Week 5 Electro Therapy Flashcards
(71 cards)
1
Q
4 Principles of Electricity
A
- two types of charges + and -
- Like charges repel while opposites attract
- Charges are neither created nor destroyed
- Charges can be transferred from 1 object to another
2
Q
Cathode=
A
negatively charged poll
3
Q
Anode=
A
Positively charged poll
4
Q
Voltage =
A
Force of attraction or repulsion created by an electrical field represents potential energy
- Greater the force the greater the potential energy
5
Q
Voltage in the body is created by….
A
uneven distribution of charged particles
6
Q
If charges are equal on each side of the membrane the will have (blank) voltage
A
No
7
Q
Conductors of the body
A
water/body fluids
nerves
muscle tissue
8
Q
Insulators of the body
A
Fat
9
Q
Current =
A
The movement of ions/electrons in repones to voltage force
- Ampere
- Milliamperes
Microcurrent
10
Q
Ohm’s Law
A
I= V/R
Current= Voltage/resistance
- More resistance to current the less current there will be
11
Q
Capacitance
A
Current flowing in an insulated area with high resistance will slow and charge will start to store in that area
12
Q
Impedance
A
Resistance to the flow of alternating current
- Clinically gels and adhesives conductive agents help decrease impedance
13
Q
Areas of high fact act as insulators and will (blank) electrical stimulation trasnmissions
A
Impede
14
Q
Waveforms
A
A depiction of the characteristics that describe a current
15
Q
Direct Current
A
- Continuous unidirectional flow of electrons for at least 1 second
Types of direct current= interrupted, reversed, interrupted/reversed
- Clinical considerations= one electrode positive and one electrode negative
-Clinical uses= used less frequently in rehab than other current types, iontophoresis, wound care
16
Q
Alternating Current
A
- Uninterrupted bidirectional flow of electrons, must change direction at least once per second
- Frequency= rate AC current changes direct
- Cycles per second= hertz (Hz)
- clinical uses= use of pure sinusoidal AC current is not common
17
Q
Russian Current
A
Burst of modulated AC current
18
Q
Interferential Current
A
Amplitude modulated AC current
19
Q
Pulsed Current
A
Unidirectional or Bidirectional flow of electrons that periodically ceases for a short time period, the interphase/interpulse interval before the next event or pulse
20
Q
Burst PC
A
2 or more pulses separated from the next series of pulses
- Burst frequency= frequency bursts are generated
- Carrier Frequency= frequency of underlying waveform
21
Q
Duty Cycle
A
on-time/total time (on time + off time) x 100%
Examples:
on time 10 seconds, off time 40 seconds (10:40) duty cycle = 10/10+40 x100% = 20%
22
Q
Phase charge
A
23
Q
Pulse Charge
A
Charge within a single pulse
24
Q
What are the 3 commonly used currents that result in a net + or - charge
A
- direct current
- monophasic pulsed current
- Asymmetrical unbalanced biphasic current
25
What are the electrothermal effects of electrical current in body tissue?
- As charged particles flow through a conductor friction occurs as they meet resistance and produce kinetic energy which produces heat
26
T/F there is more of a concern with DC than a concern for AC or pulsed current
True
27
What are the levels of response to Electrical Stimulation?
1st= sensory- 1st perception of electrical stimulus: stimulation of A-beta sensory fibers in the superficial dermis
2nd= motor- increased electrical stimulus causes A- alpha motor neurons to depolarize and elicit a motor response: motor response proportional to intensity of stimulus : initial motor response may appear ass a muscle twitch or fasciculation
3rd= Noxious- further increase in intensity or duration beyond that capable of eliciting a sensory or motor response stimulates pain receptors - A-delta and C fiber are excited and elicit noxious sensation : sometimes used for therapeutic purpose
28
Action potentials are........
All or nothing
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High Volt Pulsed Current (HVPC)
- continuous, reciprocating, or surge, monophasic
- used for pain modulation, tissue repair, wound healing
30
Interferential Current (IFC)
- quadripolar or bipolar set-ups available on most devices
- used primarily for pain modulation
31
Russian Current (Burst Modulation) is used for....
Variation of AC used for strengthening muscles
32
Low-Intensity DC (microcurrent) is used for
- Does not stimulate sensory/motor nerves
- Used for tissue repair, wound healing
33
Symmetrical/Asymmetrical Biphasic PC used for
- used for muscle stimulation, pain modulation
- Little to no difference in effectiveness for muscle stimulation using symmetrical biphasic PC vs. Russian
34
Voltage and current are (blank) proportional
directly
35
Constant Current
Maintains a constant flow of current by modulating voltage
- may be a better choice for treatment as intensity is maintained closer to the level required for therapeutic purposes
36
Disposable Electrodes
- many shapes and sizes, reusable for multiple applications
- 18-20 applications
37
Flexible electrodes
carbonized silicon rubber, reusable, pliable with good conductivity
38
Metal Electrodes
wet sponge between metal and tissue, great conductor, lack flexibility
39
Large Electrodes
- Lower current density= more comfortable
- appropriate for larger muscles and treatment areas
- may cause overflow to non-target areas if too large
40
Smaller Electrodes
- Higher current density
- high levels of stimulation intensity with small electrodes may cause uncomfortable burning sensation
- appropriate for smaller muscles and treatment areas
41
Wider electrode spacing allows....
- allows for increased current density
- allows currents to travel deeper and reach deeper tissues
- -> reach motor nerves and muscles
--> activate more motor units in NMES
--> activate more sensory fibers in TENS
42
Electrode Configurations
- Bipolar= 2 active electrodes
- Monopolar= 1 active
- Quadripolar= 4 active
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Bipolar Electrode Configuration
- most common
- commonly used for muscle activation/ pain modulation
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Quadripolar Electrode Configuration
- 4 electrodes of 2 separate circuits over target tissue
- Interferential current for pain modulation most commo application
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NMES
- Neuromuscular stimulation
- for muscle strengthening
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TENS
-Transcutaneous nerve stimulation
- for pain modulation
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FES
- functional electrical stimulation
- Neuro re-education or functional training
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CONTRAINDICATIONS for ES and Iontophoresis
1. The trunk or heart region of patients with demand-type pacemakers or implantable cardioverter defibrillators
2. carotid bodies
3. patients with phrenic nerve or urinary bladder stimulators
4. Areas of known peripheral vascular disease, including arterial or venous thrombosis or thrombophlebitis
5. the phrenic nerves, eyes or gonads
6. Areas of active osteomyelitis
7. areas of hemorrhage
49
Pregnancy ES
- electrical effects of electrical stimulation on the fetus or uterus are not clearly known
--> Caution is recommended
- Unknown effects of ES on fetal health should be disclosed to the patient
50
PRECAUTIONS for ES and Iontophoresis
- Patients without intact sensation
- unable to communicate or with compromised mental or cognitive ability
- with cardiac dysfunction
- Over neoplasms (active or previous)
- Electrodes should not be placed over: compromised skin , tissue vulnerable to hemorrhage or hematoma , cervical or craniofacial regions in patients who have a history of CVA or seizures
- do not use ES within 5 yards of diathermy units or other sources of electromagnetic radiation
51
What is Iontophoresis?
Using electrical current to drive medication through the skin to the target tissue
52
Clinical Uses for Iontophoresis
- soft tissue inflammatory conditions
- neuralgia
- edema
-ischemic skin ulcers
hyperhidrosis
- plantar warts
- calcific tendonitis
- scar tissue
- other connective tissue disorders
53
Physiology of Iontophoresis: Electroporation
- increases in polarity of superficial skin in response to ES allows medication to enter the target tissue more easily
53
Physiology of Iontophoresis: Electromigration
- Using ES to move charge ions into the target tissue
- Like charges repel, opposite charges attract
53
Physiology of Iontophoresis: Electroosmotic flow
- when positive and negative electrodes applied to skin, ions of positive charge in the extracellular fluid attracted to the cathode and ions of negative charge attracted to the anode
- Creates bulk movement of solute in response to the electrical field and helps move ions into the tissue
- Human skin contains net negative charge, direction of electroosmotic flow is from the anode to the cathode
--> assists in delivery of positive medications
--> hinders delivery of negative medications
54
Two important aspects of application of Iontophoresis
1. know the polarity of the ion or drug to be used
2. Have a good conductivity so there is not a chemical burn under the electrode
55
Selecting an Ion: Inflammation
1. Drug= dexamethasone
2. Polarity= Negative
3. Effect= anti-inflammatory
56
Selecting an Ion: Calcific tendonitis, myositis ossification
1. Drug= Acetic acid
2. Polarity= negative
3. effect= increases solubility of calcium deposits
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Selecting an Ion: Adhesive capsulitis/ soft tissue adhesion
1. Drug= iodine
2. Polarity = negative
3. effect= sclerolytic effect
58
Selecting an Ion: Soft tissue and Inflammation
1. Drug= Lidocaine
2. Polarity= positive
3. Effect = local anesthetic effect
59
Selecting an Ion: Muscle and joint pain
1. Drug= salicylates
2. Polarity= negative
3. effect=analgesic and anti-inflammatory
60
Selecting an Ion: Local substance or chronic edema
1. Hyaluronidase
2. polarity positive
3. effect= dispersion of local edema
61
Selecting an Ion: Skeletal Muscle Spasms
1. Calcium Chloride
2. polarity positive
3. effect= decreased excitability of peripheral nerves and skeletal muscle
62
Selecting an Ion: skeletal muscle spasms /myositis
1. Magnesium Sulfate
2. polarity positive
3. effect= muscle relaxant
63
Selecting an Ion: Skin ulcers
1. zinc oxide
2. polarity positive
3. General antiseptic; increase tissue healing
64
Selecting an Ion: Hyperhidrosis
1. Tap water
2. polarity alternating
3. effect= dec sweating palms, feet or axillae
65
Cathode conductive surface area should be
>anode up to 2x the area
66
Where should the active/treatment electrode go directly over?
directly over the treatment area
- Inactive electrode distant from the treatment electrode
67
T/F when electrodes are spaced further apart they will increase the depth of the current and drug penetration
True
68
Iontophoresis Dosage equation
dosage (mA min)= current (mA) x duration (min)
typical dosage ranges from 20-80 mA min
69
