Electromagnetic Compatibility (EMC) Standards
The U.S. FDA issued a voluntary standard MDS-201-0004 in 1979 specifying that radiated immunity of medical electrical equipment should be 7 V/m from 450 MHz to 1000 MHz. The international collateral standard IEC 60601-1-2 on electromagnetic compatibility for medical electrical equipment states that an immunity of 3 V/m shall apply for the frequency range from 26 MHz to 1000 MHz. However, a higher level of immunity was proposed in recognition of risks to life-support equipment. The draft second edition of the IEC 60601-1-2 proposes 10 V/m for life-support equipment and 3 V/m for other medical electrical equipment for the frequency range from 80 MHz to 2.4 GHz. However, immunity of 10 V/m does not guarantee that EMI effects will not occur. In addition, IEC 60601-1-2 (1st edition) requires testing with 1 kHz amplitude modulation at a single modulation frequency. The draft 2ndedition proposes testing at 80% amplitude modulation at 2 Hz if the physiological simulation frequency and operating frequency of the medical device under test is less than 1 Hz or greater than 3 Hz, and it is no longer required to test at 1 kHz. The need for establishing specific EMC standards for medical electrical equipment and systems is well recognized. Designing medical devices to be immune to electromagnetic fields up to 10 V/m for life-support medical electrical equipment and 3 V/m for non-lifesupport medical electrical equipment, as proposed in international standards, would greatly reduce the hazard from EMI. The ISO TC150SC6 Working Groups 1 and 2 are drafting specific EMC standards for implantable cardiac pacemakers and defibrillators
Conclusion
In conclusion, management of the use of radiofrequency sources and attention to the electromagnetic compatibility of medical devices in health care facilities will provide some assurance as to the safe use of medical devices and may prevent EMI problems.