This article examines the dart-to-heart distance, the maximum distance between the heart and a model Taser stimulation dart, at which a Taser can directly cause ventricular fibrillation (VF) in pigs.
Electromuscular incapacitating devices (EMDs), such as Tasers, deliver high current, short duration pulses that cause muscular contractions and temporarily incapacitate the human subject. Some reports suggest that EMDs can kill. To help answer the question, "Can the EMD directly cause ventricular fibrillation (VF)?," ten tests were conducted to measure the dart-to-heart distance that causes VF in anesthetized pigs [mass=64 kgplusmn6.67 standard deviation (SD)] for the most common X26 Taser.
The dart-to-heart distance that caused VF was 17 mmplusmn6.48 (SD) for the first VF event and 13.7 mmplusmn6.79 (SD) for the average of the successive VF events. The result shows that when the stimulation dart is close enough to the heart, X26 Taser current will directly trigger VF in pigs. Echocardiography of erect humans shows skin-to-heart distances from 10 to 57 mm (dart-to-heart distances of 1-48 mm). These results suggest that the probability of a dart on the body landing in 1 cm 2 over the ventricle and causing VF is 0.000172 (Publisher abstract provided)