There is still an ongoing debate whether or not electronic stun devices (ESDs) induce cardiac fibrillation. To assess the ventricular fibrillation risk of law enforcing electronic control devices, quantitative estimates of cardiac electric current densities induced by delivered electric pulses are essential. Numerical simulations were performed with the finite integration technique and the anatomical model of a standardized European man (NORMAN) segmented into 2 mm voxels and 35 different tissues. The load-dependent delivery of TASER X-26 pulses has been taken into account. Cardiac exposure to electric current densities of vertically and horizontally aligned dart electrodes was quantified and different hit scenarios compared. Since fibrillation thresholds critically depend on exposed volume, the provided quantitative data are essential for risk assessment. The maximum cardiac rms current densities amounted to 7730 A m(-2). Such high current densities and exposed cardiac volumes do not exclude ventricular fibrillation.

The prevalence of pacemaker patients among the general population and of conducted energy devices (CED) for law enforcement and self-defence is increasing. Consequently, the question whether cardiac pacemaker (CPM) patients are on particular risk becomes increasingly important. The risk of Taser X26 electric interference with implanted CPM has been investigated by numerical simulation at MRI-based anatomical models of CPM patients with devices implanted at conventional sites (left pectoral, right pectoral and abdominal) and with the monopolar CPM electrode placed at the ventricular apex. In spite of 10 fold higher peak voltages the different coupling conditions make Taser-induced CPM interference voltages lower than those caused by external cardiac defibrillators. It is shown that electric interference considerably depends on ECD electrode orientation. The most unfavourable conditions are encountered with ECD electrodes aligned with the line from the CPM electrode tip to CPM can (EPC line). It could be shown that worst case interference voltages of monopolar pacemakers of any kind of implantation remain below the pulse immunity level as defined in safety standards of implantable cardiac pacemakers and of cardioverter defibrillators. However, interference voltages exceed CPM sensing thresholds. Therefore, capturing should be expected at Taser X26 contact mode application at any position at the upper part of the body including the abdomen, both at frontal and dorsal positions.

To investigate electromagnetic interference (EMI) of electromagnetic fields (EMF) from electronic article surveillance (EAS) systems with electronic implants numerical anatomical models of pacemaker patients were generated accounting for different implantation sites (left pectoral, right pectoral and abdominal) and body size. Induced interference voltages were calculated with a software package applying the Finite Integration Technique and analysed in dependence on frequency. Results were referred to reported maximum magnetic fields levels measured at EAS systems in the ELF, IF and RF range. With reference to electromagnetic immunity requirements of safety standards of implanted cardiac pacemakers and defibrillators, the numerical analysis showed that the relevance of interference depends on the applied EMF frequency. At EAS systems operating in the RF range, EMI and consequential inadequate pacing is rare but cannot be ruled out. The probability of such events increases at EAS systems in the IF range and even more in the ELF range. Since interference is encountered already at yet existing systems, the situation would be worse if future systems would further increase their emissions by making use of the elevated reference levels recommended in updated exposure guidelines.

A new type of planar subarray composed of rectangular dielectric resonators fed by a microstrip‐line / aperture combination has been devised and investigated. Good performance has been achieved, including a 10‐dB impedance bandwidth of 18% and excellent radiation patterns. Results for impedance bandwidth, radiation patterns, and mutual coupling effects are presented. © 1994 John Wiley & Sons, Inc.

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