Blood factors of Sus scrofa following a series of three TASER electronic control device exposures

In a previous study, 18 repeated exposures of anaesthetized swine to an electro-muscular incapacitating device (TASER International's ADVANCED TASER X26 electronic control device) resulted in acidosis and increases in blood electrolytes. In the current study, experiments were performed to investigate effects of a more typical scenario of repeated exposures of the device on muscle contraction and changes in blood factors. Ten swine were exposed for 5s, followed by a 5-s period of no exposure, three times. Selected blood factors were monitored for 3h following exposure. Transient increases in blood glucose, lactate, sodium, potassium, calcium, and pCO(2) were consistent with previous reports in the literature dealing with studies of muscle stimulation or exercise. Blood pH was decreased immediately following exposure, but subsequently returned toward a normal level. Oxygen saturation (measured by pulse oximetry) was not changed significantly. In conclusion, three repeated TASER device exposures had only transient effects on blood factors, which all returned to pre-exposure levels, with the exception of hematocrit (which remained elevated after 3h). Since the increase in this factor was less than that which may occur after short periods of exercise, it is unlikely that this would be an indicator of any serious harm.     

Survival of anesthetized Sus scrofa after cycling (7-second on/3-second off) exposures to an electronic control device for 3 minutes

Electronic control devices (ECDs) may eventually be deployed by the military in a manner resulting in longer exposures than those encountered during law-enforcement operations. In a previous study, 18 repeated cycling (5-second on/5-second off) exposures (within a 3-minute period) of anesthetized swine to an ECD (TASER International's Advanced TASER X26 device) resulted in leg muscle contraction, acidosis, and increases in blood electrolytes. In the current study, experiments were performed to examine effects of exposures to a different cycling rate (7-second on/3-second off), from a modified X26 ECD, on 10 swine (Sus scrofa), maintained on propofol anesthesia. In contrast with the previous study, a large number of animals (6/10) died immediately after the exposures. There were no major differences in pre-exposure blood factors from survivors versus nonsurvivors, with the exception of hematocrit and 2 isoenzymes of lactate dehydrogenase. It is doubtful that these factors would be useful in predicting survival after ECD exposure. Blood pH was significantly decreased after exposure, but (in animals that survived) subsequently returned to baseline levels. On the basis of the overall survival rate, further development of useful ECDs (for long-term incapacitation during military operations) may require consideration of longer pauses between repeated exposures over a 3-minute period.     

40‐Hz Square‐Wave Stimulation Requires Less Energy to Produce Muscle Contraction: Compared with the TASER® X26 Conducted Energy Weapon

Conducted energy weapons (CEWs) (including the Advanced TASER^® X26 model produced by TASER International, Inc.) incapacitate individuals by causing muscle contractions. In this study using anesthetized swine, the potential incapacitating effect of primarily monophasic, 19‐Hz voltage imposed by the commercial CEW was compared with the effect of voltages imposed by a laboratory device that created 40‐Hz square waves. Forces of muscle contraction were measured with the use of strain gauges. Stimulation with 40‐Hz square waves required less pulse energy than stimulation with the commercial CEW to produce similar muscle contraction. The square‐pulse stimulation, at the higher repetition rate, caused a more complete tetanus at a lower energy. Use of such a simple shape of waveform may be used to make future nonlethal weapon devices more efficient.     

Muscle contraction during electro-muscular incapacitation: A comparison between square-wave pulses and the TASER(®) X26 Electronic control device

Abstract: Electronic control devices (including the Advanced TASER^® X26 model produced by TASER International) incapacitate individuals by causing muscle contractions. To provide information relevant to development of future potential devices, effects of monophasic square waves with different parameters were compared with those of the X26 electronic control device, using two animal models (frogs and swine). Pulse power, electrical pulse charge, pulse duration, and pulse repetition frequency affected muscle contraction. There was no difference in the charge required, between the square waveform and the X26 waveform, to cause approximately the same muscle‐contraction response (in terms of the strength‐duration curve). Thus, on the basis of these initial studies, the detailed shape of a waveform may not be important in terms of generating electro‐muscular incapacitation. More detailed studies, however, may be required to thoroughly test all potential waveforms to be considered for future use in ECDs.     

The Effects of Continuous Application of the TASER X26 Waveform on Sus scrofa,

This study investigated and evaluated the safety margins of the continuous long duration (up to 30 min) effect of the TASER X26 waveform, using a Sus scrofa model. Long duration continuous stimulus has not been evaluated on humans or human surrogates prior to this study. Swine were used as models due to similarities with humans in their skin and cardiovascular systems. Very long duration was used to determine both exposure dose and possible adverse physiological effects of dose. The trial began with an application of 10 min, and subsequent animals received increasing exposure time up to a survived maximum duration of 30 min. At the onset of this work, it was hypothesized that there would be a time limit after which most animals would not survive consistent with increased dose response. However, this hypothesis was not supported by the experimental results. All animals (10 of 10) survived up to 3 min. Seven of the 10 animals survived up to a 10‐min exposure and 3 of 5 animals with a 30‐min target exposure survived the full exposure. Surviving animals were recovered and observed for 24 h, with no postrecovery deaths. This suggests that swine (based on physiology) will not experience a fatal event when exposed to the TASER X26 for a continuous 3 min. Conclusions regarding longer duration (10–30 min) are not as certain due to the small sample sizes at these time intervals.     

Repetitive TASER X26 Discharge Resulted in Adverse Physiologic Events with a Dose–Response Relationship Related to the Duration of Discharge in Anesthetized Swine Model

The objectives of our study were to investigate the dose–response relationship of the TASER X26 discharge duration in an anesthetized swine model. Fourteen swines were anesthetized and then exposed to TASER X26 discharge for 5 sec (n = 5) or for 10 sec (n = 6). The sham control group (n = 3) was anesthetized and studied using the same protocol except TASER X26 discharges during the experiments. Hemodynamic parameters were obtained. Blood pressure and total peripheral resistance decreased significantly after TASER discharge and returned to baseline value at 15 min after 5 sec of TASER discharge but did not return to baseline values during the 30‐min observation period after 10 sec of TASER discharge. Repetitive TASER X26 discharge resulted in adverse physiologic events with a dose–response relationship related to the duration of TASER X26 discharge in an anesthetized swine model.     

An Animal Model to Investigate Effectiveness and Safety of Conducted Energy Weapons (Including TASER® Devices)*

Abstract: Conducted energy weapons (CEWs) are used by law‐enforcement personnel to incapacitate individuals quickly and effectively, without causing lethality. CEWs have been deployed for relatively long or repeated exposures during law‐enforcement operations. The purpose of this technical note is to describe, in detail, some aspects of an anesthetized swine model used in our laboratory and to answer specific questions related to the model. In particular, tiletamine/zolazepam‐induced, propofol‐maintained anesthesia appears to be a useful technique for studying effects of CEW applications on muscle contraction and blood factors such as muscle enzymes. Because effects of CEWs on breathing have not been fully elucidated, a spontaneously breathing model is preferable to one in which mechanical ventilation is supplied. Placement of the swine in a supine position may facilitate measurement of muscle contractions, without compromising other physiological parameters.     

Increased hematocrit after applications of conducted energy weapons (including TASER(®) devices) to Sus scrofa

Conducted energy weapons (CEWs) are used by law enforcement personnel to incapacitate individuals quickly and effectively, without intending to cause lethality. CEWs have been deployed for relatively long or repeated exposures in some cases. In laboratory animal models, central venous hematocrit has increased significantly after CEW exposure. Even limited applications (e.g., three 5-sec applications) resulted in statistically significant increases in hematocrit. Preexposure hematocrit was significantly higher in nonsurvivors versus survivors after more extreme CEW applications. The purpose of this technical note is to address specific questions that may be generated when examining these results. Comparisons among results of CEW applications, other electrical muscle stimulation, and exercise/voluntary muscle contraction are included. The anesthetized swine appears to be an acceptable animal model for studying changes in hematocrit and associated red blood cell changes. Potential detrimental effects of increased hematocrit, and considerations during law enforcement use, are discussed.     

Examining the effects of the TASER on cognitive functioning: findings from a pilot study with police recruits

Objectives

Despite its widespread adoption by more than two-thirds of police departments in the US, there has not been a single study examining the effects of the TASER on cognitive functioning. This inquiry is important for two reasons. First, research has consistently documented cognitive deficits following exposure to electricity (the TASER is an electrical device). Second, questions have emerged regarding whether TASER exposure impairs suspects’ ability to understand and waive their Miranda rights.

Methods

To explore this issue, the authors carried out a pilot study with 21 police recruits who received a TASER exposure as part of their training at the San Bernardino County (CA) Training Center. Each recruit was given a battery of cognitive tests 3–4 h before TASER exposure, within 5 min after exposure, and again 24 h after exposure.

Results

Recruits experienced statistically significant reductions in several measures of cognitive functioning following TASER exposure. However, all recruits had returned to their baseline levels of functioning within 24 h. Learning effects were documented in several of the cognitive tests.

Conclusions

The questions driving this study involve serious issues including constitutionally protected rights of the accused, use of force by police, and previously unexamined effects of the TASER on the human body. The pilot study represents a critical first step in exploring the effects of the TASER on cognitive functioning. Moreover, the results provided the authors with important information that will guide their larger study, a randomized controlled trial where healthy human volunteers will be randomly assigned to four groups, two of which receive a TASER exposure.     

Pulse Variations of a Conducted Energy Weapon (Similar to the TASER® X26 Device): Effects on Muscle Contraction and Threshold for Ventricular Fibrillation*

Abstract: Conducted energy weapons (such as the Advanced TASER X26 model produced by TASER International), incapacitate individuals by causing muscle contractions. To provide information relevant to development of future potential devices, a “Modifiable Electronic Stimulator” was used to evaluate the effects of changing various parameters of the stimulating pulse. Muscle contraction was affected by pulse power, net/gross charge, pulse duration, and pulse repetition frequency. The contraction force increased linearly as each of these factors was increased. Elimination of a precursor pulse from X26‐like pulses did not have a significant effect on the normalized force measured. Muscle‐contraction force increased as the spacing increased from 5 to 20 cm, with no further change in force above 20 cm of spacing. Therefore, it is suggested that any future developments of new conducted energy weapons should include placement of electrodes a minimum of 20 cm apart so that efficiency of the system is not degraded. In the current study, the 50% probability of fibrillation level of X26‐like pulses ranged from 4 to 5 times higher than the X26 itself. Relatively large variations about the X26 operating level were found not to result in fibrillation or asystole. Therefore, it should be possible to design and build an X26‐type device that operates efficiently at levels higher than the X26.     

Examining fatal and nonfatal incidents involving the TASER

Research Summary According to TASER International, nearly 10,000 police departments in the United States have deployed the TASER as a less lethal force alternative in some capacity. Despite the TASER's increasing popularity, serious questions have been raised about the device's physiological side effects; in particular, Amnesty International has reported that more than 300 people have died after being subjected to the TASER. Although a growing body of research has examined the physiological effects of the TASER on animals and healthy human volunteers in laboratory settings, there has been virtually no empirical analysis of “real‐world” fatal and nonfatal TASER cases simultaneously. This article examines all media reports of TASER incidents from 2002 to 2006 through a comprehensive review of LexisNexis and New York Times archives. We compare TASER incidents in which a fatality occurred to TASER incidents in which a fatality did not occur and then employ multivariate analyses to identify the incident and suspect characteristics that are predictive of articles describing TASER‐proximate deaths. Policy Implications Several suspect factors were significantly associated with the reporting of a fatal TASER incident, including drug use (but not alcohol), mental illness, and continued resistance. Multiple deployments of the TASER against a suspect was also associated with the likelihood of the article describing a fatality—especially if the suspect was emotionally disturbed—which raises the possibility that the risk of multiple shocks might not be uniform for all suspects. More research is needed to explore the relationship between mental illness, drug use (illicit or therapeutic), continued resistance, and increased risk of death. In the meantime, police departments should develop specific policies and training governing the use of multiple TASER shocks against individuals who could be in these vulnerable physiological and psychological states.     

Can the direct cardiac effects of the electric pulses generated by the TASER X26 cause immediate or delayed sudden cardiac arrest in normal adults?

There is only a small amount of experimental data about whether the TASER X26, a nonlethal weapon that delivers a series of brief electrical pulses to cause involuntary muscular contraction to temporarily incapacitate an individual, can initiate ventricular fibrillation to cause sudden cardiac arrest either immediately or sometime after its use. Therefore, this paper uses the fundamental law of electrostimulation and experimental data from the literature to estimate the likelihood of such events. Because of the short duration of the TASER pulses, the large duration of the cardiac cell membrane time constant, the small fraction of current from electrodes on the body surface that passes through the heart, and the resultant high pacing threshold from the body surface, the fundamental law of electrostimulation predicts that the TASER pulses will not stimulate an ectopic beat in the large majority of normal adults. Since the immediate initiation of ventricular fibrillation in a normal heart requires a very premature stimulated ectopic beat and the threshold for such premature beats is higher than less premature beats, it is unlikely that TASER pulses can immediately initiate ventricular fibrillation in such individuals through the direct effect of the electric field generated through the heart by the TASER. In the absence of preexisting heart disease, the delayed development of ventricular fibrillation requires the electrical stimuli to cause electroporation or myocardial necrosis. However, the electrical thresholds for electroporation and necrosis are many times higher than that required to stimulate an ectopic beat. Therefore, it is highly unlikely that the TASER X26 can cause ventricular fibrillation minutes to hours after its use through direct cardiac effects of the electric field generated by the TASER.     

Police use of TASER devices in mental health emergencies: A review

The proliferation of TASER devices among police forces internationally has been accompanied by concerns about injuries and health effects, and about the use of TASER devices on vulnerable populations such as people with mental illness. TASER devices have generated a flood of research studies, although there remain unanswered questions about some of the key issues. This paper outlines the introduction of TASER devices to policing and their subsequent widespread adoption. The paper considers the role of police in mental health emergencies with a particular focus on use of TASER devices. Some factors contribute to the special vulnerability of people with mental illness to the effects of TASER devices. The paper also reviews research into use of TASER devices and raises issues about conflict of interest in research into TASER devices. We conclude that TASER devices look set to play a significant role in policing in the future. We make suggestions for a future research programme, and suggest guidelines for publication of papers in which there may be a conflict of interest.     

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.     

Lowered cold tolerance in cold-acclimated and non-acclimated guinea pigs treated with diazepam

The effects of the clinically most commonly used minor tranquilizer, diazepam, on the survival time and on the mechanism of death in non-acclimated and cold-acclimated guinea pigs in severe cold exposure (-20 degrees C) were studied. Cold acclimation for 2 months increased the average survival time from 4 h to 10 h. The lowest rectal temperature at death (14.6 degrees C) was seen in the cold-acclimated animals. Diazepam at a dose of 5 or 15 mg/kg i.p. 30 min before the beginning of the exposure reduced dose-dependently the cold endurance of both cold-acclimated and non-acclimated guinea pigs. The serum glucose and free fatty acid concentrations were low in the animals with the long survival time. Histological studies of liver, kidney, and adrenal glands showed no specific changes. Exposure seemed to increase the frequency of contraction bands and to decrease focally the intensity of beta-hydroxybutyrate dehydrogenase reaction in the myocardium, which indicates a mild hypoxic lesion of the muscle cells.     

肢体肌肉功能评定研究进展

肢体肌肉功能的评定一直是法医临床学领域的一大难题.近年来,法医临床学鉴定实践中需要进行肢体肌肉功能评定的案件呈增多趋势,肢体肌肉功能评定方法的研究也日益受到重视.本文介绍了肌肉功能的分类和肌肉收缩的类型,对徒手肌力评定、简单器械肌力测试、等速肌力测试、神经电生理检测等肢体肌肉功能的评定方法及其应用价值进行了综述,并提出...     

Technological Innovation and Police Officers' Understanding and Use of Force

Today, the TASER is a ubiquitous less‐than‐lethal force technology lauded for its ability to curb police officers' use of excessive and lethal force. Although less injurious than other weapons, concerns exist that the TASER can still be misused by police officers. This article uses ethnographic observations and unstructured interviews across three urban police departments to describe how the TASER affects officers' understanding and use of force in beneficial and unintended ways. I find that officers understand and use the TASER as a device that can enhance safety for themselves and suspects, including in cases where the TASER is used in lieu of lethal force that officers believe would have been justified. Despite these benefits, understanding of the TASER as a safety‐enhancing technology also influences the use of excessive force via TASER by young, inexperienced officers, ultimately contributing to the very problem TASERs were intended to ameliorate.     

Damage characteristics of fabrics created by TASER probes

TASER® weapons are conducted energy weapons (CEWs) that are frequently used by police departments around the world. CEWs can be deployed in two methods: drive stun application and probe deployment. This study aims to examine damages caused by TASER devices on fabrics and whether types of fabric material and TASER models could contribute to different damage features. Three types of white fabric were used, including 100% cotton, 100% polyester, and 65:35 polyester-cotton blend. Three models: TASER X26P, TASER X2, and TASER 7 were shot onto each type of fabric, with five repetitions each. Each damaged area on the fabric caused by a probe is a sample (n = 90) and was examined with a Keyence digital microscope. Images were captured by the Keyence microscope and measurements were recorded, including damage dimensions, fabric condition, evidence of burning, and extra findings. The presence of fused yarn ends was found to be statistically significant across the fabric types, and no damage features were found that may assist in the identification of TASER models. Other damage features including damage dimensions, discoloration, and fiber deformation were not found to be showing apparent differences according to statistical analysis. The conclusions made by this research should be used with caution due to the small sample size.     

美国马里兰州涉及电击枪死亡案例分析

目的 研究美国马里兰州涉及电子武器(电击枪)死亡案件的特点,探讨其法医学鉴定要点.方法 收集2004-2009年美国马里兰州法医局鉴定的涉及电击枪死亡案件13例,案件均经详细的现场调查,尸体进行系统解剖,并进行全面的毒(药)物检测及组织病理学检验.从一般情况、电击枪类型及接触方式、毒物检测结果、死亡方式、死亡原因等方面...     

Police use of TASERs in the restraint and transport of persons with a mental illness

The mentally ill are overrepresented in the statistics of individuals killed or injured by police and it is understandable that police would seek a weapon, such as a TASER, that is less lethal than a firearm. However, it appears that use of TASERs is not without risk, especially in certain groups, including the mentally ill. The risk of injury to vulnerable people with a mental illness from TASER weapons must be weighed against the risk that escalation to lethal force may cause if a person with an acute mental illness requires restraint. When police officers are carrying out their duties under mental health legislation it is recommended that TASERs be used only when an individual is imminently likely to sustain or to cause grievous bodily harm. This article recommends changes to the Western Australian Police TASER training programs and proposes mandatory medical assessments after the use of TASER restraint.