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Effects of an increased air gap on the in vitro interaction of wireless phones with cardiac pacemakers.

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Grant FH, Schlegel RE, · 2000

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Moving a wireless phone just 2 cm further from a pacemaker eliminates half of electromagnetic interference problems.

Plain English Summary

Summary written for general audiences

Researchers tested how wireless phones interfere with cardiac pacemakers at different distances, using laboratory conditions that mimicked the human torso. They found that even small increases in distance dramatically reduced interference - when phones were moved from 1 cm to 2 cm away from the pacemaker, half of the problematic interactions disappeared. The study revealed that keeping phones just 8.6 cm away perpendicular to the chest provides much better protection than the standard 15 cm recommendation measured horizontally.

Why This Matters

This research provides crucial practical guidance for the millions of Americans with pacemakers who rely on wireless phones daily. The science demonstrates that electromagnetic interference between phones and pacemakers follows predictable patterns based on distance and positioning - knowledge that can literally be life-saving. What makes this study particularly valuable is its real-world applicability: it tested multiple phone technologies under worst-case laboratory conditions, giving us confidence in the safety margins. The finding that perpendicular distance matters more than horizontal distance challenges current safety guidelines and suggests that pacemaker patients may have been given overly restrictive advice. Put simply, understanding the physics of electromagnetic coupling allows for more precise, practical recommendations that don't unnecessarily limit patients' communication options while still ensuring their safety.

Exposure Information

A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 11 Hz - 217 Hz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 11 Hz - 217 HzPower lines50/60 HzCell phones~1 GHzWiFi2.4 GHz5G mm28 GHzLogarithmic scale

Specific exposure levels were not quantified in this study. The study examined exposure from: TDMA-11 Hz, TDMA-22 Hz, TDMA-50 Hz, and TDMA-217 Hz

Study Details

The aim of this study is to investigate Effects of an increased air gap on the in vitro interaction of wireless phones with cardiac pacemakers.

Twenty pacemaker-phone combinations involving 6 pacemakers and 9 phones were evaluated in vitro unde...

Small increases in the perpendicular air gap between the phone and the saline surface resulted in a ...

The results have implications for those making recommendations to pacemaker patients who may be unaware of this distinction

Cite This Study
Grant FH, Schlegel RE, (2000). Effects of an increased air gap on the in vitro interaction of wireless phones with cardiac pacemakers. Bioelectromagnetics 21(7):485-490, 2000.
Show BibTeX
@article{fh_2000_effects_of_an_increased_2122,
  author = {Grant FH and Schlegel RE and},
  title = {Effects of an increased air gap on the in vitro interaction of wireless phones with cardiac pacemakers.},
  year = {2000},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/11015112/},
}
PubMed: 11015112

Cited By (13 papers)

Quick Questions About This Study

Research shows keeping phones 8.6 cm perpendicular from your chest provides excellent protection for pacemaker patients. This distance eliminated 99.93% of interference problems in laboratory testing, proving much more effective than the standard 15 cm horizontal recommendation.
Yes, doubling the distance from 1cm to 2cm eliminated approximately half of all pacemaker interference problems with TDMA wireless phones. This dramatic improvement demonstrates how even small increases in separation distance significantly enhance pacemaker safety.
Perpendicular positioning requires only 8.6cm separation versus 19cm horizontally because of how electromagnetic fields couple with the body. The perpendicular approach provides superior protection by taking advantage of the phone antenna's directional radiation pattern.
TDMA phone interference with pacemakers dropped to just 1.4% when phones were positioned 7.4cm away perpendicular to the chest. This represents a massive reduction from the interference rates observed at closer distances in laboratory testing.
Yes, all tested TDMA frequencies (11Hz, 22Hz, 50Hz, and 217Hz) showed potential for pacemaker interference in close proximity. However, the interference dramatically decreased with distance regardless of the specific TDMA frequency used by the wireless phone.