E-Stim Basics & Pain Managment Flashcards
To have current there must be these 3 things
source, conductor, and driving force of electrons
Define current
net movement of charged particles along conductor
Define electromotive force
amount of electric potential in an electric field that drives charged particles
Low voltage is?
<150V
High voltage is?
> 500V
Define inductance
opposition to electric flow created by eddy currents when current passes through a wire
Define Capacitance
ability of a material to store electrical charge
Define Impedance
resistance+inductance+capacitance
Define Conductors
materials that offer little resistance
Define Resistors
materials that offer high resistance
Semiconductors
materials that offer neither low nor high resistance to current
Define Power
WATTS
Volts x Amps
Energy created by water flow depends on?
gallons/minute
pressure of the pipes
Ohm’s Law
V=IR
if we increase resistance we must increase voltage to move current
Define Parallel
when current flows through a circuit with multiple pathway to follow
Define series
when current flows through every resistor
List the 3 type of DC current
Continuous
Reversed DC current
Interrupted DC current
Define Continuous DC current
unidirectional flow of electrical charge for at least 1s
Define Reversed DC current
unidirectional flow of electrical charge for at least 1s and then changes polarity
Define Interrupted DC current
unidirectional flow of electrical charge for at least 1s then stops for 1s then resumes
Define AC current
a continuous bidirectional flow of electrical charge where each cycle lasts less than 1s
equal ion flow in each direction=no net charge
1cycle=1wavelength, wavelength inversely proportional to frequency
DC current is generally for?
Iontophoresis, Wound healing, Stimulating denervated nerves
AC current is generally for?
mm retraining, mm strengthening, pain modulation, functional training ie gait
Define pulsed current
Monophasic or Biphasic
Define the different types of Biphasic pulsed currents
symmetrical or asymmetrical
asymmetrical is either balanced or unbalanced
4 ways to describe WAVEFORMS
Number of phases
symmetry
balance
shape of waveform
4 ways to describe Amplitude
peak amp- max current reached for a single phase
peak to peak- max current reached from 1st phase to 2nd phase
RMS amp- for sine wave RMS, 0.707 of peak, 0.354 of peak to peak
average amp- mean volt under sine wave
8 ways to describe Time of current
Phase duration- beg of phase to end of phase
Pulse duration- beg of pulse to end of pulse
Rise time- beg of phase to peak of phase
Decay time- peak of phase to end of phase
Interpulse duration- end of pulse to beg of next pulse
Intrapulse duration- end of phase to beg of next phase
Period- time it takes to complete one pulse
Frequency- 1/period
4 ways to modify current
amp mods
pulse duration mods
frequency mods
ramp mods
Timing mods (Burst)
Burst duration
Interburst interval
Burst frequency
Size of electrodes
smaller electrodes=denser
Placement of electrodes
closer to each other=more superficial density
farther from each other=more deeper density
Tap key electrode
to identify motor points
stimulate small muscles
Define IFC
interferential currents of medium frequency (1,000-10,000) unmodulated sinusoidal waves that cross
Define beat frequency
net of 2 different carrier frequencies
Define constructive IFC
originate at same time and summate
Define destructive IFC
originate at different time and cancel out
Define heterodyne
blending of waves constituting and destructively
Define constant bipolar
both carriers are fixed
Define quadripolar
one is fixed other has varied frequency=sweep frequency to minimize accommodation
Define scanning quad vector
move entire petal of stim to cover more treatment area
Define stereodynamic
3 distinct circuits that blend and create a distinct wave
Define High Volt Pulsed current
twin peak monophasic pulsed current that rises instantly and declines exponentially
What is the typical pulse duration and frequency of HVPC
pulse duration=100-200
frequency=1-200pps
Strength duration curve relationship between voltage and pulse duration
increase volt, decreased pulse duration
Tissue impedance and HVPC
HVPC=low capacitance=low impedance=more comfortable
Typical Parameters of Russian Currents
frequency=2,500 burst duration=10ms interburst interval=10ms burst frequency=50/s On:Off=10/50 Duty cycle start from 100% and move down with pt. comfort
Russian currents characteristics
painless involuntary contraction training
increase current amp for deeper motor neurons
can painlessly stim larger pools of type II motor units for voluntary max mm. force
Strength-duration curve between amp, pulse duration, and motor/sensory neurons
low current amp, low pulse duration to stim A Beta, A delta
high current amp, high pulse duration to stim A Alpha, A gamma
higher yet current, longer pulse duration to stim pain transmitting C-fibers
Define Rheobase
minimal current (with long pulse duration) needed to AP
Define Chronxaie
minimal duration to stimulate tissue at 2x of rheobase
Current and pulse duration controlling superficial and deep fibers in mixed nerves
current and pulse duration just enough to reach threshold
large superficial fibers
medium superficial fibers, large deeper fibers
small superficial fibers, medium deeper fibers
TENS Conventional
high frequency, low pulse duration, lower current just enough to feel tingling
only when unit is on, can be effective 24 hours
100-150pps
50-80 microseconds
Low rate TENS
low frequency, high pulse duration, higher current just enough to feel muscle contraction
effective for 4-4/12 hours, after 20 minutes
2-10pps
100-200 microseconds
Noxious TENS
can use high or low frequency
opiod,seratonin,muscarinic mediated
5pps or 80 pps
up to 1,000 microseconds or 1s
amp: 2x motor threshold
IFC parameters for pain management
to stim sensory
50-120pps
to stim motor
30-50pps
1pps to acustim pain relief
IFC Indications
pain of known origin
muscle relaxation to increase blood flow and decrease edema
IFC effect
inc pain threshold
mm contraction
mm pump
Burst TENS parameters
10pps
200-300 microseconds
HVPC parameters for pain management
to stim sensory
80-120pps
to stim motor
30-60microseconds
2-4 for motorpain
