While a considerable body of research has investigated the physiological risks associated with the TASER device, much less research attention has been devoted to examining the nearly 400 police-citizen encounters in which a suspect has died after the device was used. As a result, there are numerous unanswered questions regarding officer, suspect, and incident-level characteristics of these arrest-related deaths (ARDs), as well as the extent to which patterns in these characteristics may have changed over time. The current study seeks to inform the discourse surrounding these death cases through a descriptive analysis of the near-universe of ARDs involving a TASER device deployment from 2001-2008 (n = 392). Using a unique data triangulation methodology that captures both media (n = 392) and medical examiner reports (n = 213), the authors characterize the geographic distribution of ARDs and find parallels between that distribution, state population, the number of officers per state, crime levels per state, and TASER device sales patterns. Also, an incident-level analysis shows that these ARDs were dynamic encounters between suspects who were frequently intoxicated and who actively and aggressively resisted police, and officers who were drawing deeply into their arsenal of force options in an attempt to control and arrest them. Cause of death was most commonly identified as drugs, heart problems, or Excited Delirium Syndrome. Last, longitudinal analysis showed 86 Police Quarterly 16(1) consistency in most incident, suspect and officer characteristics, though key aspects of suspect resistance, including level of aggression and persistence after TASER device exposure, changed notably over time. The article concludes with a discussion of implications for policy and practice with regard to these rare but fatal police-citizen encounters.
It has been long recognized that there are 2 methods for inducing VF (ventricular fibrillation) with electrical currents‥ These are: (1) delivering a high-charge shock into the cardiac T-wave, and (2) delivering lower level currents for 1-5 seconds. Present electrical safety standards are based on this understanding. We present new data showing a 3(rd) mechanism of inducing VF which involves the steps of delivering sufficient current to cause high-rate cardiac capture, causing cardiac output collapse, leading to ischemia, for sufficiently long duration, which then lowers the VFT (VF threshold) to the level of the current, which finally results in VF. This requires about 40% of the normal VF-induction current but requires a duration of minutes instead of seconds for the VF to be induced. Anesthetized and ventilated swine (n=6) had current delivered from a probe tip 10 mm from the epicardium sufficient to cause hypotensive capture but not directly induce VF within 5 s. After a median time of 90 s, VF was induced. This 3(rd) mechanism of VF induction should be studied further and considered for electrical safety standards and is relevant to long-duration TASER Electronic Control Device applications.
Large aperture Plasma Electrode Pockels Cells (PEPCs) are an enabling technology in the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory. The Pockels cells allow the NIF laser to take advantage of multipass main amplifier architecture, thus reducing costs and physical size of the facility. Each Pockels cell comprises four 40-cm x 40-cm apertures arranged in a 4x1 array. The combination of the Pockels cell and a thin-film polarizer, also configured in a 4x1 array, forms an optical switch that is key to achieving the required multi-pass operation.The operation of the PEPC is a follows: Before the arrival of the laser pulse, optically transparent, low-density helium plasmas are initiated to serve as electrodes for the KDP crystals mounted in the Pockels cell. During beam propagation through the main laser cavity a longitudinal electric field is impressed on the electro-optic crystals. The polarization of the propagating beams is rotated by 90° on each of two passes, thereby allowing the beam to be trapped in the main laser amplifier cavity for a total of four passes before being switched out into the cavity spatial filter.The physics aspects of the PEPC are well documented. Consequently, this paper will emphasize the PEPC subsystem in the context of its role and relevance within the broader NIF laser system, provide a view of the complexity of the subsystem and give an overview of PEPC's interactions with other elements of NIF, including interfaces to the Beamline Infrastructure, the NIF Timing Subsystem, and the Integrated Computer Control System (ICCS); along with dependence on the Optics Production, Transport and Handling (T&H), and Assembly, Integration and Refurbishment (AIR) and Operations organizations. Further, we will discuss implementation details related to the functional blocks and individual components that comprise PEPC, with particular emphasis on the unique constraints placed on the elements and the attendant engineering solutions. Finally, we describe performance, fabrication and assembly requirements unique to PEPC and the various considerations necessary for successfully commissioning and operation of each PEPC unit. These considerations include, but are not limited to, materials choices, materials preparation and processing (especially cleanliness), inspection, pre-and post-assembly testing.
The TASER(R) CEW (Conducted Electrical Weapon) is rapidly replacing the club in the English-speaking world for assisting in the arrest of resistant subjects and is now used by the majority of law enforcement agencies in the USA, Canada, and the UK. Animal safety studies of the CEW have focused on the risk of VF. We sought to determine the difference in cardiac capture and VF risk between the approximately 102 +/- 8 microC of the ubiquitous X26 and a me-tered 72 microC charge from an experimental device. It is well established from the bidomain theory and experimental data that a pacing electrode will capture the heart with significantly lower charge when the electrode touching the cardiac tissue is a cathode However, experimental data show that there is no difference in the ability of the anode vs the cathode to induce VF. We sought to evaluate the effect of polarity changes on cardiac capture and the induction of VF. Small swine ( approximately 20.0 kg) were anesthetized and ventilated. The apex of the heart was located via echocar-diography and a CEW probe was fully inserted towards the apex. Echocardiography was used to monitor cardiac contractions to determine cardiac capture. Both the X26 and the 72 microC pulses were delivered at both polarities to test for cardiac capture. Higher charge pulses (375 microC) were then delivered with both polarities to test for VF risk. The 72 microC experimental unit was unable to cause cardiac capture even in small swine with fully inserted probes directly over the apex of the heart. We found no polarity effect in the risk of VF in small swine with larger charge ( approximately 5x) pulses.
The Plasma Electrode Pockels Cell (PEPC) subsystem is a key component of the National Ignition Facility, enabling the laser to employ an efficient four-pass main amplifier architecture. PEPC relies on a pulsed power technology to initiate and maintain plasma within the cells and to provide the necessary high voltage bias to the cells' nonlinear crystals. Ultimately, nearly 300 high-voltage, high-current pulse generators will be deployed in the NIF in support of PEPC.Production of solid-state plasma pulse generators and thyratron-switched pulse generators is now complete, with the majority of the hardware deployed in the facility. An entire cluster (one-fourth of a complete NIF) has been commissioned and is operating on a routine basis, supporting laser shot operations. Another cluster has been deployed, awaiting final commissioning. Activation and commissioning of new hardware continues to progress in parallel, driving toward a goal of completing the PEPC subsystem in late 2007.
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