Electrical characteristics of an electronic control device under a physiologic load: A brief report

Background: Law enforcement officers use electronic control devices (ECDs), such as the TASER X26 (TASER International, Inc., Scottsdale, AZ, USA), to control resisting subjects. Some of the debate on the safety of the devices has centered on the electrical characteristics of the devices. The electrical characteristics published by TASER International have historically based on discharges into a 400 Ω resistor. There are no studies that the authors are aware of that report the electrical characteristics under a physiologic load. In this study, we make an initial attempt to determine the electrical characteristics of the TASER X26 during a 5-second exposure in human volunteers. Methods: Subjects received an exposure to the dry, bare chest (top probe), and abdomen (bottom probe) with a standard TASER X26 in the probe deployment mode for 5 seconds. There were 10-11 pulse captures during the 5 seconds. Resistance was calculated using the sum of the absolute values of the instantaneous voltage measurements divided by the sum of the absolute values of the instantaneous current measurements (Ohm's Law). Results: For the eight subjects, the mean spread between top and bottom probes was 12.1 inches (30.7 cm). The mean resistance was 602.3 Ω, with a range of 470.5-691.4 Ω. The resistance decreased slightly over the 5-second discharge with a mean decrease of 8.0%. The mean rectified charge per pulse was 123.0 μC. The mean main phase charge per pulse was 110.5 μC. The mean pulse width was 126.9 μs. The mean voltage per pulse was 580.1 V. The mean current per pulse was 0.97 A. The average peak main phase voltage was 1899.2 V and the average peak main phase current was 3.10 A. Conclusions: The mean tissue resistance was 602.3 Ω in this study. There was a decrease in resistance of 8% over the 5-second exposure. This physiologic load is different than the 400 Ω laboratory load used historically by the manufacturer. We recommend future characterization of these devices use a physiologic load for reporting electrical characteristics. We also recommend that all the electrical characteristics be reported.