April 28, 2008 – Engineering students at the University of Florida designed a headset that may reduce the sound of loud noises produced by MRI examinations, aiming to provide a more positive experience for patients as well as reduce the number of examinations needed.
The air phones, which are similar headphones once distributed on commercial airplanes, pipe the sound via two tubes to tiny microphones connected to an amplifier and a signal processor several feet away. That processor taps an algorithm, or set of computer instructions, to produce a sound signal that is the opposite of the signal just received. That opposite signal then gets piped back through a third tube to each of the patient's ears.
Because the MRI sounds are repetitive and the piped-in sounds are timed to occur on top of the repetitions, the result is that the patient hears the same sound as he or she would have without any intervention - but at a lower volume.
Trials of the system using a loud beeping sound similar to some MRI noises showed it could reduce the noise by as much as 15 decibels. Ambient noise is about 60 decibels, with jet engines and other extremely loud noises reaching 120 decibels. The students were only able to reduce actual MRI sounds by a smaller level, but they said further tweaks of the system and algorithm are likely to improve that result.
The team's results are "significant and make a difference," said Gijs Bosman, a professor of electrical and computer engineering and the team's faculty adviser. "Based on experiments and further testing of the prototype, the team has come up with several recommendations for further improvements."
For more information: www.ufl.edu