10.12.2 Implanted Medical Devices
Active implanted and body-worn medical devices can depend on electronic circuitry whose operation may be affected by electromagnetic interference.
Examples may include:
- cardiac pacemakers;
- implantable cardioverter-defibrillators;
- deep brain stimulators;
- cochlear implants;
- implantable or body-worn insulin pumps;
- neurostimulators; and
- implantable drug-delivery systems.
Compliance with the occupational or public RF exposure limits does not by itself establish electromagnetic compatibility with a particular device. Susceptibility depends on the device, its settings and leads, the field frequency and modulation, the field strength, distance, orientation, and the manufacturer's immunity information.
RPS S-1 requires procedures to ensure that a person who may be occupationally exposed above the public basic restrictions and has a susceptible medical device is not put at risk. An individual assessment should use the device manufacturer's information and appropriate medical, occupational-health, and RF advice. The practical guidance referenced by RPS S-1 will be sufficient for most cases; complex computation should not be assumed necessary.
10.12.3 Metallic Implants
A metallic implant does not automatically exclude a person from RF work, but it can require separate consideration from compliance with the ordinary exposure limits.
A conductive implant may alter the local field or current distribution in the body. The assessment should therefore consider the implant and the exposure configuration where the person may be occupationally exposed above the public basic restrictions. Examples include:
- orthopedic plates and screws;
- joint replacements;
- spinal fixation devices;
- vascular stents; and
- dental implants.
The significance depends on the implant's material, dimensions, location, and orientation, together with the frequency, field distribution, coupling conditions, and the work activity.
RPS S-1 requires procedures that prevent a person with a metallic implant from being put at risk when occupational exposure may exceed the public basic restrictions. The response should be based on an individual assessment and competent advice, not a blanket prohibition or an assumption that every implant creates a hazard.