Anesth Analg 2006;103:1043
© 2006 International Anesthesia Research Society
doi: 10.1213/01.ane.0000239029.30328.50
LETTER TO THE EDITOR
Editor-in-Chief Steven L. Shafer
November 2005 Food and Drug Administration Alert: Risk of Electromagnetic Interference with Medical Telemetry Systems Operating in the 460–470 MHz Frequency Bands
Roy G. Soto, MD, and
Keith J. Ruskin, MD
Department of Anesthesiology; Stony Brook University; Stony Brook, New York; roy.soto{at}stonybrook.edu (Soto)
Departments of Anesthesiology and Neurosurgery; Yale University; New Haven, Connecticut (Ruskin)
To the Editor:
In our recently published article (1), we discussed the very low probability electromagnetic interference between wireless communication devices and medical equipment and compared that risk to the improvement of patient safety with the use of cellular telephones in the OR/ICU environments. In November 2005, the United States Food and Drug Administration (FDA) published a clinical alert stating that licenses will soon be issued for mobile radio transmitters (which are separate and distinct from that of cellular telephones) operating at frequencies between 460 and 470 MHz, a band that has previously been used for medical telemetry (2). The band will be allocated to the land mobile service (for instance, as used by fire and police departments), with medical telemetry becoming a secondary user. The statement warned that opening this band to radio transmission could "lead to lapses in patient monitoring and missed alarm events, putting patients at risk." Although this seems like a dire warning, the actual consequences will probably be insignificant.
Electromagnetic interference occurs when devices that generate radio frequency energy interact with medical devices with insufficient shielding. To avoid this problem, in 2000, the Federal Communications Commission allocated specific bands frequencies between 608 and 614 MHz, 1395 and 1400 MHz, and 1429 and 1432 MHz (3) to medical telemetry systems. As a result, any devices placed on the market after 2000 would not fall within the newly opened band referenced in the FDA alert. Most medical devices that used the old 460–470 MHz frequencies are being removed from service.
We therefore recommend that users who purchased wireless telemetry equipment before 2000 contact their institution's biomedical engineering department to determine whether their equipment will be affected by these changes.
REFERENCES
- Soto R, Chu L, Goldman J, et al. Communication in critical care environments: mobile telephones improve patient care. Anesth Analg 2006;102:535–41.[Abstract/Free Full Text]
- FDA. FDA 2005 Alert safety alerts for drugs, biologics, medical devices, and dietary supplements. Available at http://www.fda.gov/medwatch/safety/2005/safety05.htm#EMI. Last accessed on November 16, 2005.
- FCC Order establishing Wireless Medical Telemetry Service (WMTS). 2000. Available at http://www.fcc.gov/Bureaus/Engineering_Technology/Orders/2000/fcc00211.doc. Last accessed on June 2000.
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