Electromagnetic Compatibility - A Letter to Industry
DATE: September 18, 1996
TO: Registered Medical Device Manufacturers, Firms Filing Electronic Product Radiation Reports, Related Trade and Professional Associations
SUBJECT: Safety of Electrically Powered Products
The Food and Drug Administration (FDA) is aware of a safety issue that affects users of all electrical products. Specifically, electromagnetic interference is resulting in hazards to users and operators. Our purpose in writing to you is threefold: 1) to inform you of our involvement, 2) to encourage interchanges between professional and trade associations (medical and non-medical) to develop solutions, and 3) to ask you to re-assess your product designs.
The FDA's Center for Devices and Radiological Health (CDRH) administers the Medical Device provisions and the Electronic Product Radiation Control provisions of the Federal Food, Drug, and Cosmetic Act to assure public health and safety. As a public health agency, we strive to minimize risks to patients and users of medical devices and electronic products.
We are concerned about the response of electrically-powered products exposed to various electromagnetic environments and the consequences of that response. CDRH has received reports of malfunctions of medical devices and radiation-emitting electronic products due to electromagnetic interference (EMI), including radiated emissions, conducted emissions, and electrostatic discharges. Sometimes the consequences were severe even though emissions were within currently accepted limits; for example:
- a monitor failed to detect a patient's critical condition,
- a defibrillator failed to resuscitate a patient,
- a wheelchair suddenly moved toward street traffic,
- a laser beam went into the audience area of a light show,
- a radiation beam shutter did not close.
Electrically-powered products can be sources of EMI, or unintentional receivers of electromagnetic fields, or both. The increasing use of electronics, proliferation of electromagnetic sources, and lack of electromagnetic compatibility (EMC) testing for many products has led CDRH to begin developing a strategy for EMC. This strategy includes development of pre- and post-market guides, standards, educational programs, and research for medical devices, and development of post-market assessment, educational programs, and research for radiation emitting electronic products, both medical and non-medical.
We are encouraging various industries whose products are used in the same environments to begin discussions about designs and environmental controls. To this end, CDRH co-sponsored a Forum on Electromagnetic Compatibility in May 1995 (see enclosed list of references). CDRH also is planning a teleconference on this issue for mid-1997; it will be announced in trade publications and on the Internet. Our home page (http://www.fda.gov/MedicalDevices/default.htm) soon will have EMC information, listed under "Program Areas."
As the medical device industries prepare for the inclusion of design controls in their quality systems, we encourage device and electronic product industries to use standards that address EMC, such as IEC 601-1-2. We also remind user facilities that device malfunctions, including EMI-related ones, may be reported to the FDA MedWatch program by phone at 1-800-FDA-1088; by FAX at 1-800-FDA-0178; or by mail to MedWatch (HF-2), FDA, 5600 Fishers Lane, Rockville, MD 20857; manufacturers must report them to FDA/CDRH, Medical Device Reporting, P.O. Box 3002, Rockville, MD 20847-3002. Non-medical radiation incident reports may be sent to FDA (HFZ-342), 2098 Gaither Road, Rockville, MD 20850.
If you would like copies of information we have available, contact the Division of Small Manufacturers Assistance (DSMA) as specified on the enclosed list of references. General inquiries regarding EMC should be directed to DSMA's Communications Section, preferably by facsimile at 301-847-8149 or by telephone at 1-800-638-2041.
Lillian J. Gill
Office of Compliance
Center for Devices and