Intro To Electrotherapy

Question 1

Pulse Characteristics

Answer 1

Waveform
Duration (pulse/phase)
Amplitude
Pulse/phase charge
Frequency

Question 2

Pulse: Waveform Types

Answer 2

Mono/Biphasic
Symmetrical/asymmetrical
Balanced/unbalance
Shape

Question 3

Pulse/Phase Duration

Answer 3

Phase duration: time elapsed from beginning to end of one phase (cross “0”)
Pulse duration: time elapsed from beginning to end of all phases

Question 4

Current Amplitude

Answer 4

Peak: each phase
Peak to peak: entire pulse

Question 5

Pulse/Phase Charge

Answer 5

Two pulses with different amplitudes and durations, but have the same pulse/phase charge
Ex: 50mA x 100mircos / 25mA x 200 micros

Question 6

Nerve response factors

Answer 6

Size and location!

Question 7

Strength-Duration Curve

Answer 7

Shows which nerve type will get activated with the estim first
(sensory - motor - noxious)

Question 8

Pulse Frequency

Answer 8

Defined: time elapsed from one point in one waveform to the identical spot on the next waveform (pps)
Time/ period
Increased frequency will feel more continuous

Question 9

On/Off times

Answer 9

Pain/ edema (1:1)
Strengthening (1:5)
Functional (controlled via trigger)

Question 10

Contraindications

Answer 10

Cardiac problems (pacemakers/ICD)
Electronic devices
Carotid sinus
Larynx
Pregnancy (low back/abs)
Broken/damaged skin
DVT
CA
Recently radiated tissue
Chest (cardiac issues)
Neck/head (seizures_
On or near eyes

Question 11

Precautions

Answer 11

Open skin lesions
Skin conditions
Open epiphysis
Mental status
Reduced sensation
Allergies
Metal implants
Cognitive/communications impairments

Question 12

Charge

Answer 12

Coulombs
(+) cations
(-) anions

Question 13

Current

Answer 13

Movement of charged particles through a conductor (measured in amperes)

Question 14

Voltage

Answer 14

Potential difference or electromotive force; driving force that mess charged particles move

1v = 1 amp of current with 1 ohm of resistance

Question 15

Resistance

Answer 15

Opposition to current

I = V/R

Question 16

Ohms Law

Answer 16

V = I x R
I = V/R

Question 17

Resistors in series

Answer 17

V = I(R1 + R2 +R3)
Total = more than the individual

Question 18

Resistors in Parallel

Answer 18

1/Rtotal = 1/R1 + 1/R2 + 1/R3

Total resistance is typically less than individual

Question 19

Biological Resistance in the body

Answer 19

Skin and fat are in series
Nerve/muscle/bone are in parallel
The nerve gets the most electronic stimulation due to it having the smallest resistance

Question 20

100 v with 4.467 kColumbs (R), find I

Answer 20

100V/4467 Columbus (convert)
0.02 amps OR 20 miliamps

Question 21

What happens to current flow when electrodes on a patient touch each other?

Answer 21

Increase in current and voltage (chemical burn)

Question 22

What happens to current flow when there is a break in the skin?

Answer 22

Decreased resistance, focus going to cut (chemical burn)

Question 23

What happens to current flow with dry skin or dry electrodes?

Answer 23

Decreased conduction and increased resistance

Question 24

Direct current

Answer 24

Uninterrupted uni-directional flow

Question 25

Alternating current

Answer 25

Uninterrupted bi-directional flow

Question 26

Pulsation current

Answer 26

Space between flow, mono or biphasic

Question 27

DC application

Answer 27

Correctly applied: Therapeutic flow of ions, local increase in blood flow to restore PH
Excess application: Blistering, chemical burns, basic reaction

Flow: Cl- near anode and Na+ near Cathode

(+) side: more acidic, harden tissues? Vasoconstriction, decreased excitability
(-) side: more basic, softens tissue?, vasodilation, increased nerve excitability

Question 28

AC appplication

Answer 28

Zero NET current flow, no chemical effects

Can be (uninterrupted) bidirectional OR pulsed current (Interrupted)

Question 29

“Russian” current

Answer 29

Burst modulated AC
Current with breaks
Used for strengthening