THERAPEUTIC INTERVENTIONS Practice Exam
#2 Questions and Answers Latest 2025 Top Rated A+
disadvantages of constant current stimulators
1. resistance increases (electrode is loose) --> voltage
automatically increases
2. skin burns due to current density
2 characteristics of constant voltage stimulators
1. set up in volts
2. current varies as resistance changes
disadvantage of constant voltage stimulators
1. decreased resistance, current intensity increases which will
increases sensation causing discomfort
common shapes of waves
- sine
- triangular
- square
what is the phase of a wave described as
the portion of the current that rises above or below the baseline
currents can have either 2 types of phases, what are they
1. monophasic (1 phase)
2. biphasic (2 phase)
what are the characteristics of a direct current
1. monophasic
2. continuous unidirectional flow of charged particles
3. positive or negative
direct currents can traditionally be called
galvanic stimulators
what is the one true device that has a true direct current
iontophoresis (turn on and stays on)
characteristics of alternating currents
1. biphasic
2. bidirectional flow of charged particles
,3. symmetrical or asymmetrical
4. polarity is not an issue unless asymmetrical (zero net charge)
characteristics of pulsatile currents
1. unidirectional or bidirectional flow of charged particles that
ceases for a period of time
2. used clinically
if a pulsatile current has a monophasic pulse then
we use pulses per second (pps)
if a pulsatile current has a biphasic pulse then
we use hertz (Hz)
what is amplitude
magnitude of current or voltage with reference to the baseline
amplitude is also called
intensity
amplitude is measured in
microamps, milliamps, volts
"peak to peak amplitude" means
difference in displacement between the largest amplitude above
the baseline and the largest amplitude below the baseline
what is pulse rate
frequency of the pulsatile current
pulse rate is also called
frequency
what is pulse rate measured in
- pps
- Hertz
what is pulse width
the elapsed time of a wave from beginning to end
where is the intrapulse
within a pulse
what is another name for pulse width
pulse duration
what are the pulse width options of machines
1. preset (40-50 microsecond) ie: HVPC
2. variable (typical of TENS)
, 3. automatic variable: reduces adaption of nerves of time (pain
protocol)
when does intrapulse interval occur
in high voltage pulsed current generator where waveform is "twin
peaked pulsed current" (one pulse)
what is average current
amount of current delivered to the tissue per cm^2
what is safe current
1-4 mA/cm^2
what 3 things will affect average current
1. pulse amplitude
2. frequency
3. duration
higher frequency =
more current
what is interpulse interaval
period of time between pulses where there is no current flow
interval decreases as
- pulse width increases
- pulse frequency increases
what is a burst
finite series of pulses delivered at an identified frequency and
delivered as a single
what is another name for burst
pulse train
what are bursts measured in
bursts per second (bps)
what is duty cycle
time on/(time on + time off)
what are the 3 different types of electrodes
1. carbon impregnated
2. metal plate
3. self-adhering single use
what are the characteristics of carbon impregnated
electrodes (+ and -)
#2 Questions and Answers Latest 2025 Top Rated A+
disadvantages of constant current stimulators
1. resistance increases (electrode is loose) --> voltage
automatically increases
2. skin burns due to current density
2 characteristics of constant voltage stimulators
1. set up in volts
2. current varies as resistance changes
disadvantage of constant voltage stimulators
1. decreased resistance, current intensity increases which will
increases sensation causing discomfort
common shapes of waves
- sine
- triangular
- square
what is the phase of a wave described as
the portion of the current that rises above or below the baseline
currents can have either 2 types of phases, what are they
1. monophasic (1 phase)
2. biphasic (2 phase)
what are the characteristics of a direct current
1. monophasic
2. continuous unidirectional flow of charged particles
3. positive or negative
direct currents can traditionally be called
galvanic stimulators
what is the one true device that has a true direct current
iontophoresis (turn on and stays on)
characteristics of alternating currents
1. biphasic
2. bidirectional flow of charged particles
,3. symmetrical or asymmetrical
4. polarity is not an issue unless asymmetrical (zero net charge)
characteristics of pulsatile currents
1. unidirectional or bidirectional flow of charged particles that
ceases for a period of time
2. used clinically
if a pulsatile current has a monophasic pulse then
we use pulses per second (pps)
if a pulsatile current has a biphasic pulse then
we use hertz (Hz)
what is amplitude
magnitude of current or voltage with reference to the baseline
amplitude is also called
intensity
amplitude is measured in
microamps, milliamps, volts
"peak to peak amplitude" means
difference in displacement between the largest amplitude above
the baseline and the largest amplitude below the baseline
what is pulse rate
frequency of the pulsatile current
pulse rate is also called
frequency
what is pulse rate measured in
- pps
- Hertz
what is pulse width
the elapsed time of a wave from beginning to end
where is the intrapulse
within a pulse
what is another name for pulse width
pulse duration
what are the pulse width options of machines
1. preset (40-50 microsecond) ie: HVPC
2. variable (typical of TENS)
, 3. automatic variable: reduces adaption of nerves of time (pain
protocol)
when does intrapulse interval occur
in high voltage pulsed current generator where waveform is "twin
peaked pulsed current" (one pulse)
what is average current
amount of current delivered to the tissue per cm^2
what is safe current
1-4 mA/cm^2
what 3 things will affect average current
1. pulse amplitude
2. frequency
3. duration
higher frequency =
more current
what is interpulse interaval
period of time between pulses where there is no current flow
interval decreases as
- pulse width increases
- pulse frequency increases
what is a burst
finite series of pulses delivered at an identified frequency and
delivered as a single
what is another name for burst
pulse train
what are bursts measured in
bursts per second (bps)
what is duty cycle
time on/(time on + time off)
what are the 3 different types of electrodes
1. carbon impregnated
2. metal plate
3. self-adhering single use
what are the characteristics of carbon impregnated
electrodes (+ and -)
