Wireless Technologies and the National Information Infrastructure.
Chapter 12 - Electromagnetic Interference and Wireless Devices:
Footnotes

* CHAPTER 12 FOOTNOTES *

1. Causes of interference include high clock rate timing pulses used in computers, video games, etc., and their harmonics.
2. K. J. Clifford, et al., "Mobile Telephones Interfere with Medical Electrical Equipment," Australian Physical & Engineering Sciences in Medicine, vol. 17, No. 1, 1994, p. 23.
3. EMI effects increase with power and decrease with distance.
4. Stewart Fist, "GSM and TDMA digital phones," April, 1994, unpublished manuscript.
5. Jeffrey L. Silberberg, "Performance Degradation of Electronic Medical Devices Due to Electromagnetic Interference," Compliance Engineering, fall 1993, pp. 25-39; "Cellular Telephones and Radio Transmitters: Interference with Clinical Equipment," Technology for Respiratory Therapy, vol. 14, No. 5, November 1993; Tom Knudson and William M. Bulkeley, "Stray Signals: Clutter on Airwaves Can Block Workings of Medical Electronics," The Wall Street Journal, vol. 223, No. 116, June 15, 1994, pp. A1, A12.
6. Some documented illustrative examples:
   • A fetal heart beat detector picked up radio and CB broadcasts and static instead of heart beats.
   • A ventilator malfunctioned due to interference from a guard's walkie- talkie.
   • A user of a powered wheelchair had moved to a new home and was showing his friends, also in powered wheelchairs, around the neighborhood. While moving up a hill, the user heard clicking noises and took his hand off the joystick. The wheelchair made a sudden about turn and headed down hill at high speed. The wheelchair would not respond to further movement of the joystick. The wheelchair continued down the hill for about 25 yards, veered left, and went over a cliff. The user suffered a broken hip and several other injuries. His friends' wheelchairs were from a different manufacturer and were not affected. The wheelchair user's new home is several miles away from a radio station and three blocks from a major interstate highway.
   • An external defibrillator/pacemaker stopped pacing when an ambulance attendant used a hand-held transmitter too close to the patient. The patient was not resuscitated.
   These examples are taken from Jeffrey L. Silberberg, op. cit., footnote 5, pp. 25-39.
7. Mark Landler, "Cellular Phones May Affect Pacemakers," The New York Times, Apr. 29, 1995, p. B1; John J. Keller, "Cellular Phones May Affect Use of Pacemakers," The Wall Street Journal, Apr. 29, 1995, p. B1. Medtronic, Inc., a major pacemaker supplier in the United States, advises pacemaker users to turn off portable phones placed in breast pockets, hold phones ten inches away from the chest, and use the phone on the opposite side of the body from where the pacemaker is implanted.
8. Michael Ruger, attorney, Baker & Hostetler, Washington, DC, personal communication, Feb. 17, 1995; "TDMA Mobile Phones Accused of Interference," Microwave Engineering Europe, March/April 1993, pp. 16-17.
9. U.S. Food and Drug Administration, Bureau of Medical Devices, "Electromagnetic Compatibility Standard for Medical Devices," BMD Publication No. MDS-201-0004, Oct. 1, 1979.
10. International Electrotechnical Commission, Medical Electrical Equipment, Part 1: General Requirements for Safety, 2. Collateral Standard: Electromagnetic Compatibility--Requirements and Tests, 1993.
11. Knudson and Bulkeley, op. cit., footnote 5, p. A12.
12. U.S. Congress, General Accounting Office, Electromagnetic Interference with Medical Devices, GAO/RCED-95-96R (Washington, DC: Mar. 17, 1995).
13. U. S. Congress, House of Representatives, Committee on Government Operations, Subcommittee on Information, Justice, Transportation and Agriculture, 103d Congress, "Do Cellular and Other Wireless Devices Interfere with Sensitive Medical Equipment? Are Pacemakers, Hearing Aids, Apnea Monitors, Blood Pumps and Other Sophisticated Medical Devices Affected by Outside Electromagnetic Interference (EMI) from Cellular And Other Wireless Devices?" photocopied hearing statements, various witnesses, Oct. 5, 1994.
14. 47 U.S.C., sec. 610. FCC regulations on hearing aid compatibility can be found in 47 CFR, sec. 68.4.
15. Letter from Hon. Reed Hundt, Chairman of the FCC, to Sen. Bob Packwood, Chairman, Committee on Commerce, Science, and Transportation, Subcommittee on Communications, Apr. 12, 1995.
16. Jerry Hannifin, "Hazards Aloft," Time, Feb. 22, 1993, p. 61.
17. For example, verifiable cases of interference might resemble the following: when the flight crew notices something unusual occurring to the airplane, together with a passenger's use of an electronic device, they ask the passenger to turn the device off, and note whether the problem has disappeared. They then ask the passenger to turn the device back on to see if the interference occurs again. If it does, then this is an event to be explained. However, efforts to duplicate such effects on the ground have all been unsuccessful. John Sheehan, Pfaneuf Associates, CTIA consultant, chair of RTCA Special Committee 177, personal communication.
18. The RTCA, an advisory body to the FAA on electronic matters, is meeting to set standards for electronic device emissions in aircraft in the wake of concern about consumer electronic devices. It expects to issue its report on nonradio device interference in the spring of 1995.
19. Memorandum of Understanding between the FCC, NTIA, and the FAA, "Addressing Out-of-Band Emission Requirements for the Mobile-Satellite Service," effective Nov. 19, 1994.
20. Jerry Hannifin, "Hazards Aloft," Time, Feb. 22, 1993, p. 61.