Diathermy Flashcards
1
Q
What does diathermy mean
A
Through Heat
2
Q
What is diathermy
A
High frequency modality emitting electromagnetic energy
3
Q
What are the type of diathermy (3)
A
- Shortwave
- Microwave
- Longwave
4
Q
What are the types of shortwave diathermy (2)
A
- Continuous
2. Pulsed
5
Q
Is longwave diathermy still used today
A
No
6
Q
What is the most common frequency and wavelength of longwave diathermy
A
1 MHz, 300m
7
Q
What is the most common frequency and wavelength of shortwave diathermy
A
27.12 MHz, 11m
8
Q
What is the most common wave length of microwave diathermy
A
2450 MHz, 0.12m
9
Q
Who regulates shortwave diathermy
A
FCC
10
Q
What spectrum is shortwave diathermy in
A
Shortwave radio spectrum
11
Q
What does shortwave diathermy mainly form
A
Magnetic fields in tissue
12
Q
What does microwave diathermy mainly form
A
Electric fields in tissue
13
Q
Why is microwave diathermy rarely used anymore (6)
A
- Metal in vicinity
- Skin burning
- Overheating of superficial tissue
- Increased reflection at tissue interfaces
- Loss of energy to surrounding environment
- Hot spots
14
Q
Does shortwave diathermy use high or low frequency EMW to heat tissue
A
High frequency
15
Q
What is shortwave diathermy in very basic terms
A
A radio transmitter
16
Q
What are the available frequencies and wavelengths for shortwave diathermy (3)
A
- 27.12 MHz, 11 m
- 13.56 MHz, 22 m
- 40.68 MHz, 7.5 m
17
Q
Of the 3 available frequencies and wavelengths which one is rarely used
A
40.68 MHz, 7.5 m
18
Q
The patient acts as what during shortwave diathermy
A
Radio receiver
19
Q
True or False:
During shortwave diathermy the patient is “tuned in” as part of the circuit allowing for transfer of energy to the patient
A
True
20
Q
When is current flow the greatest and example
A
In tissues with the least resistance like fat
21
Q
When is the current absorption greatest and examples
A
In tissues with low impedance like muscle or blood
22
Q
What was continuous shortwave diathermy used to treat in the 1930s
A
Infection
23
Q
Is continuous shortwave diathermy used to treat infection today
A
It is used with caution due to rapid and vigorous heating of tissue
24
Q
What is pulsed shortwave diathermy (PSWD) used for
A
Creating thermal and non-thermal effects
25
What does a wider pulse width mean
There is more energy generated to the tissue
26
What is pulse width measured in and the range
usec from 20-400
27
What happens when the pulse rate is greater
The amount of energy produce and transmitted into the tissue is greater
28
What is pulse rate measured in
Hz
29
What are the temperature sensations for PSWD (4)
1. Non thermal
2. Mild warmth
3. Moderate warmth
4. Vigorous heating
30
What are indications for non thermal PSWD (4)
Acute trauma, noticeable inflammation, edema reduction, and cell repolarization and repair
31
What are the indications for mild warmth PSWD (1)
Subactue inflammation
32
What are the indications for moderate warmth PSWD (3)
Pain reduction, muscle spasm, and chronic inflammation
33
What are the indications for vigorous heating PSWD (1)
Stretching collagen rich tissues
34
What are the pulse width and rate for non thermal PSWD
PW: 65 usec
PR: 100-200 pps
35
What are the pulse width and rate and average watts for mild heating PSWD
PW: 100 or 200 usec
PR: 400 or 800 pps
Watts: 12
36
What are the pulse width and rate and average watts for moderate heating PSWD
PW: 200 or 400 usec
PR: 400 or 800 pps
Watts: 24
37
What are the pulse width and rate and average watts for vigorous heating PSWD
PW: 400 usec
PR: 800 pps
Watts: 48
38
What is ionic oscillation
Charged particles oscillate producing kinetic energy
39
What charged particles are used in ionic oscillation (3)
Na+, K+, and Cl-
40
What is dipole rotation
Dipolar or water molecules (H+ and O-) rotate and produce kinetic energy
41
What are the physiologic effects of thermal diathermy (8)
1. Increase local metabolism
2. Local vasodilation
3. Muscle relaxation
4. Sedation of sensory nerve endings
5. Increased local perspiration
6. Increased collagen extensibility
7. Increased nerve growth and repair
8. Increased body temp, pulse rate, and decreased BP
42
What are the physiologic effects of non thermal diathermy (7)
1. Repolarization of damaged cells
2. Regularization of cell growth
3. Reestablishment of the Na+ pump
4. Increased microvascular perfusion
5. Improved cell function
6. Increased white cells in wound
7. Altered cell membrane function and cellular activity
43
What are the clinical indications for the use of PSWD (5)
1. Control of pain and edema
2. Pain control
3. Wound healing
4. Nerve healing
5. Bone healing
44
What are the indications for the use of diarthermy (4)
1. Impairments associated with sub acute and chronic conditions
2. Tissue contractures/adhesions
3. Joint stiffness
4. Stimulation of perspiration to improve electrical conductivity prior to E-Stim
45
What are the contraindications for diathermy (11)
1. Acute injuries
2. Patients who tend to hemorrhage
3. Malignancy
4. Fever
5. Over eyes
6. Over ischemic tissue
7. Cardiac disease
8. Pregnancy
9. Over epiphyseal plates in adolescents
10. Metal in treatment area
11. Pacemaker
46
What are the advantages to diathermy (5)
1. Tissue can't tolerate weight of a hot pack
2. Can reach deeper tissues
3. Can cause mild rise in temperature of deep tissue
4. Can treat a larger area
5. Not reflected by bone
47
What are the disadvantages to diathermy (2)
1. Costly equipment
| 2. Tissue being treated may not be visible
48
What are the types of electrodes used for diarthermy (2)
1. Capacitor electrodes
| 2. Induction electrodes
49
What is a capacitor electrode
A positively charged electrode that repels positive ions and attracts negative ions
50
Do capacitor electrodes create a strong magnetic of electric field
Stronger electric field
51
True or False:
| The center of a capacitor electrode has a higher current density
True
52
True or False:
| The patient is placed between two electrodes or plates and becomes part of the electric circuit
True
53
When using a capacitor electrode what tissues develop the greatest heat
Tissues that offer the greatest resistance to current flow
54
Which tissue offers the greatest resistance to flow
Fat
55
What are the 2 types of capacitor electrodes
1. Air spaced plates
| 2. Pad electrodes
56
Are air spaced plates seldom used or used quite frequently
Seldom used
57
How big are the 2 metal plates for air spaced plates
7.5-17.5 cm in diameter
58
What are the metal plates surrounded by for air spaced plates
Glass or plastic guard
59
What types of tissues are air spaced plates good for
Areas low in subcutaneous fat such as hands feet wrists ankles spine and ribs
60
What must be done in order to properly use pad electrodes
1. Must have uniform contact with the skin
2. Several layers of towels between pads and skin
3. Pads should be apart at least as far as they are wide
4. Tissue being treated should be centered in the electrode
61
What does increasing the distance between pads do for pad electrodes
Increases the depth of penetration
62
What do induction electrodes create stronger magnetic fields or electric fields
Stronger magnetic fields
63
True or False:
| Induction electrodes induce localized secondary eddy currents
True
64
Is the patient inside or outside of the magnetic field in induction electrodes
Inside
65
What tissues cause the greatest current flow when using induction electrodes
Tissues with the lowest resistance
66
True or False:
| When using induction electrodes tissues high in electrolyte content (muscle and blood) increase in temperature
True
67
What are the types of induction electrodes (2)
1. Cable
| 2. Drum
68
What is a cable induction electrode
Coil that is wound flat
69
How big should the diameter of the center coil be for cable induction electrodes
Bigger than 6 cm
70
How many cms of toweling should be between the coil and skin with cable induction electrodes
1 cm
71
True or False:
| Spacers are used to keep the coils 5-10 cms between turns
True
72
What is a drum induction electrode
One or more monoplanar coils fixed inside a housing unit
73
What is the depth of penetration of a drum induction electrode if the drum is no more than 1-2 cm away from the skin
2-3 cm
74
True or False:
| A towel does not need to be place between the skin and the drum because the moisture does not create hot spots
False:
75
True or False:
| The housing should be in contact with the toweling for the best penetration
True
76
What is dose I
No perception of heat
77
What is dose II
Mild perception of heat
78
What is dose III
Comfortable perception of heat
79
What is dose IV
Maximum tolerable perception of heat
80
What are the general parameters for diathermy (4)
1. Power
2. Frequency
3. Mode
4. Duration
81
What can the power be up to in continuous mode
800 watts
82
What is power equal to in pulsed mode
Mean power = peak power*pulse duration*frequency
83
What are the parameters for shortwave diathermy (3)
1. Pulse duration is 20-400 usec
2. Pulse intensity is 1000 W/pulse
3. Pulse repetition is 1-7000 Hz
84
What does the off period allow for during PSWD
Heat to dissipate
85
True or False:
The decay of heating in the target tissue is slower for PSWD than it is for US allowing for more time for manual techniques
True
86
Does fat have the highest resistance to flow and the lowest resistance to flow
Highest: Electric fields
Lowest: Magnetic fields
