Safety Systems

Question 1

define voltage

Answer 1

the power potential behind the electrical energy

higher the voltage difference = greater the current moves through object

Question 2

define current

Answer 2

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

Question 3

harmful effects of current depend on

Answer 3

1. amount
2. path
3. time length

Question 4

amount of voltage can handle depends on

Answer 4

total resistance of the body
- body fat
- fluid intake
- skin sweatiness (skin resistance= 1megohm dry; 1 kilohm when wet)
- where contact made

Question 5

effect of ground wire connection

Answer 5

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

Question 6

micro-shock occurrence and standards

Answer 6

monitors, ventilators

<0.01 mA for patient interface
<0.1 mA for instrument chassis

Question 7

define transducer

Answer 7

a device that transforms energy from one type to another; pressure/mechanical energy measured via strain gauge

Question 8

define voltmeter

Answer 8

a device that measure voltage aka the amount of electrons available to supply an electrical system

Question 9

define ohmmeter

Answer 9

a device used to measure electrical resistance

1 volt/1 amp = 1 Ohm

Question 10

define ammeter

Answer 10

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

Question 11

define resistance

Answer 11

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

Question 12

define fuse

Answer 12

device that opens the circuit by melting/breaking in the presence of increased current flow; must be replaced when “blows”

Question 13

define circuit breaker

Answer 13

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)

Question 14

define AC / DC current

Answer 14

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

Question 15

define battery

Answer 15

device that converts chemical energy to electrical energy using an anode, a cathode, and an electrolyte solution/gel

Question 16

common battery voltages

Answer 16

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

Question 17

define micro switch

Answer 17

aka pressure switch; device that senses pressure changes and transmits a signal to an electrical circuit (e.g. manifold alarm; o2 concentrator)

Question 18

how does shock occur

Answer 18

since charges like to be in equilibrium; the excess electrons (static electricity) will jump onto a less electronegative person/object

Question 19

define insulator

Answer 19

a non-conducting substance that is a barrier to electrical passage (e.g. rubber, wood, glass)

Question 20

define conductor

Answer 20

a substance that allows the movement of electrons (flow of electricity/current) (e.g. water, metal)

Question 21

principles for safe operation

Answer 21

1. know the components
2. ensure properly grounded
3. keep one hand away from device to avoid passing current
4. avoid jewelry
5. tie hair back
6. organize device/space
7. not work on wet surfaces
8. maintain equipment well
9. ensure equipment stable

Question 22

safety checks for equipment

Answer 22

1. check condition of the equipment & dangers before use
2. ensure grounded
3. ensure appropriate sized fuse or circuit breaker used
4. enclose: all electrical contacts, connectors, and switches
5. replace wires with cracked insulation
6. assess overheating
7. ensure presence of sticker from Canadian standards association or Ontario hydro on each piece of equipment
8. adhere to cord rules

Question 23

what are the cord rules

Answer 23

1. inspect cords and plugs
2. make sure that plus has three prongs
3. don’t use extension cords as permanent wiring
4. never place cords under carpets, or near heat and water

Question 24

WHMIS

Answer 24

Workplace Hazardous Material Information System

a comprehensive health and safety info on hazardous products intended for use, handling, or storage in Canadian workplaces

Question 25

SDS and GHS

Answer 25

SDS: safety data sheets (formerly MSDS) GHS: global harmonized system of classification and labelling of chemical (added 2015)

Question 26

WHMIS purpose

Answer 26

1. ensure safe and healthy environment 2. ensure compliance with all relevant legislation 3. prevent accidents

Question 27

WHMIS employer responsibilities

Answer 27

1. ensure products labelled/identified 2. obtain material safe data sheets (SDS - all info regarding product) 3. educate workers

Question 28

WHMIS employee/student responsibilities

Answer 28

1. participate in training 2. know safety and health matters 3. compliance with rules/regulations 4. work safely

Question 29

define physical hazards

Answer 29

based on the physical or chemical properties of the product i.e. flammable gases, flammable aerosols, oxidizing gases, gases under pressure

Question 30

define health hazards

Answer 30

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

Question 31

Canadian Standards Association (CSA) who they? what do? what process?

Answer 31

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