Pacemaker Phase II: Height of Separation Study Results
[Order Report]
[Executive Summary]
Phase I of the pacemaker study was a large- scale study designed to determine the significant factors and the extent of interaction between five wireless phone technologies (CDMA, PCS 1900, TDMA-11 Hz, TDMA-22 Hz and TDMA-50 Hz) and 29 pacemakers. The results were published in October 1996 in EMC Report 1996-3, In Vitro Study of the Interaction of Wireless Phones with Cardiac Pacemakers
Phase II of the pacemaker study builds upon the previous study by investigating the planar separation distance for those pacemaker-phone combinations that exhibited interaction. This resulted in testing combinations of six pacemakers with five phone technologies (TDMA-11 Hz, TDMA-22 Hz, TDMA-50 Hz, TDMA-217 Hz, and CDMA). The results of the Phase II study were published in June 1998.
The test methodology consisted of testing for interactions between the phone and pacemaker at various heights of separation from 0 inches to 3 inches. Testing was begun at the lowest level, and continued throughout subsequent levels until the interaction disappeared. The highest level with interaction was scanned in detail, and all interaction points were charted. A diagram illustrating the test setup for measuring the interaction distance is shown in Figure 1.
The researchers found that, for interaction to occur, the planar
separation between the base of the antenna and the pacemaker header had
to be significantly less than the Euclidean separation distance reported
in Phase I (Figure 2). This may provide a more realistic recommendation
for required minimum separation during phone use. Additionally, the
researchers found that the maximum fields were often concentrated over
the body of the phone rather than the antenna, as might be expected.
