EMC MDQS Page 5
GUIDE TO INSPECTIONS OF ELECTROMAGNETIC
COMPATIBILITY ASPECTS OF MEDICAL DEVICE
for conformance to these requirements and who will certify conformance to the standard. Because expensive equipment and facilities are needed for other than ESD testing, independent laboratories and larger manufacturing firms are more likely to have the capability of testing products for conformance with EMC standards than are smaller manufacturers.
Any certification or declaration of conformance to IEC 60601-1-2 or other EMC standard should be supported by the following types of documentation, including appropriate justifications:
- applicable collateral or particular standards that were used.
- any EMC requirements that are not applicable to the device.
- test levels, pass/fail criteria, variances from test criteria, and pass/fail results.
- any differences between the tested device and the device to be marketed.
- name and address of the certification body and by whom and how it is accredited.
- other EMC standards and guidelines applicable to the particular medical device. (See Appendix B.)
21 CFR 820.30(g) Design Validation
Validation is use of the final device to determine if it operates as intended in the expected use environment.
Example: A laboratory test exposing the device to 800-900 MHz fields is verification, while trial use of the device in a clinic where cellular phones are used in adjacent rooms is validation.
Validation activities for EMC may include clinical evaluations or use simulations. They should be conducted on production devices or the manufacturer should demonstrate how the tested devices are equivalent to production devices. Some EMI may be considered clinically acceptable if the hazard is reduced as much as possible through design and adequate precautions, warnings, and instructions for safe use are provided.
Both hardware and software can affect EMI responses so validation should address EMI of an integrated system, especially if verification of hardware and software were done separately. Also be aware that since cellular telephone systems, other transmitters, and electrical supplies are different in foreign countries, devices intended for export may undergo unusual validation methods.
21 CFR 820.30(i) Design Changes
For devices already being produced and marketed, EMC may be addressed for the first time during design changes. A device manufacturer should determine the criteria for when and how EMC specifications will be added to the design process.
DEVICE LABELING CONTENT
Labeling in place of design controls usually is not adequate to prevent adverse events. It should supplement EMC design and testing to address any precautions that need to be taken by users despite the design considerations.
Users can enhance safety and effectiveness of devices susceptible to EMI if they are provided clear guidance for avoiding, identifying and resolving EMI problems, information on conformance to existing standards including how testing was done, and possibly recommended separation distances from other devices or EMD sources. Adequate labeling is particularly important if the device is often used in high field strength environments and cannot be made to function as intended in these environments. If a device cannot meet applicable test requirements, if certain tests have been omitted, or there are competing safety issues, device labeling may be used to warn the user of the potential of EMI from exposure to outside EMD sources and/or of emissions from the subject device that may affect other equipment.
If a firm makes a declaration of conformance to IEC 60601-1-2, that standard specifies that the labeling include:
1. guidelines for avoiding or identifying adverse electromagnetic effects;