What are the RF emission limits for medical devices operating in the ISM bands?

The RF emission limits for medical devices operating in the ISM (Industrial, Scientific, and Medical) bands are governed by multiple regulatory frameworks depending on the device's intended use and operating region. ISM bands commonly used by medical devices: 13.56 MHz (RFID, NFC for patient tracking and implant communication), 433 MHz (some EU medical telemetry), 915 MHz (US ISM band; medical body sensor networks), 2.45 GHz (diathermy, medical telemetry, Wi-Fi-based medical systems), and 5.8 GHz (some medical monitoring devices). Regulatory framework: FCC Part 18 (ISM equipment): applies to devices that intentionally generate RF energy for purposes other than communications (e.g., diathermy, electrosurgical devices, MRI). Emission limits: the device must not cause harmful interference to radio communications. Limits are specified in terms of radiated emissions at specific distances. FCC Part 15 (unlicensed communications): applies to medical devices that communicate wirelessly (telemetry, remote monitoring). Must comply with Part 15 emission limits for the specific frequency band (e.g., Part 15.247 for 2.4 GHz ISM band). IEC 60601-1-2 (medical device EMC): the international standard for electromagnetic compatibility of medical electrical equipment. Specifies both emission limits (to prevent the medical device from interfering with other equipment) and immunity requirements (to ensure the medical device operates correctly in the presence of electromagnetic disturbances). Emission limits align with CISPR 11 (Group 1 or Group 2, Class A or Class B, depending on the device type). FDA regulatory approval: medical devices sold in the US must also comply with FDA requirements (510(k) or PMA), which include EMC verification per IEC 60601-1-2 as part of the device's safety and effectiveness evaluation.