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78 Cards in this Set

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Theory of electrical modalities
1) charged particles move from an area of high concentraction to areas of lower concentration

2) as an electrical force is applied to particles, they can be propelled from higher energy states to lower ------> Action potential
Unit of measure for CURRENT
amps, mA, or uA
How many coulumbs in 1 amp?
1 coulumb
electromotive force needed to produce a flow of electrons from high potential to low potential?
volt
materials that FACILITATE movement of electrons
conductors
materials that RESIST movement of electrons
insulators
opposition of electron flow in a conductor is called?
resistance
=electrical impedence
Unit of measure for resistance?
ohm
Ohm's Law
-current in an electrical circuit is DIRECTLY proportional to VOLTAGE and INVERSELY proportional to RESISTANCE
Equation for current in Ohm's Law
current = volt/resistance
electrical power (watts) = ?
voltage X amps
PT modalities fall within what 4 Hz ranges?
1) HIGH
100,000-3,000,000 Hz

2) MEDIUM
2,000-10,000 Hz

3) LOW
1-2,000 Hz

4) ULTRA - LOW
<1 Hz
Which modalities fall into the HIGH frequency range?
1) diathermy
2) IR
3) UV
4) US
Which modalities fall into the MEDIUM frequency range?
1) interferential
2) Russion stim
Which modalities fall into the LOW frequency range?
1) Biphasic
2) TENS
3) HVPC
4) LVPC
5) Microcurrent
Which modalities fall into the ULTRA-LOW frequency range?
1) microcurrent
What are the 3 types of current that electrotherapeutic modalities can generate?
1) AC
2) DC
3) Pulsed
AKA for AC current?
biphasic
AKA for DC current?
monophasic
Modalities that generate an AC current (biphasic)?
1) interferential
2) microcurrent
3) TENS
Modalities that generate a DC current (monophasic)?
1) LVG
2) HVPC
3) LVPC
4) Microcurrent
Modalities that generate a Pulsed current?
1) HVPC
2) LVPC
3) Microcurrent
4) TENS
-unidirectional flow of electrons

-can be set at + or -
monophasic
-poles are switched

-flow of electrons is reversed over and over
biphasic
-can be mono or biphasic

-interuption of current or flow
pulsed
What are the 3 types of waveforms?
1) sinusoidal
"arch-like"

2) rectangular

3) triangular
Intensity of current?
amplitude
-individual waveform

-may comprise of 1 or 2 phases

-portion which rises above or goes below the baseline
pulse
gaps in a pulsed current are called?
interpulse interval
length of time that current is flowing?
pulse duration
period of time from start of one pulse to the beginning of the next?
pulse period
amount of electricity being delivered to the patient during each pulse?
pulse charge
type of current where pulse and phase charge are equal?
monophasic
asymmetric biphasic waveform?
faradic wave
Muscular and nervous tissue respond to the impulses depending upon what 3 things?
1) Hz
2) length of time b/t pulses
3) modulation
any change in duration or magnitude of a pulse?
modulation
amplitude of wave stays constant for a long period of time?
continuous modulation
What is used with monophasic current to produce a build up of ions?
continuous modulation
What causes tissue hardening?
at (+) pole, negative ions produce an ACID rxn
What causes tissue softening?
at (-) pole, an ALKALINE rxn
Tissue hardening and softening by ions is termed?
medical galvanism
-current flows for some time then turned off for sometime

-used to re-educate or strengthen muscles and improve ROM
interrupted modulation
pulsed current for a short duration followed by interuption for a short duration usually milliseconds?
burst modulation
-amplitude of wave is increased then leveled off then decreased gradually

-time usually thirds
ramped/surged modulation
-interrupted modulation using 2 channels

-alternating contraction flextion/extension
alternating/recirocating/switch rate modulation
+ pole is called?
anode
(-) pole is called?
cathode
negatively charged ions attracted to anode?
anions
positively charged ions attracted to cathode?
cations
Coulomb's Law
-unlike charges attract, while like charges repel
What are the 2 types of electrical circuits?
1) series circuit

2) parallel circuit
-only 1 path for the ions to flow from one electrode to the other
series circuit
-more than one pathway is provided for current flow
parallel circuit
Which part of a circuit has a large amount of electrons?
cathode
Current will seek out the path of lease resistance.
Kirchoff's Principle
Which circuit is created when you put electrods on the skin?
series circuit
Circuit where current travels the path of least resistance?
parallel circuit
Tissue conductivity is relative to what?
water content

*skin = high imedance
*nerves = low impedance, but myelin is fat therefore high impedance
Conduction of muscles
muscles conduct 4X better longitudinally than transversely
Conductivity relative to resistance?
High resistance = poor conductivity
Physiological effects of electrical current?
1) create ms contraction

2) stimulate sensory nerves to decrease pain

3) creates polar effects in tissues to stimulate or alter healing

4) create electrical field to drive (+) ions into skin
electrical current that creates electrical field to drive (+) ions into skin is called?
ionophoresis
What allows the cell membrane to form potential differences b/t inside and outside the cell?
Na/K pumps
What creates a resting membrane potential?
Na pumped OUT

K pumped IN
impulse required potential to be reduced below threshold level
action potential
What is needed for an action potential to occur?
-impulse needs to be STRONG enough and LONG enough for ions to be pushed thru MB exceeding pump capacity
neutralizing cell membrane potential
depolarization
membrane incapable of depolarization.

pumps are actively trying to re-establish resting membrane potential
absolute refractory period

-about 0.5 usec
another action potential can be produced if stimulus is strong enough
relative refractory period
membrane becomes partially insensitive due to repeated stimulation before full restoration of membrane resting potential
Wedensky inhibition
contraction magnitude is increased when frequency of depolarization increases.
summatino of contraction
constant non-varying muscle contraction is called?
tetany
Hz for tetany?
20-85 Hz
Muscle contraction occurs under the _______.
cathode
Increasing the intensity of a stimulus will result in what?
deeper penetration
When electrodes are placed further apart, how does the current travel?
deeper
Pulsed/interrupted modulation should be done at a ratio of _____.
1:3
Which waveform may not be a good idea due to muscle accommodation?
ramped waveform