The Federal Communications Commission (FCC) regulates wireless medical devices in conjunction with the Food and Drug Administration (FDA), with the FCC’s role related to certain technical concerns such as the successful sharing of wireless frequency bands. Another area that FCC regulates is radio frequency (RF) safety – the possible harmful effects to human health from RF energy created by wireless devices. The FCC looks to health and safety agencies such as the FDA, the Environmental Protection Agency (EPA), and the Occupational Safety and Health Administration (OSHA) to provide guidance and recommendations on what level of RF emissions are deemed “safe,” and then sets rules for how responsible parties must evaluate compliance with these limits. These rules on safe emission levels apply generally to devices that produce RF signals. Therefore, unless exempt, smaller handheld or portable medical devices may be required to be tested for, and meet, specific absorption rate (SAR) criteria.
The FCC proposed modifications to its RF safety rules in 2013, and finally, on December 4, 2019, issued a decision that adopts many of its proposals. The following items relate to wireless medical devices:
- No Changes to the Actual Exposure Limits: Announced months earlier, based on input from the safety agencies, the FCC determined that no changes to the allowable exposure limits to RF emissions from wireless devices are necessary. That is, the U.S. position is that the current limits, which differ from some international standards, are sufficient to protect human health. Therefore, manufacturers need not make changes to current designs to lower RF emissions or to otherwise decrease user or patient exposure.
- Modification to Exemption Categories: To ensure that similar devices operating on similar frequency bands are treated in the same way, the FCC has established three classes of devices that can be exempt from the RF testing rules. Each class of device is subject to a calculation that considers both power level and the separation distance of the RF energy source from humans. These new rules offer a broader exemption from RF testing for certain wireless devices, specifically those that operate at low power levels (no more than 1 mW average power or lower). This means that some low-power wireless medical devices that previously were subject to testing may be exempt.
The FCC did not adopt a recommendation by some in the medical implant community to provide for more relaxed rules for moderate-power wireless medical devices (20 mW average power, which equates to 2 W/kg averaged over 10 g of tissue), a level that some international standards bodies have adopted. This means that as medical device manufacturers move toward designs with greater power to accommodate growing wireless communications capabilities, more and more medical devices may fall outside the exemptions and may need to be tested for RF safety.
The FCC seeks comment on proposed rules addressing appropriate exposure levels and testing for devices operating in additional frequency bands – below 100 kHz and above 6 GHz. Manufacturers of medical devices designed for these frequency ranges may wish to submit comments supporting or opposing the proposed exposure limits and calculation methodologies for these bands.