Ventricular fibrillation risk estimation for conducted electrical weapons: critical convolutions

Validity of the small swine model for human electrical safety risks

Small swine are the most common model now used for electrical safety studies. Because of the significant anatomical and electrophysiological differences and the effect of animal size on the ventricular fibrillation (VF) threshold, there are concerns that these differences may exaggerate the risks of electrical devices to humans. We chose, as an illustrative and relevant example, swine studies of the TASER® conducted electrical weapon (CEW) as it has numerous published VF studies. We reviewed the published electrical swine safety studies for CEWs and compared them to finite element modeling studies, electrical safety standards, and epidemiological experience from field usage. We also compared the body weights of the swine to those of law enforcement arrest-related deaths. Studies of small swine exaggerate the risks of CEWs to humans. This conclusion may be extrapolated to suggest that the use of small swine for electrical safety studies should be questioned in general.

Cardiac fibrillation risks with TASER conducted electrical weapons

The TASER(®) conducted electrical weapon (CEW) delivers electrical pulses that can temporarily incapacitate subjects. We analyzed the cardiac fibrillation risk with TASER CEWs. Our risk model accounted for realistic body mass index distributions, used a new model of effects of partial or oblique dart penetration and used recent epidemiological CEW statics.

Electrical safety of conducted electrical weapons relative to requirements of relevant electrical standards

INTRODUCTION

TASER(®) conducted electrical weapons (CEW) deliver electrical pulses that can inhibit a person's neuromuscular control or temporarily incapacitate. TASER X26, X26P, and X2 are among CEW models most frequently deployed by law enforcement agencies. The X2 CEW uses two cartridge bays while the X26 and X26P CEWs have only one. The TASER X26P CEW electronic output circuit design is equivalent to that of any one of the two TASER X2 outputs. The goal of this paper was to analyze the nominal electrical outputs of TASER X26, X26P, and X2 CEWs in reference to provisions of several international standards that specify safety requirements for electrical medical devices and electrical fences. Although these standards do not specifically mention CEWs, they are the closest electrical safety standards and hence give very relevant guidance.

METHODS

The outputs of two TASER X26 and two TASER X2 CEWs were measured and confirmed against manufacturer and other published specifications. The TASER X26, X26P, and X2 CEWs electrical output parameters were reviewed against relevant safety requirements of UL 69, IEC 60335-2-76 Ed 2.1, IEC 60479-1, IEC 60479-2, AS/NZS 60479.1, AS/NZS 60479.2 and IEC 60601-1. Prior reports on similar topics were reviewed as well.

RESULTS AND CONCLUSION

Our measurements and analyses confirmed that the nominal electrical outputs of TASER X26, X26P and X2 CEWs lie within safety bounds specified by relevant requirements of the above standards.

Defibrillation success rates for electrically-induced fibrillation: hair of the dog

Accidental electrocutions kill about 1000 individuals annually in the USA alone. There has not been a systematic review or modeling of elapsed time duration defibrillation success rates following electrically-induced VF. With such a model, there may be an opportunity to improve the outcomes for industrial electrocutions and further understand arrest-related-deaths where a TASER(®) electrical weapon was involved. We searched for MedLine indexed papers dealing with defibrillation success following electrically-induced VF with time durations of 1 minute or greater post VF induction. We found 10 studies covering a total of 191 experiments for defibrillation of electrically-induced VF for post-induction durations out to 16 minutes including 0-9 minutes of pre-shock chest compressions. The results were fitted to a logistic regression model. Total minutes of VF and use of pre-shock chest compressions were significant predictors of success (p < .00005 and p= .003 respectively). The number of minutes of chest compressions was not a predictor of success. With no compressions, the 90% confidence of successful defibrillation is reached at 6 minutes and the median time limit for success is 9.5 minutes. However, with pre-shock chest compressions, the modeled data suggest a 90% success rate at 10 minutes and a 50% rate at 14 minutes.1.