Abstract 63: Hands-On Defibrillation: An Analysis of Current Flow Through Rescuers In Contact With Patients During Biphasic External Defibrillation

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Michael S Lloyd ◽  
Eric L Krivitsky ◽  
Paul F Walter ◽  
Jonathan J Langberg
Keyword(s):  
Leakage Current ◽  
Current Flow ◽  
Chest Compressions ◽  
Case Scenario ◽  
Storage Oscilloscope ◽  
Worst Case ◽  
Shock Delivery ◽  
Digital Storage ◽  
Posterior Shoulder ◽  
Flow Through

Background: During cardiopulmonary resuscitation, the need for rescuers to stand clear before a shock is delivered invariably interrupts chest compressions. Brief interruptions like these reduce the efficacy of defibrillation in animal models. Current flow through a rescuer in contact with a patient being shocked with modern biphasic waveforms and adhesive patch electrodes has not been investigated. We hypothesized that leakage current is low through a rescuer performing chest compressions at the time of shock delivery. Methods: During 18 elective cardioversions using truncated exponential biphasic waveforms (median energy 200 joules, range 100 –360 joules), an investigator serving as the rescuer placed a gloved hand on the patient’s anterior chest immediately adjacent to the defibrillating patch with approximately 20lbs of pressure to simulate chest compressions. Skin electrodes were used to connect the rescuer’s thigh to the patient’s posterior shoulder, simulating a worst-case return current pathway. During shock delivery, voltage and current through the rescuer (hand to thigh) were recorded using a digital storage oscilloscope during the shock delivery. Results: In no cases were shocks perceptible to the rescuer. Mean patient transthoracic impedance was 57 +/− 14 ohms (range 36 –79 ohms). Potential differences in volts (V) between the rescuer’s wrist and thigh ranged from 1.7 to 14 V (mean 6.7 +/− 2.7 V). Calculated impedances through rescuers ranged from 8,190 to 100,400 ohms (mean 30,100 +/− 20,400 ohms). The average leakage current flowing through the rescuer’s body for each phase of the shock waveform was 273 +/−191 microamperes (range 1 to 910 microamperes). All measured values in our series were well below 2,500 microamperes, an accepted safety standard for earth-leakage current in medical devices. Conclusions: Even in a simulated worst-case scenario, a rescuer performing chest compressions during biphasic external defibrillation is exposed to low levels of leakage current. Our findings demonstrate the safety and feasibility of uninterrupted chest compressions during shock delivery, which may enhance the efficacy of defibrillation and cardiocerebral perfusion.

Abstract 312: "Stand Clear" Belongs to the Past: A Solution for Safe Hands-on Defibrillation

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Jakob E Thomsen ◽  
Graham W Petley ◽  
Bo Løfgren ◽  
Charles D Deakin
Keyword(s):  
Leakage Current ◽  
Chest Compression ◽  
Chest Compressions ◽  
Case Scenario ◽  
Worst Case ◽  
The Past ◽  
Worst Case Scenario ◽  
Hands On ◽  
Class 1 ◽  
Additional Point

Introduction: Interruptions to chest compressions during defibrillation reduce the chances of subsequent ROSC and successful defibrillation. Safe hands-on defibrillation (HOD) will allow uninterrupted chest compression during defibrillation and may improve resuscitation success. We tested the safety of rescuer contact with the patient (at the waist) whilst additionally wearing electrical insulating gloves during clinical defibrillation; a worst case scenario. Materials and Method: Leakage current flowing from the patient to the ‘rescuer’ during defibrillation of patients undergoing elective defibrillation was measured. The ‘rescuer’ remained in contact with the patient during defibrillation, wearing Class 1 electrical insulating gloves while simulating an inadvertent contact with the patient, through an additional wired contact between rescuer’s waist and patient. The results were compared with an international safety threshold of 1 mA. Results: Data from 67 shocks of variable biphasic energy from a total of 50 patients was recorded. The median leakage current from all defibrillations was 30 μA, (range: 7 - 164). Of the 34 of the shocks delivered at 360J the median leakage current was 62 μA (range: 13 - 164), all below the safety threshold of 1 mA. Conclusion: This study demonstrates that leakage current through the rescuer is within a safe threshold to allow hands-on defibrillation when using electrically insulated gloves and in the presence of an additional point of contact with the patient

Pediatric Defibrillation: Current Flow Is Improved by Using "Adult" Electrode Paddles

PEDIATRICS ◽  
1994 ◽  
Vol 94 (1) ◽  
pp. 90-93
Author(s):  
Dianne L. Atkins ◽  
Richard E. Kerber
Keyword(s):  
Surface Area ◽  
Current Flow ◽  
Experimental Studies ◽  
University Of Iowa ◽  
Shock Delivery ◽  
Peak Current ◽  
Transthoracic Impedance ◽  
Flow Through ◽  
Few Data ◽  
The University

Objective. Current flow, the major determinant of defibrillation success, depends on delivered energy and transthoracic impedance. Previous experimental data suggest that transthoracic impedance is higher using "pediatric" electrode paddles compared to the larger "adult" electrode paddles. There are few data from actual shocks to support the experimental studies. The purpose of this study was to measure transthoracic impedance during actual shock delivery and to determine the optimal electrode paddle size for pediatric defibrillation and cardioversion. Methods. We prospectively evaluated all shocks of ≤ 20 joules given to pediatric patients at the University of Iowa from 1988 to 1992. Data collected included energy selected by the operator, energy delivered by the defibrillator, peak current flow and transthoracic impedance. Data were analyzed by unpaired t test and linear regression. Results. Fifty-five shocks were delivered to 20 patients, age newborn to 8 years. Thirty-seven shocks were given with "pediatric" electrode paddles (surface area 21 cm2) and 18 with "adult" electrode paddles (surface area 83 cm2). Selected energy correlated well with delivered energy (r = .98, P < .0001). Delivered energy using "pediatric" electrodes did not differ from that delivered with "adult" electrodes (8.0±0.9 joules vs 10.5 ± 1.2 joules P > .1). However transthoracic impedance was significantly higher with "pediatric" electrodes (78.1±4.4 ohms vs 54.6 ± 2.7 ohms P < .0008), resulting in lower peak current flow through "pediatric" electrode paddles (6.2±0.5 amps vs 8.7 ± 0.5 amps P < .002). There was no correlation between joules/kg and peak current flow (r = .26, P > .05). Conclusion. Use of "pediatric" electrode paddies results in higher transthoracic impedance and thus lower peak current flow. In pediatric defibrillation, larger "adult" electrode paddies should be used as soon as chest size permits (approximateiy 10 kg). Lower transthoracic impedance results in higher current flow that facilitates cardioversion and defibrillation.

Reducing Probabilistic Weather Forecasts to the Worst Case Scenario: Anchoring Effects

2008 ◽  
Author(s):  
Sonia Savelli ◽  
Susan Joslyn ◽  
Limor Nadav-Greenberg ◽  
Queena Chen
Keyword(s):  
Case Scenario ◽  
Worst Case ◽  
Weather Forecasts ◽  
Worst Case Scenario ◽  
Anchoring Effects

THE EFFECT OF OXYGEN ADSORPTION ON THE CONDUCTIVITY OF PBTE FILMS.

2020 ◽  
Vol 6 (8(77)) ◽  
pp. 21-23
Author(s):  
S.N. Sarmasov ◽  
R.Sh. Rahimov ◽  
T.Sh. Abdullayev
Keyword(s):  
Spectral Region ◽  
Current Flow ◽  
Oxygen Adsorption ◽  
Tunneling Mechanism ◽  
Pn Junction ◽  
Flow Through ◽  
Pn Junctions ◽  
Effect Of Oxygen

The effect of oxygen adsorption on the conductivity of PbTe films is studied. Pn junctions based on PbTe films are photosensitive in the IR spectral region with a maximum photosensitivity of 𝜆𝑚𝑎𝑥 microns. The tunneling mechanism of current flow through the pn junction is shown.

EXPEDITION TO MALI, 2020

2020 ◽  
pp. 12-28
Author(s):  
D. V. Vaniukova ◽  
◽  
P. A. Kutsenkov ◽  
Keyword(s):  
Mass Murder ◽  
The State ◽  
Case Scenario ◽  
Worst Case ◽  
Traditional Art ◽  
Peter The Great ◽  
State Museum ◽  
Bobo Dioulasso ◽  
Oriental Studies ◽  
The Village

The research expedition of the Institute of Oriental studies of the Russian Academy of Sciences has been working in Mali since 2015. Since 2017, it has been attended by employees of the State Museum of the East. The task of the expedition is to study the transformation of traditional Dogon culture in the context of globalization, as well as to collect ethnographic information (life, customs, features of the traditional social and political structure); to collect oral historical legends; to study the history, existence, and transformation of artistic tradition in the villages of the Dogon Country in modern conditions; collecting items of Ethnography and art to add to the collection of the African collection of the. Peter the Great Museum (Kunstkamera, Saint Petersburg) and the State Museum of Oriental Arts (Moscow). The plan of the expedition in January 2020 included additional items, namely, the study of the functioning of the antique market in Mali (the “path” of things from villages to cities, which is important for attributing works of traditional art). The geography of our research was significantly expanded to the regions of Sikasso and Koulikoro in Mali, as well as to the city of Bobo-Dioulasso and its surroundings in Burkina Faso, which is related to the study of migrations to the Bandiagara Highlands. In addition, the plan of the expedition included organization of a photo exhibition in the Museum of the village of Endé and some educational projects. Unfortunately, after the mass murder in March 2019 in the village of Ogossogou-Pel, where more than one hundred and seventy people were killed, events in the Dogon Country began to develop in the worst-case scenario: The incessant provocations after that revived the old feud between the Pel (Fulbe) pastoralists and the Dogon farmers. So far, this hostility and mutual distrust has not yet developed into a full-scale ethnic conflict, but, unfortunately, such a development now seems quite likely.

Water Temperature Control Using PID Control System Based on LabVIEW

2016 ◽  
Vol 4 (2) ◽  
pp. 35-46
Author(s):  
Ari Ramadhani
Keyword(s):  
Water Temperature ◽  
Pid Control ◽  
Temperature Sensor ◽  
Pid Controller ◽  
Current Flow ◽  
Electrical Energy ◽  
Heating Process ◽  
Water Heater ◽  
Digital Thermometer ◽  
Flow Through

Abstract - Automatic system have grown widespread across all sector so do water heater. Traditionally, heating water is done by utilizing fire as heat source. As the growing of technology, the heating process could be done by manipulating electrical energy by convert it to heat. Electrical energy is flown to a metal rod that contact directly with the water which increase the water temperature. On some case, appropiate water temperature is needed. Altough, a thermometer is needed to read the actual temperature as a feedback value for the system and a system that can control the electricity current flow through the heater that the heat produced is linear to the current flow. With implementing microcontroller as a process node for generating PWM signal, this problem can be solved. Also, Labview is needed as an interface for monitoring and bursting an output which have been processed by Proportional, Integral, and Devivative (PID) controller to producing accurate and stable heat. Based on the results of testing, the system is able to provide a rapid response to any changes that occur, both changes in set-point and changes in water temperature (actual value). Another test is done by comparing the temperature value detected by the temperature sensor in this device with an external digital thermometer placed in the same place, and from some of the tests the temperature value detected by the temperature sensor in this device has a difference of ± 0.19 ℃ with a digital thermometer. Keyword : Water Heater, Thermometer, Microcontroller, LabView, PID.

Risk-Based Robust Bidding Strategies for EVs’ Aggregators in Day-ahead Markets with Uncertainty

2020 ◽  
Author(s):  
Ahmed Abdelmoaty ◽  
Wessam Mesbah ◽  
Mohammad A. M. Abdel-Aal ◽  
Ali T. Alawami
Keyword(s):  
Robust Optimization ◽  
Electricity Market ◽  
Real Life ◽  
Optimization Approach ◽  
Case Scenario ◽  
Worst Case ◽  
Bidding Strategies ◽  
Wind Generators ◽  
Proposed Model ◽  
Optimal Bidding

In the recent electricity market framework, the profit of the generation companies depends on the decision of the operator on the schedule of its units, the energy price, and the optimal bidding strategies. Due to the expanded integration of uncertain renewable generators which is highly intermittent such as wind plants, the coordination with other facilities to mitigate the risks of imbalances is mandatory. Accordingly, coordination of wind generators with the evolutionary Electric Vehicles (EVs) is expected to boost the performance of the grid. In this paper, we propose a robust optimization approach for the coordination between the wind-thermal generators and the EVs in a virtual<br>power plant (VPP) environment. The objective of maximizing the profit of the VPP Operator (VPPO) is studied. The optimal bidding strategy of the VPPO in the day-ahead market under uncertainties of wind power, energy<br>prices, imbalance prices, and demand is obtained for the worst case scenario. A case study is conducted to assess the e?effectiveness of the proposed model in terms of the VPPO's profit. A comparison between the proposed model and the scenario-based optimization was introduced. Our results confirmed that, although the conservative behavior of the worst-case robust optimization model, it helps the decision maker from the fluctuations of the uncertain parameters involved in the production and bidding processes. In addition, robust optimization is a more tractable problem and does not suffer from<br>the high computation burden associated with scenario-based stochastic programming. This makes it more practical for real-life scenarios.<br>

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