Intro Electrotherapy Flashcards
Charge
- No of free electrons that atoms lose or gain
Gaining electrons makes an atom more
negative
positive ion
cation
negative ion
anion
cations are attracted to
cathodes
cathodes are what charge
negative
anions are attracted to
anodes
anodes are what charge
positive
unit of measurement for charge
Coulumb
Current
- Movement of charged particles
- Response to an applied electric field
- Opposite flow of electrons
unit of measurement for current
ampere (1 C/s)
mA for stimulators
voltage
- Electromotive force or electrical potential difference
- Diff between positive and negative charges
- Driving force that makes particles move
Resistance
- Opposition to movement of DC
- Ohm
Ohm’s law
I = V/R
impedance
- Opposition to movement of AC
forms of resistance
○ Circuit stimulator (resistive, capacitive, inductive)
○ Skin surface (resistive, capacitive)
Conductance
- Ease with which a material allows current to flow
unit of measurement for conductance
○ Mho
○ Siemens
Capacitance
- Ability to store charge using electrostatic field
unit of measurement of capacitance
Farad
Capacity =
charge/voltage
Inductance
Ability to store electrical energy through electromagnetic field
unit for inductance
henry
Power source can be
- Batt operated or direct line
pros & cons of batt power source
○ Small stimulator
○ Portable
○ Not reliable source
○ Limited options
pros & cons of direct line power source
○ Stable power
○ More controls
○ Not portable
function of output amplifier
- Setting intensity
between constant current and constant voltage which is more common
constant current
duration for pain relief
20 mins
duration for atrophy
10 mins
duration for re-education
1-15 mins
pro of constant voltage
- Lower internal resistance <50 ohm
- Auto reduction of current (safe)
