Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference
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Annu Int Conf IEEE Eng Med Biol Soc · Jul 2017
New conducted electrical weapons: Finite element modeling of safety margins.
Introduction-We have previously published on the ventricular fibrillation (VF) risk with TASER® X26 conducted electrical weapon (CEW). Our risk model accounted for realistic body mass index distributions, modeled the effects of partial or oblique dart penetration, and used epidemiological CEW statistics. As new CEWs have become available to law enforcement, their cardiac safety profile was not quantified. ⋯ We also found that the XRF and X2 CEWs had increased cardiac safety margins with respect to those previously reported for the X26 CEWs when all three CEW models were operated with 9 mm CEW darts. Lastly, the cardiac risk of these new CEWs (<; 0.76 ppm) was found to be much lower than reported levels of CEW non-cardiac fatal injuries (e.g. falls and burns, > 7.2 ppm). Conclusions-While not risk-free, the new TASER XRF and X2 CEWs offer increased cardiac safety margins and extremely low cardiac risk profiles.
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Annu Int Conf IEEE Eng Med Biol Soc · Jul 2017
New conducted electrical weapons: Electrical safety relative to relevant standards.
We have previously published about TASER® conducted electrical weapons (CEW) compliance with international standards. CEWs deliver electrical pulses that can inhibit a person's neuromuscular control or temporarily incapacitate. An eXperimental Rotating-Field (XRF) waveform CEW and the X2 CEW are new 2-shot electrical weapon models designed to target a precise amount of delivered charge per pulse. They both can deploy 1 or 2 dart pairs, delivered by 2 separate cartridges. Additionally, the XRF controls delivery of incapacitating pulses over 4 field vectors, in a rotating sequence. As in our previous study, we were motivated by the need to understand the cardiac safety profile of these new CEWs. The goal of this paper is to analyze the nominal electrical outputs of TASER XRF and X2 CEWs in reference to provisions of all relevant international standards that specify safety requirements for electrical medical devices and electrical fences. Although these standards do not specifically mention CEWs, they are the closest electrical safety standards and hence give very relevant guidance. ⋯ Our study confirmed that the nominal electrical outputs of TASER XRF and X2 CEWs lie within safety bounds specified by relevant standards.
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High rates of false monitoring alarms in intensive care can desensitize staff and therefore pose a significant risk to patient safety. Like other critical arrhythmia alarms, asystole alarms require immediate attention by the care providers as a true asystole event can be acutely life threatening. Here, it is illustrated that most false asystole alarms can be attributed to poor signal quality, and we propose and evaluate an algorithm to identify data windows of poor signal quality and thereby help suppress false asystole alarms. ⋯ The algorithm achieved an alarm specificity of 81.0% and sensitivity of 95.4%, missing only one out of 22 true asystole alarms. On a separate neonatal data set, the algorithm was able to reject 89.7% (890 out of 992) of false asystole alarms while keeping all 22 true events. The results show that the false asystole alarm rate can be significantly reduced through basic signal quality evaluation.
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Annu Int Conf IEEE Eng Med Biol Soc · Jul 2017
Investigating the effect of cardiac oscillations and deadspace gas mixing during apnea using computer simulation.
Gaseous mixing in the anatomical deadspace with stimulation of respiratory ventilation through cardiogenic oscillations is an important physiological mechanism at the onset of apnea, which has been credited with various beneficial effects, e.g. reduction of hypercapnia during the use of low flow ventilation techniques. In this paper, a novel method is proposed to investigate the effect of these mechanisms in silico. ⋯ Computational simulations confirm that the model outputs accurately reproduce the available experimental data. This new model can be used to investigate the physiological mechanisms underlying clearance of carbon dioxide during apnea, and hence to develop more effective ventilation strategies for apneic patients.
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Annu Int Conf IEEE Eng Med Biol Soc · Jul 2017
A study of color illumination effect on the SNR of rPPG signals.
Remote photoplethysmography (rPPG) can be used to measure cardiac activity by detecting the subtle color variation of the human skin tissue using an RGB camera. Recent studies have presented the feasibility and proposed multiple methods to improve the motion robustness for the subject movements. However, enhancing the signal-to-noise ratio (SNR) of the rPPG signal is still an important issue for the contactless measurement. ⋯ The results point out that different colors of light sources provide different SNR in each RGB channel. By providing the dedicated light sources (λ= 490-620) nm, the SNR of rPPG signals captured from the green color channel can be enhanced. Among the tested light sources, light green provides the most significant improvement from -11.09 to -6.6 dB compared with the fluorescent light.