# Shared Flashcard Set

## Details

Electricity & Electrical Safety
Week 4
29
Physics
09/16/2015

Term
 Ohm's Law
Definition
 E=IR   Voltage= Amperage x Resistance
Term
 Voltage
Definition
 Amperage x Resistance   E=IR
Term
 Power
Definition
 Measured in watts   Voltage x Amperage   E x I
Term
 Electrical Work
Definition
 Watts x seconds    Measured in Joules
Term
 Direct Current   (DC)
Definition
 Electron flow is always in the same direction
Term
 Alternating Current    (AC)
Definition
 Electron flow reverses at regular intervals
Term
 Impedance   (Z)
Definition
 resistive force in an AC circuit
Term
 Z formulas
Definition
 Frequency x inductance    or    1 frequency x capacitance
Term
 Capacitance
Definition
 The greater the frequency the less the impedance
Term
 Inductance
Definition
 An opposing force can be induced in a separate wire or iron core
Term
 Circuit Breakers
Definition
 15-20 A   Do no protect against lethal shock
Term
 USA Power Supply
Definition
 120 V at 60 Hz
Term
 Tissue Damage
Definition
 Disruption of normal cellular electrical activity   Thermal Injury
Term
 Macroshock
Definition
 Large amount of current flow   in excess of 5 mA
Term
 Threshold of Perception
Definition
 1 mA
Term
 "Let- Go" Current
Definition
 10-20 mA
Term
 Pain
Definition
 50 mA
Term
 V-Fib
Definition
 100- 300 mA
Term
 Extensive Tissue Damage
Definition
 6000 mA
Term
 Current density
Definition
 current applied per unit area
Term
 OR Power
Definition
 Ungrounded   Accomplished with isolation transformer   Equipment casings will be grounded and allow discharge of leakage current
Term
 Line Isolation Monitors
Definition
 Monitor the integrity of power system   Measures circuit impedence to ground    Indicated in mA total possible current flow to ground
Term
 Line Isolation Monitor Alarms
Definition
 2-5 mA   Alarms when faulty piece of equipment allows more than 5 mA   Alarms sum of many small leakages from various equipment reach 5 mA   Cannot detect a faulty gorund wire
Term
 Ground Fault Circuit Interpreter   (GFCI)
Definition
 Monitors the current in hot and neutral wires    If reaches > 5mA then the circuit is interupted
Term
 Microshock
Definition
 Catheter or wire in the heart can deliver very high current density    100 microamps can induce V-Fib
Term
 Microshock Devices
Definition
 Isolate power supply from patients   Use very high impedence (small wires)    Deliver < 10 microamps   Ex. pacemakers
Term
 Electrosurgery
Definition
 High Frequencies: 500,000 - 1,000,000 Hz   Heat produced is inversley proportional to the area delivered    High Frequency (0.2-2 MHz) do not induce V-Fib   Must use large return pad
Term
 Bipolar Electrosurgical Devices
Definition
 Preferable and cause less induction   (all can cause problems with pacemakers and AICDs)
Term
 Unipolar Electrosurgical Devices
Definition
 Used with lowest possible settings   Used in brief periods as possible   DO NOT use within 15 cm of pacemaker or AICD
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