Safety Systems Flashcards
define voltage
the power potential behind the electrical energy
higher the voltage difference = greater the current moves through object
define current
flow of electricity from a point of higher voltage to lower; measured in amperes (Amp); flow of electrons from negative to positive
current = voltage / resistance
> 100mA bad for heart; >120mA potentially fatal
harmful effects of current depend on
- amount
- path
- time length
amount of voltage can handle depends on
total resistance of the body
- body fat
- fluid intake
- skin sweatiness (skin resistance= 1megohm dry; 1 kilohm when wet)
- where contact made
effect of ground wire connection
ground wire is the path of least resistance; if wire became exposed any current passing from wire to device would travel easier through ground wire than H.C.W
micro-shock occurrence and standards
monitors, ventilators
<0.01 mA for patient interface
<0.1 mA for instrument chassis
define transducer
a device that transforms energy from one type to another; pressure/mechanical energy measured via strain gauge
define voltmeter
a device that measure voltage aka the amount of electrons available to supply an electrical system
define ohmmeter
a device used to measure electrical resistance
1 volt/1 amp = 1 Ohm
define ammeter
a device used to measure the strength of an electrical current in ampere (Amp)
1 amp = 6.25 x 10^18 electrons passing per second
define resistance
the property of a conductor that is influenced by the conductors specific chemical composition, length and cross sectional area; measured in Ohms; opposite of flow
resistance proportional to length of wire
resistance inversely proportional to cross sectional area
define fuse
device that opens the circuit by melting/breaking in the presence of increased current flow; must be replaced when “blows”
define circuit breaker
device that responds to current flow above the rated capacity by opening a switch and “breaking the circuit”; must be reset by moving the switch to the “on” position (reusable device)
define AC / DC current
Alternating Current: a current which flows continuously and reverses direction, usually in periodic fashion of 60 Hz (cycles/second) .. alternates pos to neg, then neg to pos
Direct Current: a current that flows continuously in the same direction. Used in stand-alone generators or batteries
define battery
device that converts chemical energy to electrical energy using an anode, a cathode, and an electrolyte solution/gel
common battery voltages
most common: AA (1.5V); AAA (1.5V), C (1.5V), D (1.5V) and 9V
6 AA/AAA/C/D = 1 9V battery
C & D size: laryngoscopes
AA & 9V: o2 analyzers
define micro switch
aka pressure switch; device that senses pressure changes and transmits a signal to an electrical circuit (e.g. manifold alarm; o2 concentrator)
how does shock occur
since charges like to be in equilibrium; the excess electrons (static electricity) will jump onto a less electronegative person/object
define insulator
a non-conducting substance that is a barrier to electrical passage (e.g. rubber, wood, glass)
define conductor
a substance that allows the movement of electrons (flow of electricity/current) (e.g. water, metal)
principles for safe operation
- know the components
- ensure properly grounded
- keep one hand away from device to avoid passing current
- avoid jewelry
- tie hair back
- organize device/space
- not work on wet surfaces
- maintain equipment well
- ensure equipment stable
safety checks for equipment
- check condition of the equipment & dangers before use
- ensure grounded
- ensure appropriate sized fuse or circuit breaker used
- enclose: all electrical contacts, connectors, and switches
- replace wires with cracked insulation
- assess overheating
- ensure presence of sticker from Canadian standards association or Ontario hydro on each piece of equipment
- adhere to cord rules
what are the cord rules
- inspect cords and plugs
- make sure that plus has three prongs
- don’t use extension cords as permanent wiring
- never place cords under carpets, or near heat and water
WHMIS
Workplace Hazardous Material Information System
a comprehensive health and safety info on hazardous products intended for use, handling, or storage in Canadian workplaces
SDS and GHS
SDS: safety data sheets (formerly MSDS)
GHS: global harmonized system of classification and labelling of chemical (added 2015)
WHMIS purpose
- ensure safe and healthy environment
- ensure compliance with all relevant legislation
- prevent accidents
WHMIS employer responsibilities
- ensure products labelled/identified
- obtain material safe data sheets (SDS - all info regarding product)
- educate workers
WHMIS employee/student responsibilities
- participate in training
- know safety and health matters
- compliance with rules/regulations
- work safely
define physical hazards
based on the physical or chemical properties of the product
i.e. flammable gases, flammable aerosols, oxidizing gases, gases under pressure
define health hazards
based on the ability of the product to cause a health effect
i.e. acute toxicity, skin corrosion/irritation, serious eye damage/irritation, respiratory or skin sensitization, biohazards infectious materials
Canadian Standards Association (CSA)
who they? what do? what process?
Who
- volunteer not for profit organization; recommending body
Do
- standards research, development, education, advocacy; test equipment to standards
- give/withhold CSA approval
Process
1. incident occurs
2. CSA contacted
3. technical committee struck & subcommittees (education, technical testing etc)
4. standard created (draft to stakeholder for revisions)
5. final standard created & released
