Well, in general, with a medical device you're dealing with two federal agencies and their respective sets of regulations.
First - FCC regulations. These RF emissions standards are fundamentally aimed at preventing interference and device susceptibility to such interference.
Second - FDA Regulations. The FDA is charged with governing and maintaining the safety of medical devices, among other things. Part of that mandate relates to devices that emit radiation of any kind, whether ionizing or not, and whether such emissions are considered "safe" for humans.
Thus, the developers of the MRI had to prove by scientific measurements and by trials upon animals and humans that the RF and magnetic energies 'emitted' by the machine were "safe". Here, both radiation levels and duration of exposure enter the equation. So do risk vs benefit calculations. Thus, an X-ray does harm to the DNA, but the benefit often outweighs the risk. But soon the calculation over time for total permitted exposure increases the risk to a point that X-ray may be contraindicated for a particular patient - but that has nothing whatever to do with device approval by the FDA. That falls under the bodies that govern conduct of medical professionals.
In general, a medical device may intentionally irradiate the patient, aimed at producing some benefit. The mfg of the device has to prove to the FDA by scientific methods that such a benefit, and no unacceptable harm, accompanies the use of the device.
So, as such, the FDA does not maintain and enforce the same kinds of standards that the FCC does. FCC emissions standards are precise and unyielding. FDA standards are more embodied in principles, such as that central one mentioned in the previous paragraph.
So, using the MRI as an example again, the device could never pass FCC emissions standards unless it is enclosed in a very expensive Faraday room - and it always is so enclosed. But you can stand in the room near the MRI while your friend or spouse is 'in the tunnel' and, as long as you don't have steelies in your pocket, and there isn't a steel gas cylinder of some kind laying around unlashed, you'll be just fine!
So a medical device can 'get away with some emissions' that a non-medical device can't - as long as the emitting device is only used in a properly shielded room.
In the case of my medical device, I'm intentionally emitting infrared optical energy, but not intentionally emitting RF. I want to prevent RF emissions that are in violation of the FCC standards and, if I do so, I can be reasonably sure those emissions will also be safe for human exposure. However - the FDA isn't going to listen to such logic. It will insist I prove not only that the optical emissions are both safe and effective, but also that the RF emissions are safe. The only way I can prove the latter is to bring to bear on my case the longstanding science that such low levels of RF emissions in intimate contact with the skin have never been proven to be harmful. Then I have to conduct trials on humans and document the results.
A cert from a lab that my RF emissions are within FCC standards is going to be crucial in making my case to the FDA, but they won't accept that alone. Thus, in effect, the bar for medical devices is set quite high - this is as it should be.
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