wave form
shape of an electrical current
monophasic wave (=dc current, one direction)
a unidirectional flow of charged particles. A current flow in one direction for a finite period of time in a phase. It has either a positive or negative charge.
biphasic wave (alternating current)
a bidirectional flow of charged particles. This type of wave form is illustrated as one-half of the cycle above the baseline and the second phase below the baseline. One complete cycle (2 phases) equals a single pulse
polyphasic wave (poly= mini burst)
modified to produce three or more phases in a single pulse. The waveform in medium frequency may be Russian or interferential current.
positive
monophasic is only _______________, dc current
positive and negative
biphasic is _____________________________- alternating current
direct wave from (galvanic)
-monophasic, rectangular current
-pure DC
-used for iontophoresis
-either stays positive or negative the whole time
interrupted DC wave form
-monophasic, rectangular, pulsed
-unidirectional flow caused by rapid and repeating turning on and off of the current
-DC, have a pause. DC, have a pause.
sinusoidal wave form
-biphasic, symmetrical, balanced, sinusoidal
-pure AC
-basic wave form of interferential and Russian wave forms.
goes up and down = biphasic -alternating current
faradic wave form
-biphasic, asymmetrical, unbalanced, spiked
-induced asymmetrical AC
-alternating
ramp up
the time during which the intensity of an electrical charge increases
plateau
the time during which pulses remain at maximum preset intensity
ramp down
the time during which the intensity of an electrical charge decreases
time on
the time during which current flows from the beginning to the end of a surge
time off
the time during which current does not flow; the time between surges
rectangular/modified square
-monophasic, rectangular, pulsed
-similar to interrupted DC but modulated from AC input
biphasic
biphasic, symmetrical, balanced, rectangular, pulsed
twin pulse wave form
monophasic, pulsed, twin spiked
interferential wave form
symmetrical, sinusoidal, high -frequency AC
-two channels with different frequencies used simultaneously
Russian wave form
polyphasic, symmetrical, sinusoidal, burst
4
interferential always uses ___ pads
2
premodulated waveform is only going to use ____ pads. We use these for pain control
strengthening
Russian and biphasic are used for ____________
current modulation
manipulating, regulating, and adjusting of the input current to create a variety of specific output wave forms.
input currents are modulated (you can adjust parameters):
-pulse rate
-pulse width
-amplitude
electrodes
devices attached to the terminals of an electrical stimulator unit through which current enters and leaves the body
electrodes
come in a variety of shapes, sizes, and materials
-metal-sponge electrodes
-carbon-or silicon- impregnated rubber electrodes (sponge, paper towel, or conducted gen interface)
-adhesives backed carbon- or silicon- impregnated electrodes
metal sponge electrodes
a thin metal plate attaches to the wire from the terminal of this kind of electrode. A wet sponge is placed between the metal plate and the skin to increase the conductivity between the two. These are held in place with a flexible rubber belt of a sandbag
carbon (or siligon-impregnated) rubber electrodes
carbon or silicon is added to the rubber, which is an insulator, so that it becomes a conductor in this kind of electrode. A wet sponge, a wet paper towel or conductive gel is placed between the rubber plate and skin to increase the conductivity between t
adhesive backed (or silicon- impregnated) rubber electrodes
in this type of electrode, adhesive is used in place of the sponge or paper towel and rubber belt or sandbag. these are quicker and easier to apply but more expensive than other systems. They were intended to be single-use, disposable electrodes, but most
Current density
a measure of the quantity of charged ions moving through a particular cross-sectional areas of an electrode. If the electrodes through which the current flows are of equal size, the current density will be equal. If on of the electrodes is bigger than the
stronger
smaller electrodes are _____________ because they have a smaller area to cover and don't have to spread out as much.
motor units
size and placement of the electrodes determine the number of ______________ that are stimulated.
single muscle
smaller electrodes are for __________________ stimulation
multi muscle
larger electrodes are for ____________ stimulation
current density
smaller electrode has a greater _______________ under the electrode.
active electrode
electrode under which the current density is great enough to elicit the desired response
dispersive electrode
electrode under which current density is not great enough to elicit the desired response
-larger than the active electrode.
longitudinally
mm conducts electricity 4X better __________than transversely
parallel
electrodes should be applied ___________ to mm fibers rather than perpendicular to them.
motor point
the place where a given amount of current will elicit the greatest muscular contraction. It is the point where the motor nerve enters the mm, usually located at the beginning of the mm belly
muscle
motor points are located by trial and error, by looking for a good sharp mm contraction while moving the electrode over the mm
anatomical variation
charts can help identify motor point, but there is a certain amount of ___________________________ in location
trigger point
a localized area of the body that is extremely sensitive to palpation, e-stim, and ultrasound.
bipolar technique
in this electrode placement technique, electrodes from the 2 terminals are of equal size, resulting in essentially equal current density under them
unipplar technique (monopolar)
In this electrode placement technique, electrodes from the 2 terminals are unequal size, thus creating active and dispersive electrodes. There may be multiple active electrodes, all coming form the same terminal as long as their aggregate size is less tha
quadripolar technique
in this electrode placement technique, 4 electrodes of = size are used, a pair from each of the 2 channels. Generally, they crisscross the target tissue.
bipolar placement
which placement is this?
unipolar placement
which placement is this?
quadripolar placement
which placement is this?