tech expertise outside the world of medicine could help make an impact on patient well-being.  

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Every component of the new system, called Lumica, had to be designed to account for the harsh conditions of an MRI scan. SMRT Image added a rear laser projection system placed behind the machine, which patients can watch video on through a wide-view mirror. It can be reconfigured to adapt to multiple scanning positions and machines, including PET and CT scanners. 

There’s also a two-way communication system that allows technicians and patients to communicate and see each other during the scan, and noise-cancelling headphones developed in partnership with Audeze, a Santa Ana, Calif.-based company that specializes in pricey products for audiophiles.  

“You don’t get to do something like this all the time when you’re running a consumer products company,” CEO Sankar Thiagasamudram told STAT. “There’s a chance that we could make something that actually is very useful, not just a headphone that is, you know, $5,000.”

Thiagasamudram first met with Cohen about the idea in 2016, when a nebula of collaborators was coalescing around the concept of creating a better version of the rudimentary audio-visual systems used in research. Cohen has spent decades studying what parts of the brain are activated by different stimuli, which can be examined with a functional MRI. At the time, he had been working with an LA-based creative agency and venture incubator called Boombang to develop a better stimulus device for his lab. Eventually, they realized the technology had broader potential.

“Since the time I started doing fMRI exams 30 years ago, until now, I have probably had one, maybe two refusals in the scanner for discomfort for the research studies,” said Cohen. “The message there is that if people are mentally occupied when they’re in there, the whole process is a whole lot easier.”

After years of work, the Lumica system features more than 600 parts that have been custom developed or sourced from all over the world, Boombang founder and CEO Tylor Garland told STAT.

“Every piece of it has been a mini-engineering feat,” he said. 

The headphone technology in particular required complete reinvention. Most headphones use metal and magnets that can’t be brought into an MRI machine. And while some headphones work in the machines, they’re low quality and don’t account for the disquieting sound the machines make. 

The system’s solution, in part, is a sophisticated electrostatic headphone design that delivers a high sound quality without the use of magnets. Conventionally, electrostatic headphones require a very thin diaphragm coated in a conductive metal, are very large, and require powerful external amplifiers — all no-gos inside an MRI. To get around those problems, Audeze turned to carbon nanotubes to create the film and used glass, rather than the usual metal, for the plates that surround it.

Using the carbon nanotube material made the size of the headphones scalable, so in addition to a full-size model, there will be a child-size model, and a tiny in-ear model.

The amplifier powering the system was designed to sit far away from the MRI machines and, and the researchers replaced traditional copper wires with optical wiring, which was meticulously shielded.

Traditional noise-canceling circuitry also had to be redesigned to sit far away — instead of inside of — the headphones. A microphone array on the headphones captures the MRI’s noise signal, and it’s piped away via shielded cable for processing. The noise is canceled by producing an opposite signal.

“Once we made the first full version, we realized this is perhaps the best sounding headphone we have ever made,” said Thiagasamudram, who said the company plans to start selling a $4,500 consumer version without noise cancellation in August.  

SMRT Image will pilot 100 systems in hospitals and imaging centers this year under a new subscription-like business model. It’s also in conversations with some distributors. If all goes well, Garland said, the company plans broader expansion next year. 

Source: STAT