TASER Electronic Control Devices Review Of Safety Literature

For the risk of delivering a pulse into the vulnerable period of the cardiac cycle
the charge required is about 100–130 times that which the TASER X26 delivers.
The TASER M26 safety margin was calculated at an even higher range of 118-
153:1.
Concerning the risk for the delivery of “continuous” current there is a safety margin
of 74:1-89:1 for the TASER X26 and TASER M26.
These above analyses are based on currents applied down the trunk typically
from a leg to an arm. Currents passing from arm to arm have considerably higher
safety margins. With a barb tip close to touching the heart, the margins are lower
as will be discussed later. In drive-stun mode the safety margin is significantly
increased.
2.4 Computer Modeling Results
Extensive computer modeling has been performed to analyze the flow of the
ECD current in the human body by Dorin Panescu, a recognized authority in finite
element analysis of biological current flow. 43-45 The models calculated
strength-duration thresholds for heart cell excitation and VF induction. Finite element
modeling is used to compute current density in the heart for worst-case
TASER electrode placement. The model predicts a maximum TASER current
density of 0.27 mA/cm 2 in the heart. Numerically simulated TASER ECD current
density in the heart is about 1/2 the threshold for cardiac myocyte excitation and
more than 500 times lower than the threshold required for inducing VF. Thus
TASER devices do not generate currents in the heart that are high enough to excite
myocytes or trigger VF. Other modeling studies have been published as
well. 46,47
2.5 Animal Study Results
Sensitive Swine
Swine are more sensitive to electrical induction of arrhythmias than are other
mammals. 39 In dogs and humans the Purkinje fibers (the “nerves” in the heart
that carry the initial excitation signal) are confined to a very thin endocardial
layer. 48 In pigs the fibers cross the entire ventricular wall. 40 Thus activation in
swine proceeds from the epicardium to the endocardium while in dogs and human
it proceeds in the reverse direction. 49 Thus, swine are much more sensitive
to external electrical currents. Swine hearts are literally wired inside out compared
to humans. For example, high frequency cardiac ablation is performed on
hundreds of human patients every day without the induction of VF. However, the
exact same procedure will typically lead to VF in a swine. 50
Thus swine provide an extremely conservative test for cardiac safety of ECDs. If
an ECD fails to induce VF in a swine with conditions similar to law enforcement
or self-defense field usage, this implies a high degree of safety. If however, one
32