Conducted Electrical Weapons Research Articles

Effectiveness of a New-Generation CEW in Human Subjects with a Goal-Directed Task

Conducted electrical weapons (CEWs) have been used by law enforcement agencies worldwide to control and restrain potentially violent persons. As new generations of these weapons are developed, effectiveness and safety need to be evaluated. The new TASER 10 uses an independently targeted probe scheme with floating polarities so that any two probes can form a connection. This is in contrast to older generation weapons, which used paired probes with fixed take-off angles. The expectation is with up to a maximum of 10 shots and independent targeting; the weapon will have a greater effectiveness. In this pilot study, we used our previously published, standardized methodology for measurement of CEW effectiveness on motivated human volunteers for several objectives: (1) to directly compare the effectiveness of the waveform on human subjects to an older generation weapon (the TASER 7), (2) to more broadly compare it to historical controls, and (3) to look at various probe configurations to determine their comparative effectiveness. The task at hand was to reach a suspended martial arts dummy 12 ft (3.65 m) away while being exposed (under power) to the electrical waveform of the TASER devices in various dart configurations. Several intervention groups were examined. We used video review with our standard methodology to rate goal achievement and limb capture. The results demonstrate that the TASER 10 has similar ability to induce neuromuscular incapacitation as the TASER 7. Additionally, the ability of the TASER 10 to place multiple darts on a specific target area to create the desired probe spread is a technological advantage over previous models. This, together with the floating polarity probes, promise to make the TASER 10 potentially more effective and flexible in the field.

Immobilisation efficacy of conducted electrical weapons on captive white-tailed deer

Context Wildlife emergencies (e.g. injured animals) often require capture or humane dispatch of animals to resolve the situation. Conducted electrical weapons (CEWs) have the potential to immobilise white-tailed deer (Odocoileus virginianus) for a short duration to avoid potential risks of extended immobilisation (e.g. chemical immobilisation) and increase safety for managers and the public during humane killing by gunshot. Aims To test rapid immobilisation with minimal long-term physiological consequences of CEW immobilisation of white-tailed deer. Methods We arranged five treatment groups of captive deer, including (1) chemical immobilisation with 5-s CEW exposure (n = 5), (2) chemical immobilisation with 15-s CEW exposure (n = 5), (3) 5-s CEW exposure with no chemical immobilisation (n = 10), (4) 15-s CEW exposure with no chemical immobilisation (n = 10) and (5) a control group with no chemical immobilisation or CEW exposure (n = 10). We conducted treatments 1 and 2 to determine short-term physiological effects of CEWs on deer, related to overall welfare. In treatment groups 1 and 2, we sedated deer to collect blood immediately before CEW exposure, and 2 days and 5 days post-exposure for serum biochemical analysis (to measure physiological markers of organ and tissue damage). We observed deer before, during and after treatments to evaluate potential behavioural changes. Key results All deer showed signs of muscle paralysis immediately after exposure to CEW and regained muscle control immediately after the exposure ended. Serum biochemistry results for treatment group 1 and 2 revealed significant increases in creatine kinase (CK) and aspartate aminotransferase (AST) 2 days post-treatment, before returning to pre-exposure concentrations by day 5-post-exposure, suggesting temporary myopathy. By 15-days post-exposure, deer that were only exposed to the CEW had 27 of 39 (69%) remotely fired probes still attached. No long-term behavioural or physiological changes were observed post-treatment. Conclusions Our findings suggest that for immobilisation of white-tailed deer, short-term exposure to a CEW to is a potential alternative to typical capture techniques and can provide sufficient immobilisation to approach and humanely kill deer by gunshot if necessary in wildlife emergencies. Implications As with all capture techniques, trainings and protocols should be developed to ensure the safety of personnel and animals during CEW exposures.

Conducted Electrical Weapon Fire Risk in the Presence of Supplemental Oxygen.

Conducted electrical weapons (CEWs) are nonlethal weapons used in tactical environments. Tactical EMS (TEMS) operators provide patient care in environments where CEWs are present. CEWs may produce a spark that can be a source of ignition. When supplemental oxygen is in use by a TEMS operator, the flammability risk from the CEW is unknown. We measured oxygen levels over 20 minutes in an enclosed space with a supplemental oxygen source maximally flowing. Measurements were taken at various distances from the oxygen source to establish baseline concentrations. These concentrations were replicated within a plexiglass box where a CEW was activated to create a sparking arc between probes embedded in a fresh swine shoulder (with skin intact). Various flammable materials, typically found in a patient care setting were used as potential fuel sources. The highest oxygen levels were achieved directly at the source. At 15cm from the source, the maximum oxygen concentration was 31.5%. Within the box, ignition was only achieved at oxygen concentrations greater than 45% and only when human hair was present as fuel. No ignition was achieved at oxygen levels below this regardless of the tested fuel present. Ignition from a CEW is possible at supplemental oxygen levels greater than 45% when human hair is present. In an enclosed space, oxygen concentration levels of 45% are only present within 15cm of a flush rate oxygen source. The likelihood of CEW-caused ignition in such settings with supplemental oxygen in use is extremely low.

The study on booster output characteristic for conducted electrical weapon applying on biological target and surrogates

The effectiveness and safety of conducted electrical weapons (CEWs) are closely related with their booster output characteristics. In this paper, the no-load of a police CEW, and the comparison of booster output characteristics between biological target and equivalent resistance under the same condition are measured, where the results verify the biological target cannot be simply replaced by an equivalent resistance, and a coupling model of resistance and capacity is necessary for next research. Considering the component similarity, a surrogate for biological target consisted of gelatin, water and different percentage of salt is prepared. On this basis, the equivalent load profiles for both biological target and salt gelatin surrogate targets, which obtains from the booster output voltage and current data, shows the transient pass for high-frequency signal and the cut-off for low-frequency signal simultaneously. Moreover, the little difference in high-pass equivalent resistance between biological target and gelatin surrogate target identify the gelatin surrogate is a suitable CEWs target.

Confusion between firearms and electrical weapons as a factor in police shootings.

Conducted electrical weapons (CEW) have risks including trauma associated with uncontrolled falls, probes penetrating the eye, and fume ignition. A lesser-known risk is weapon-confusion error with officers mistakenly discharging their firearm when they intended to deploy their electrical weapon. We searched for incidents of possible weapon confusion with the TASER® brand CEWs via open-source media, litigation filings, and a survey of CEW law enforcement master instructors. We found 19 incidents of possible CEW weapon confusion in law enforcement field uses from January 2001 to April 2021. We eliminated a case as not meeting our criteria for probable weapons confusion leaving 18 cases, thus giving a demonstrated CEW discharge risk of 3.9 per million with confidence limits (2.4-6.2 per million) by Wilson score interval. Ipsilateral carry of the weapons was historically correlated with increased risk vs. contralateral carry. Officer gender was not a predictor of weapon confusion. The psychological issues behind weapon confusion under stress are discussed. The concurrent carry of electrical weapons and firearms presents a very small but real risk of injury and death from confusion between an electrical weapon and a firearm.

Estimation of Physiological Impedance from Neuromuscular Pulse Data.

A Conducted Electrical Weapon (CEW) deploys 2, or more, probes to conduct current via the body to induce motor-nerve mediated muscle contractions, but the inter-probe resistances can vary and this can affect charge delivery. For this reason, newer generation CEWs such as the TASER® X3, X2 and X26P models have feed-forward control circuits to keep the delivered charge constant regardless of impedance. Our main goal was to explore the load limits for this "charge metering" system. A secondary goal was to evaluate the reliability of the "Pulse Log" stored data to estimate the load resistance. We tested 10 units each of the X2 (double shot), X26P, and X26P+ (single-shot) CEW models. We used non-inductive high-voltage resistor assemblies of 50, 200, 400, 600, 1k, 2.5k, 3.5k, 5k, and 10k Ω, a shorted output (nominal 0 Ω), and arcing open-circuits. The Pulse Log data were downloaded to provide the charge value and stimulation and arc voltages for each of the pulses in a 5 s standard discharge cycle. The average reported raw charge was 65.4 ± 0.2 µC for load resistances < 1 kΩ consistent with specifications for the operation of the feed-forward design. At load resistances ≥ 1 kΩ, the raw charge decreased with increasing load values. Analyses of the Pulse Logs, using a 2-piece multiple regression model, were used to predict all resistances. For the resistance range of 0 - 1 kΩ the average error was 53 Ω; for 1 kΩ - 10 kΩ it was 16%. Muzzle arcing can be detected with a model combining parameter variability and arcing voltage. The X2, X26P, and X26P+ electrical weapons deliver an average charge of 65 µC with a load resistance < 1 kΩ. For loads ≥ 1 kΩ, the metered charge decreased with increasing loads. The stored pulse-log data for the delivered charge and arc voltage allowed for methodologically-reliable forensic analysis of the load resistance with useful accuracy.

Medical Care in a Police Intervention with Conducted Electrical Weapons: Zaragoza (Spain) Fire Department Protocol.

In the last decade, conducted electrical weapons (CEWs) have become a new tool for law enforcement agencies as an alternative to firearms. They provide security in the intervention for both the police and the citizen and try to cause the least possible harm to the subject to immobilize.The health care providers who perform in joint actions with the police in which CEWs are used should be aware of how they work, risk groups, as well as the most frequent clinical effects associated with the application of electrical discharge, and the complications that can be produced according to the area of impact of the electrodes.For this purpose, the current medical literature was reviewed by consulting the main health care sciences database (PubMed) to determine the medical measures to be taken before, during, and after the use of these weapons. Also presented and shared is the Zaragoza (Spain) Fire Department protocol.

Human Health Risks of Conducted Electrical Weapon Exposure

Conducted electrical weapons (CEWs) are used broadly as a less-lethal force option for police officers. However, there is no clear picture of the possible health risks in humans on the basis of rigorously assessed scientific evidence from the international peer-reviewed literature. To synthesize and systematically evaluate the strength of published evidence for an association between exposure to different models of CEWs and adverse acute as well as chronic conditions. Following a preregistered review protocol, the literature search strategy was based on a search of reviews published between January 1, 2000, and April 24, 2020, of PubMed, MEDLINE, EMBASE, Web of Science, PsycINFO, and Cochrane Library, as well as relevant online databases and bibliographic sources, such as reference sections of recent publications. The identified studies were independently assessed in terms of scope, relevance, methodologic bias, and quality. Peer-reviewed publications of human studies were included, using original data and with a focus on the use of taser CEWs in the context of law enforcement. Eligible studies examined clearly defined health outcomes as dependent variables following exposure to a CEW. The review followed the relevant sections of the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline. A meta-analysis could not be conducted. Of the 1081 unique records screened, 33 relevant studies were identified, all of them of experimental design and conducted in the US. Eleven studies had a low risk of bias and 22 had a higher bias risk. Studies focused on outcomes such as physiologic stress responses, heart rate, blood pressure, arrhythmias, or cognitive performance. Independently of bias risk, the studies reported few or no acute health problems, apart from the wounds caused by the darts. Furthermore, no long-term outcomes were studied. Most of the studies were performed on healthy, physically fit individuals (eg, police officers) in a controlled setting, with short exposure duration (5 seconds). Half of the studies, mainly those with a higher risk of bias, were at least partly funded by the manufacturer. Based on the findings of the reviewed studies, the risk for adverse health outcomes due to CEW exposure can be currently estimated as low. However, most of the reviewed studies had methodologic limitations. Considering that recruited participants were not representative of the population that usually encounters a CEW deployment, it is not possible to draw conclusions regarding exposure outcomes in potentially vulnerable populations or high-risk groups, such as those under the influence of substances.

A comparison of three conducted electrical weapons in a surrogate swine cardiac safety model

We used a previously described methodology in a swine model to compare the relative cardiac safety of the Axon T7 Conducted Electrical Weapon (CEW), released in October of 2018, to two prior generations of Axon CEWs to include the X2 and the X26E. A total of 5 swine (252 total CEW exposures) were tested by alternating the three weapons at each chest exposure location. Our testing, using systemic hypotension as the quantitative surrogate for cardiac capture, demonstrated that the T7 and X2 were not statistically different. Both were superior, in terms of reduced hypotension during exposure, to the X26E. This study is important as it demonstrates that the newly released weapon is non-inferior to the X2 and superior to the X26E using this surrogate safety model. It is also important because it is the first study to examine the cardiac effects of simultaneous multi-bay exposures. Our prior study compared the X2 to the X26E but examined only single bay exposures from the X2. Lastly, we feel we have improved the methodology for studying the comparative cardiac effects of CEWs.

Electrical weapons and rhabdomyolysis.

It has been suggested that an application of a conducted electrical weapon (CEW) might cause muscle injury such as rhabdomyolysis and an acute inflammatory response. We explored this hypothesis by testing the effects of electrical weapons on circulating markers of inflammation and muscle damage. In a prospective study, 29 volunteers received a full-trunk 5-s TASER® X26(E) CEW exposure. Venous blood samples were taken before, 5min after, and at 24h following the discharge. We tested for changes in serum levels of C-reactive protein (CRP), alkaline phosphatase (ALP), myoglobin, albumin, globulin, albumin/globulin ratio, aspartate and alanine aminotransferase, creatine kinase, total protein, bilirubin, and lactic acid dehydrogenase. Uncorrected CRP and myoglobin levels were lower in the immediate post exposure period (CRP levels 1.44 ± 1.39 v 1.43 ± 1.32mg/L; p = 0.046 and myoglobin 36.8 ± 11.9 v 36.1 ± 13.9μg/L; p = 0.0019) but these changes were not significant after correction for multiple comparisons. There were no changes in other biomarkers. At 24h, CRP levels had decreased by 30% to 1.01 ± 0.80mg/L (p = 0.001 from baseline). ALP was unchanged immediately after the CEW application but was reduced by 5% from baseline (66.2 ± 16.1 to 62.7 ± 16.1IU/L; p = 0.0003) at 24h. No other biomarkers were different from baseline at 24h. A full-trunk electrical weapon exposure did not lead to clinically significant changes in the acute phase protein levels or changes in measures of muscle cellular injury. We found no biomarker evidence of rhabdomyolysis.

A comparative study of conducted electrical weapon incapacitation during a goal-directed task

Conducted electrical weapons (CEW) are ubiquitous in law enforcement given their unique ability to physically incapacitate violently resisting subjects. Early use of animal models to study CEW incapacitation effectiveness (e.g. porcine model with 4-limb strain gauges) proved to be poorly predictive of human incapacitation effectiveness. In a previously published human study, we developed a methodology for the prospective assessment of the incapacitation effectiveness of CEWs in highly motivated human subjects. Here we use this methodology in Part 1 to compare the incapacitation effectiveness of the newly released Axon® (formerly TASER® International) T(ASER) 7 to the TASER X26E, the "gold standard", and the TASER X2, a current model. The T7 has a new "adaptive cross-connect" technology that may improve incapacitation effectiveness in the scenario of small spreads between probe pairs, a common cause of weapon "failure" in the field. In Part 2, we use our methodology to test the functionality of the T7 cross-connect technology by comparing different bay and probe configurations. This is the first published study in the literature comparing different CEW models using this human model. For Part 1, 29 subjects completed the study and had data available for analysis. For Part 2, 21 subjects completed the study and had data available for analysis. The subjects were motivated to complete the task of reaching a suspended martial arts dummy 3.4m (11ft) away while being exposed "under power" to the CEW. In Part 1, subjects were assigned to 1 of 6 groups with probe spreads of 10, 20, and 30cm (4, 8, 12 in). Subjects were exposed to a "control" CEW (either the X2 or X26E) and the T7 on alternating sides. Exposures with the X2 and T7 included 2 bay-exposures. In Part 2, 21 subjects were assigned to 1 of 5 groups of different T7 bay and probe configurations all with a theoretical effective spread of 30cm (12 in). Subjects were rated on their progress towards successfully reaching the dummy and on the extent of limb incapacitation using a quasi-blinded expert-observer scoring panel based on high-speed video review. In Part 1, all CEW models achieved maximal or near-maximal subject control with the 30cm probe spread. With probe spreads of 10 and 20cm the pooled data showed the T7 to be superior to the X2 for goal achievement (p < 0.001) and limb incapacitation (p = 0.002) mostly driven by differences seen with the 10cm spread (2-bay exposures). The T7 was non-inferior to the X26E. In Part 2, there was no statistical significance between the limb capture scores, but there was a statistically significant difference in goal scores. The results overall validate that the T7 CEW cross-connect feature performed as expected. The T7 adaptive cross-connect feature with two simultaneous deployed probe pairs demonstrated a significant improvement in incapacitation effectiveness compared to the current X2 CEW with two simultaneously deployed probe pairs. Small probe spreads are a common reason for limited incapacitation effectiveness in the field and this study suggests the T7 may offer an improvement in this scenario. The T7, with single-bay exposures, was non-inferior to the single-bay X26E.

Electrical weapons, hematocytes, and ischemic cardiovascular accidents

BackgroundThere have been case reports following the use of a conducted electrical weapon (CEW) suggesting that these devices might affect coagulation or thrombosis in at-risk individuals. The aim of this manuscript therefore is firstly to explore this hypothesis by reviewing each of these cases and secondly to report the results of a prospective study exploring a priori the effects of electrical weapons on hematocytes in a group of human volunteers. MethodsFirst, we systematically reviewed all cases of adverse outcomes following CEW discharge that could be due to an effect on coagulation or thrombosis, with particular focus on the clinical scenario and its relationship with the weapon discharge. Second, we assessed hematocyte levels in venous blood from 29 volunteers before, 5 min after, and 24 h after receiving a full-trunk 5-s TASER® X26(E) CEW exposure. ResultsFollowing extensive review of the literature, we found 3 relevant case reports of possible vascular thromboembolic clinical events after CEW exposure, specifically a case of ischemic stroke, and 2 cases of ST-segment elevation myocardial infarctions. Review of these published cases failed to establish a plausible linkage to the CEW beyond a temporal association with significant emotional and physiological stress from a violent struggle.Our prospective study of biomarker change following CEW discharge revealed acutely increased values for WBC (white blood cells), specifically lymphocytes and monocytes, and a raised platelet count. Neutrophil levels decreased as a percentage of WBC. While these changes were statistically significant at 5 min, all results remained within established reference ranges. At 24 h, all values had returned to baseline except total WBC which decreased to slightly below baseline but was still within the normal reference range. ConclusionsA review of clinical cases, of ischemic or thrombotic events revealed no direct association with the CEW discharge. A full-trunk electrical weapon exposure did not lead to hematocyte changes beyond normal clinically expected variations in similar acute response scenarios. The case report and biomarker data do not support the hypothesis that a CEW discharge is associated with changes likely to promote coagulation or thrombus formation.

The physiologic effects of a new generation conducted electrical weapon on human volunteers at rest.

Axon Enterprise, Inc. (Axon) released its newest generation conducted electrical weapon (CEW), the T7, in October 2018. In order to compare the effects of this new CEW to prior generations, we used our previously described methodology to study the physiologic effects of CEWs on human volunteers at rest. This was a prospective, observational study of human subjects consisting of two parts. Part 1 was testing a single cartridge (2-probe) exposure. Subjects received a 10-s exposure from the T7 to the back with a 30cm (12in.) spread between the two probes. Part 2 was testing a simultaneous two-cartridge (4-probe) exposure. Subjects received a 10-s exposure from the T7 to the back with two cartridges with a 10cm (4in.) spread between each probe pair. The probe pairs were arranged cephalad to caudal such that the distance between the top probe of the first cartridge and the bottom probe of the second cartridge was 30cm (12in.). Vital signs were measured immediately before and after the exposure. Continuous spirometry was performed. ECG monitoring was performed immediately before and after the exposure. Venous pH, lactate, potassium, CK, catecholamines, and troponin were measured before and immediately after the exposure, at 1-h post-exposure, and again at 24h. 11 subjects completed part 1 of the study. 9 subjects completed part 2 of the study. No subjects had a dysrhythmia or morphology change in the surface ECG. There were no statistical changes in vital signs pre- and post-exposure. While subjects did not have a statistical change in spirometry parameters pre-exposure to exposure except for a small drop in PETCO2, there was an increase in minute ventilation after the exposure that could have several explanations. A similar pattern was seen with prior generation weapons. No subject had elevated troponin levels. Other blood parameters including venous pH, lactate, potassium, CK, and catecholamines had changes similar to prior generation weapons. Comparison of the data for the single-cartridge exposures against the simultaneous two-cartridge exposures yielded no difference in vital signs, but the minute ventilation was higher for the two-cartridge exposures. The blood data, where there was a difference, was mixed. In our study, the physiologic effects of the Axon T7 are modest, consistent with the electrically-induced motor nerve-driven muscle contraction, and were similar to prior generation weapons.

Tasing the Constitution: Conducted Electrical Weapons, Other Forceful Arrest Means, and the Validity of Subsequent Constitutional Rights Waivers

Conducted electrical weapons (CEWs) — the most famous and widely used of which are offered under the TASER brand — are ubiquitous tools of law enforcement, carried by the vast majority of law enforcement officers and routinely deployed. These devices subdue targets by coursing electric current through their bodies, thereby causing individuals to collapse as their muscles involuntarily contract. Yet this method of operation has raised concerns—voiced by researchers, advocates, and criminal defendants alike — that CEWs influence cognitive capacity in addition to muscle function as electric current potentially transits through the brain via the central nervous system. In the context of an arrest, this implicates criminal suspects’ ability to understand Miranda warnings given by officers and to competently waive their constitutional rights against self-incrimination and to counsel. Some have gone so far as to recommend a mandated delay between when suspects are tased and when officers may administer Miranda warnings in order to protect individuals’ rights. Intimate understandings of the law of Miranda v. Arizona and the true effects of CEWs on cognitive capacity are critical for determining the prudence of this recommendation, and have broader implications for the criminal justice system. This Article is the first to conduct a thorough survey and analysis of the law of Miranda with regard to how courts determine whether individuals’ waivers of their constitutional rights following Miranda warnings are knowing, intelligent, and voluntary. Ultimately, cognitive capacity is an important factor, but, in examining this faculty, courts generally rely most heavily on subjective indicia of mental acuity manifested at the time Miranda warnings were administered — e.g., reasoning ability, tone, bodily movements, and temperament. Objective indicia of mental acuity — i.e., those shown through empirical research to signal cognitive ability, such as age, education, intelligence, and blood alcohol content — are routinely treated as less valuable than subjective indicia, particularly when the two are in opposition. This presents a high bar for empirical research on the cognitive effects of CEWs to scale in order to meaningfully influence court determinations of the legitimacy of rights waivers. This Article is also the first to conduct a comprehensive survey and examination of the literature addressing the cognitive effects of CEWs and compare these effects to those of other forceful arrest methods. Studies reveal that, rather than having a unique effect on cognition through some interaction between electric current and the brain, CEWs actually appear to impact mental faculties through a general stress effect, which other forceful methods of arrest have as well — e.g., physical altercation, police dog attack, and pepper spray. Therefore, an exceptional rule requiring a delay in administering Miranda warnings to suspects subject to CEWs does not seem appropriate. Nevertheless, the literature does show forceful arrest methods meaningfully affecting individual mental acuity. While more research is necessary to more finely deduce the extent of these impacts, they appear to be such that courts should consider a forceful arrest close enough in time to the administration of a Miranda warning to be a negative factor in assessing defendants’ competence to waive their rights, similar to evidence indicating low intelligence or intoxication at the time of waiver.

Benefits, Risks, and Myths of TASER® Handheld Electrical Weapons

Handheld conducted electrical weapons (CEWs) have been used 3.9 million times in the field in 107 countries. Prospective studies (including over 40 k uses of force) find a 65% reduction in subject injuries versus batons, manual control, and “pepper” spray. There is a 2/3 reduction in fatal shootings when CEW usage is not overly restricted. USA-derived data suggest that the temporal subject fatality rate with resistant arrest is ≈ 1:1000 without a CEW and ≈ 1:3000 with the CEW. UK data suggest 85% compliance with simply the threat of a CEW. There have been 18 deaths from falls (16 brain injuries and 2 cervical fractures) and 8 deaths from fume ignition. These 26 deaths provide a fatality risk of 6.7 per million [95% CI 4.5–9.8]. There are 20 cases of unilateral blindness from a probe eye penetration. There were also 4 cases of non-fatal major burns and 1 of permanent brain damage from a fall. These 25 injuries provide a risk of 6.4 per million [(95% CI 4.3–9.5]. The risk of electrocution is very low since present CEWs satisfy the IEC 60335 electric fence limit of 2.5 W and the ANSI-CPLSO-17 limits of 125 μC per pulse with a normalized aggregate current of 2.2 mA. Arrest-related death anecdotes alleging an electrocution all fail several diagnostic tests for an electrocution. While reducing subject injury and death by about 2/3, CEW usage has an overall major complication rate of 13.1 per million field uses [95% CI 9.9–17.2], primarily from falls, fires, and eye injuries.

Penetration Depths of Conducted Electrical Weapon Probes Into Human Skull Phantoms.

Occasional case reports have described isolated cases of conducted electrical weapon (CEW) probes piercing the human skull. In an experimental setting, we examined whether these cases were just unfortunate incidents, how deeply such probes can pierce the skull, and whether firing distance and CEW probe type play a role in the skull-piercing capability.We fired 5 different CEW cartridges (XP 10.6 m, XP 7.6 m, smart 10.6 m, smart 7.6 m, and smart probe 7.6 m) from 4 different distances (0.5, 1, 2, and 4 m) at head phantoms made of either 5- or 7-mm-thick polyurethane spheres covered with a thin layer of gelatine and buckskin. The piercing depths were recorded by computed tomographic scanning.All tested cartridges managed to pierce the head phantoms. Piercing depths of up to 6.6 mm in the 5-mm heads and depths of almost 5 mm in the 7-mm heads were recorded. Deepest piercing depths were attained with firing distances of 2 m or less.Our results showed that all tested CEW probes are capable of piercing the skull and that shorter firing distances tend to lead to deeper piercing depths.

Emergency Medical Services Experience With Barb Removal After Taser Use By Law Enforcement: A Descriptive National Study.

Conducted electrical weapons (CEWs), including Thomas A. Swift Electric Rifles (TASERs), are increasingly used by law enforcement officers (LEOs) in the US and world-wide. Little is known about the experience of Emergency Medical Service (EMS) providers with these incidents. This study describes EMS encounters with documented TASER use and barb removal, characteristics of resulting injuries, and treatment provided. This retrospective study used five combined, consecutive National Emergency Medical Services Information System (NEMSIS; Salt Lake City, Utah USA) public-release datasets (2011-2015). All EMS activations with documented TASER barb removal were included. Descriptive analyses were carried out. The study included 648 EMS activations with documented TASER barb removal, yielding a prevalence rate of 4.55 per 1,000,000 EMS activations. Patients had a mean age of 35.9 years (SD=18.2). The majority were males (80.2%) and mainly white (71.3%). Included EMS activations were mostly in urban or suburban areas (78.3%). Over one-half received Advanced Life Support (ALS)-level of service (58.2%). The most common chief complaint reported by dispatch were burns (29.9%), followed by traumatic injury (16.1%). Patients had pain (45.6%) or wound (17.2%) as a primary symptom, with most having possible injury (77.8%). Reported causes of injury were mainly fire and flames (29.8%) or excessive heat (16.7%). The provider's primary impressions were traumatic injury (66.3%) and behavioral/psychiatric disorder (16.8%). Only one cardiac arrest (0.2%) was reported. Over one-half of activations resulted in patient transports (56.3%), mainly to a hospital (91.2%). These encounters required routine EMS care (procedures and medications). An increase in the prevalence of EMS activations with documented TASER barb removal over the study period was not significant (P=.27). At present, EMS activations with documented TASER barb removal are rare. Routine care by EMS is expected, and life-threatening emergencies are not common. All EMS providers should be familiar with local policies and procedures related to TASER use and barb removal.El SayedM, El TawilC, TamimH, MailhacA, MannNC. Emergency Medical Services experience with barb removal after TASER use by law enforcement: a descriptive national study. Prehosp Disaster Med. 2019;34(1):38-45.

Increased Hematocrit Due to Electrical-Waveform Exposures in Splenectomized Sus scrofa.

In laboratory studies of the pig Sus scrofa, hematocrit has consistently increased after conducted-electrical-weapon (CEW) exposures, possibly due to contraction of the spleen. Splenectomized animals and intact sham control animals were exposed, each for 30 sec, to a benchtop-produced electrical waveform of net charge levels similar to those of some CEWs. Changes in the blood were compared statistically. Hematocrit increased significantly in both splenectomized and sham animals. There were no significant main-effect differences between values of hematocrit from the two groups. There were, however, significant interactive effects of time and splenectomy for hematocrit, red blood cell count, and hemoglobin. After peak values were reached for these variables, values returned toward baseline levels more slowly in splenectomized animals. This may have been due to the lack of a spleen to sequester red blood cells (thereby resulting in more cells remaining in the general circulation), unlike sham animals with intact spleens.

Electrical weapons and excited delirium: shocks, stress, and serum serotonin.

It has been suggested that a CEW (conducted electrical weapon) exposure could elicit a stress response that could cause ExDS (excited delirium syndrome). There are some parallels between the signs of ExDS and serotonin syndrome (SS). Electroconvulsive therapy raises serotonin levels and therefore provides a plausible link between CEW applications and elevated serotonin levels. This study was designed to determine whether a CEW exposure elevates serum serotonin. A total of 31 police academy cadets were exposed to a very broad-spread 5-s CEW stimulus from a TASER brand X26 CEW. Blood was drawn before and after the exposure and at 24h post exposure to measure serum serotonin levels. Lactic acid and cortisol levels were also compared. Median serum serotonin levels were 30 IQR (21,46), 36 IQR (22,50), and 32 IQR (21,45) ng/mL before exposure, after exposure, and 24h after exposure (NS by pooled comparisons). The increase from baseline to post-test serotonin (∆ median = +6, ∆ mean = +2.7) ng/mL was not significant by a paired T-test (p = .29) but was significant by the Wilcoxon signed-rank test (p = .037). The increase to post-test log serotonin was not significant by a paired T-test (p = .13) but was significant by the Wilcoxon test (p = .049). All serotonin levels remained within the normal reference range of 0-200ng/mL. Post-hoc analysis demonstrated that the study was powered to detect a ½ SD change, in log serotonin, with a 90% likelihood. With a very-broad electrode spread, CEW exposure did not significantly raise serum serotonin levels.

Electrical Weapon Charge Delivery With Arcing.

Human electronic control with the Conducted Electrical Weapon (CEW) has gained widespread acceptance as the preferred law enforcement force option technology due to its dramatic injury and fatal shooting reduction. However, with bulky or baggy clothing, a CEW probe may fail to make direct skin contact and thus arcing is critical to complete the circuit. The goal of the study was to evaluate the ability of modern CEWs to deliver their pulse charges across typical required arcing distances. Popular TASER® CEW models X26E (openloop output), and the X2 and X26P (with closed-loop outputs) were activated using a cartridge connected to a custom polymer air-gap fixture. For each model 5 units were tested. The raw and normalized charge delivery were evaluated according to ANSI-CPLSO-17. All 5 units of each model satisfied ANSICPLSO-17 even at maximum arcing length. The X26P CEW had the greatest arcing gap capability. The stabilized closed-loop charge output feedback of modern electrical weapons (X2 and X26P CEWs) provides a significantly improved output consistency under arcing conditions. With arc lengths of 10-20 mm per probe, the X2 CEW normalized output charge exceeds that of some units of the older higher output X26E CEW model.