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.     

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.     

Exposures to Conducted Electrical Weapons (Including TASER® Devices): How Many and for How Long are Acceptable?

TASER^® conducted electrical weapons (CEWs) are an important law-enforcement tool. The purposes of this study are a) to review recent literature regarding potential pathophysiological responses to applications of CEWs, and other related issues and b) to evaluate whether enough data exist to determine the acceptability of longer-duration (or repeated) exposures. This is a narrative review, using a multidisciplinary approach of analyzing reports from physiological, legal-medical, and police-strategy literature sources. In general, short-duration exposures to CEWs result in limited effects. Longer-duration or repeated exposures may be utilized with caution, although there are currently not enough data to determine the acceptability of all types of exposures. Data examined in the literature have inherent limitations. Appropriateness of specific types of CEW usage may be determined by individual police agencies, applying risk/benefit analyses unique to each organization. While more research is recommended, initial concepts of potential future long-duration or repeated CEW applications are presented.     

Traumatic Death in Ankylosing Spondylitis

Abstract: Ankylosing spondylitis (AS) is a chronic rheumatic disease that causes spinal rigidity with an increased risk of spinal fractures. We present a case report where a middle‐aged man, in apparent good health, died following a fall from his bike. Postmortem computed tomography (CT) showed several fractures in the cervical and thoracic spine, with displacement into the spinal canal as well as spinal changes consistent with AS. The cause of death was determined to be upper spinal cord injury caused by cervical spinal fractures that were facilitated by spinal rigidity from AS. Further investigation into the medical records revealed that the decedent had previously been treated for AS. This case report illustrates the importance of obtaining a detailed medical history when investigating deaths, including nonfatal conditions, such as AS. Furthermore, it shows the value of CT in the evaluation of the mechanism and manner of death.     

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.     

Can Birth Trauma Be Confused for Abuse?

Abstract: An unexpected infant death is usually investigated with a complete autopsy. If evidence of prior trauma is found at autopsy in these cases, suspicion is raised for nonaccidental trauma. In a young infant, the residua of trauma received during birth has the potential to be incorrectly interpreted as nonaccidental trauma. We report a the findings of a 4 1/2‐month‐old‐infant that died unexpectedly with a healing linear skull fracture and a circular lesion over the calvarium found at autopsy. Though this lesion was concerning, the remainder of the autopsy and the histological findings did not support a diagnosis of recent trauma. Review of the literature describing birth injuries made the diagnosis of healing, residual birth trauma more convincing in this case.     

Comparative Analysis of the Effects of Heat on the PCR‐Amplification of Various Sized DNA Fragments Extracted from Sus Scrofa Molars*

Abstract: This study examined the effects of heat on the amplification of DNA from the dental pulp of Sus scrofa molars and investigated the protection afforded to the pulp tissue by the dental enamel, alveolar process, and soft tissue of the head. Segments of defleshed maxilla and mandible encasing the first molar (n = 60) were subject to a range of temperatures for 15 min. Dental pulps were retrieved. Amplifications using three‐primer and four‐primer multiplexes showed no degradation of the largest fragment following exposure to 450°C. Amplifications in the three‐primer multiplex (283 bp) were successful following exposure to 525°C in maxillary samples only. This study revealed the enamel density of maxillary molars to be greater than mandibular molars in Sus scrofa. Following incineration of intact heads for 15 min (n = 10) and 1 h (n = 4) at an average temperature of 625°C, amplifications of the largest fragment (450 bp) were successful from both maxillary and mandibular teeth.     

Forensic Imaging‐Guided Recovery of Nuclear DNA from the Spinal Cord*,†

Abstract: Our objective is to document the recovery of DNA from the spinal cord or surrounding dura mater in 11 cases of severely burned human remains. Radiographs established that portions of charred tissue contained spine segments. Multidetector computed tomography (MDCT) revealed that each spine specimen contained an intact spinal cord remnant. A full DNA profile was obtained from seven specimens using spinal cord dura mater in six specimens and spinal cord medulla in one specimen. A partial profile was obtained from four specimens (spinal cord dura mater, 2; spinal cord medulla, 2). Bone and muscle surrounding the spinal cord appear to insulate nucleic acid containing tissue from critical thermal degradation. The spinal cord, which is easily identified by MDCT examination of remains and easily recovered at the postmortem examination, can be a source of DNA with extraction yields comparable with other tissue sources. Specimens of dura mater are preferable as processing time is faster than bone.     

Functioning and Effectiveness of Electronic Control Devices Such as the TASER® M‐ and X‐Series: A Review of the Current Literature

Abstract: Conducted electrical weapons (CEWs) such as the TASER^® M‐ and X‐series deliver short high‐voltage, low‐current energy pulses to temporarily paralyze a person by causing electrical interruption of the body’s normal energy pulses. Despite many scientific publications, which classify the health risks of an appropriate use of the TASER device as minor, there still is a continuous uncertainty about possible side effects with human application. Based on a literature search of the National Library of Medicine’s MEDLINE database’s PubMed system of current publications, the following article describes the mechanisms by which the device operates and discusses possible pathophysiological consequences. The majority of current human literature has not found evidence of clinical relevant pathophysiological effects during and after an exposure of professionally applied CEWs. However, to be able to exclude possible health risks, a medical checkup of people who have been exposed to CEWs is essential.