Radio Waves and Medicine: Cure or Witches Brew? Part1
RF radiation is everywhere in medical facilities! We can’t smell it, see it, hear it or touch it, yet we know it is out there. It has beneficial therapeutic applications. Other times it can be downright mean!
Medical diagnostic equipment provides unreliable results. Weird audio can be heard through testing equipment. Rock and roll music accompanies a medical diagnostic test. Wheelchairs motor of on their own!
These gremlins may be caused by high-power RF installations like radio and TV stations as much as several miles away. Or, they may be right around the corner. Guard radios, EMT trucks, WLAN’s, MRI, and linear accelerators can add to the brew.
Medical equipment manufacturers work hard to provide immunity in their products, but user setups vary, and problems slip through; sometimes with unfortunate consequences.
Case Study: A neurologist was testing his new Neuro-Conduction/EMG machine. When applying the concentric needle to his wrist, he noted that his arm was dancing to clearly heard rock music!As an amateur radio operator, he was quite conversant with radio frequency and understood that this behavior by the machine was connected in some way to outside signals.This particular interference was traced by LBA engineers to an AM radio station a mile away. LBA supplied an RF shielding design and materials, which were quickly and economically installed by his builder in the exam rooms, that solved the problem. On a technical note, the LBA engineer detected a signal of about 1 Volt/meter emanating from the radio station. Federal Communications Commission(FCC) guidelines suggest that RF interference problems with electrical medical equipment can be elicited within the 1 V/m field of a radio station. Go to the free LBA Toolbox to see if there are any broadcast stations threatening your facility.
In our next installment, we have more on medical RF interference – check back soon.