Diathermy Lecture Flashcards
1
Q
how does diathermy, “heat through”?
A
local heating by electromagnetic waves
2
Q
what are the 2 frequency types that may be used in diathermy?
A
microwave or radio
3
Q
what is the most widely used form of diathermy?
A
short wave diathermy (SWD)
4
Q
what is the MHz of SWD?
A
27.12 MHz
5
Q
what are the two types of SWD?
A
capacitive and inductive
6
Q
which type of SWD uses electrical field?
A
capacitive SWD
7
Q
which type of SWD uses magnetic field?
A
inductive SWD
8
Q
how does capacitive SWD work?
A
the body part is placed bw the capacitive electrodes of the SWD device and the electrodes cause an oscillating electric current to flow through the body tissues
resistance to this current flow results in tissue heating
9
Q
does capacitive SWD concentrate the electric field in superficial or deep tissues?
A
superficial skin and fat
10
Q
what heats up quicker, skin/fat or muscle?
A
skin/fat, which can lead to greater burns
11
Q
capacitive SWD is best for treating what tissues?
A
superficial areas low in subQ fat
12
Q
t/f: touching exposed electrode plates in capacitive SWD can lead to burns, so it has glass or plastic guards surrounding it
A
true
13
Q
t/f: with capacitive SWD, the closer the metal plates to the skin, the greater the heat sensation
A
true
14
Q
what are the plate arrangement options in capacitive SWD?
A
contraplanar and coplanar
15
Q
what is the contraplanar arrangement of plates in capacitive SWD?
A
plates are placed on each side of the body part
16
Q
t/f: in contraplanar arrangement of capacitive SWD, the body part becomes a biological capacitor
A
true
17
Q
contraplanar arrangement of plates in capacitive SWD is best used for treating what body parts?
A
extremities
18
Q
what is the coplanar plate arrangement in capacitive SWD?
A
the plates are positioned parallel to the same body surface
19
Q
the coplanar arrangement in capacitive SWD is best used for what body part?
A
the back, neck, and pelvis
20
Q
t/f: capacitive plates shouldn’t be placed over areas of thick subQ fat
A
true
21
Q
what is the more common type of SWD we see?
A
inductive SWD
22
Q
what type of applicator consists of a coil through which alternating current flows and creates an oscillating magnetic field perpendicular to the coil that induces “eddy” currents in the body tissues?
A
inductive applicator in inductive SWD
23
Q
in inductive SWD, the greatest density of eddy current activity and heating occurs where?
A
in low impedence (high conductivity) tissues such as muscles, synovial fluid, and blood
24
Q
what body tissues are low impedence?
A
ms, synovial fluid, and blood
25
does inductive SWD heat more superficial or deep tissues?
deeper tissues like ms
26
what is the depth of penetration of inductive SWD?
~2" (5cm)
27
is there more perception of heat with inductive or capacitive SWD?
capacitive SWD
28
what is the drum applicator in inductive SWD?
a coil shaped cable contained in rigid plastic insulator housing
29
what are the 3 types of drum applicators in inductive SWD?
monode
diplode
induction sleeve
30
what is a monode applicator in inductive SWD?
a drum used to treat a single body surface
31
which type of inductive applicator is the clinical norm?
the monode
32
what is a diplode applicator in inductive SWD?
a hinged drum that allows one or more body surfaces to be treated
33
are more or less towels needed with a diplode inductive SWD?
more
34
is the drum coil closer or farther away from the tx surface with the diplode applicator in inductive SWD?
closer to the tx surface
35
what is an induction sleeve applicator in inductive SWD?
a sleeve designed to fit around a body part like a Game Ready
36
the heating ability of an induction sleeve is limited to ____ tissue temp increases
moderate
37
t/f: on older inductive SWD units with external cables, don't allow the cables to come in contact with the pt, metal, or synthetic materials
true
38
most pulsed SWD (PSWD) uses what SWD?
inductive method
39
what type of SWD uses a burst of EM waves created by interrupting flow of continuous waves
PSWD
40
what is the burst/pulse duration range for PSWD?
40-400usec
41
what is the burst frequency of PSWD?
1-1000pps
42
what is the peak power of PSWD?
100-1000W
43
heating effect on tissue with PSWD depends on what?
the avg power
44
what is the calculation for avg power in PSWD?
peak power (W) x pulse duration (s) x pulse frequency
45
t/f: PSWD can have thermal and non thermal effects
true
46
is PSWD able to vigorously heat deep tissues?
yup!
47
t/f: both continuous and pulsed diathermy can heat tissue if the signals avg intensity is sufficiently high
true
48
an avg power of signal >___ can increase tissue temp
38W
49
an article found that a PSWD device with avg power of ____W can increase ms tissue temp at a depth of ____cm up to ____-deg F to heat the tissue and change pliability
48W
3cm
8.3 deg F (4.6 deg C)
50
how is continuous diathermy delivered?
with no interruption of the electromagnetic waves from the device
51
how is pulsed diathermy delivered?
with regular, brief interruptions of EM waves from the device
52
what is the MHz of long wave diathermy (LWD)?
0.3-1.0 MHz
53
what is the MHz of microwave diathermy (MWD)?
2,450 MHz
54
what type of diathermy has a magnetron that generates AC at a high power level that is transmitted to an antenna housed in an emitter (drum or applicator) that directs the EM field to the body part?
MWD
55
t/f: with MWD, the emitter must be at a right angle to the body part to limit reflection of waves
true
56
t/f: in MWD some emitter are placed in contact with the skin while others are placed a short distance from the skin
true
57
do the thermal effects of MWD penetrate as deep as SWD?
no
58
do waves in MWD concentrate energy in more superficial or deeper tissues?
more superficial tissues
59
is MWD better than SWD?
no
60
which has a higher frequency SWD or MWD?
MWD
61
which type of diathermy allows for a more focused area of tx?
MWD
62
is MWD changing the molecular structures in the tx tissues?
nope
63
why isn't MWD used much in the US?
by SWD has a greater depth of heating and a more predictable heat distribution pattern
64
t/f: evidence shows no dif in outcomes of thermal MWD, non-thermal MWD, and placebo groups
true
65
what type of waves are used in pulsed electromagnetic fields (PEMF)?
radio frequency waves
66
is PEMF high or low intensity?
low intensity
67
is PEMF thermal or non thermal?
non thermal (similar to microcurrent)
68
t/f: with PEMF, the coil is placed on the skin
true
69
what is the avg power of PEMF?
1 W or less
70
evidence supports PEMF for what things?
promoting superficial wounds and bone healing
71
how does PEMF promote superficial wounds and bone healing?
by facilitation of cellular metabolism and ionic fluctuation
72
t/f: PEMF significantly decreases pain of knee OA and SAI
false
73
are the changes very obvious with PEMF?
no, they are subtle
74
t/f: energy absorbed by tissues in diathermy may inc temp depending on the intensity of the waves and whether the waves re continuous or pulsed
true
75
do radio/microwave frequency waves effect more superficial or deeper tissues of the body?
deeper tissues
76
is there a lot of accumulation of energy at the tissue/bone interface with radio/microwave frequencies?
no
77
who introduced diathermy? when?
Dr. Nagelschmidt in 1907
78
what were the problems with diathermy units in the 60s-80s?
tedious setup
poor shielding
elevated radio frequencies interfered with telemetry and other medical devices
overheating of subQ fat
research a ND education was limited
79
are diathermy frequencies capable of depolarizing motor nerves or eliciting contractile repsonses from innervated/denervated ms?
no
80
EM waves in the radio frequency range are _____ radiation
nonionizing
81
what does it mean that radiofrequency is nonionizing radiation?
it is insufficient yenergy concentration to dislodge electrons form atoms and induce mutations or uncoupling of DNA
82
what are the physiologic effects of diathermy?
micro circulation
thermal effects (inc tissue temp)
non thermal effects
83
what are the thermal effects of diathermy?
increased extensibility of collagen fibers in tendons and jt capsules
decreased jt stiffness
reduced ms spasm, relaxation
diminished pain perception
increased metabolism
increased blood flow
vasodilation
increased membrane filtration and diffusion
changes in some enzyme rxns
84
what are the non thermal effects of diathermy?
reduction of intracellular edema
triggering of collagen synthesis
increased microvascular perfusion
accelerate soft tissue healing
activation of fibroblast growth factors
increased macrophage activity
decrease pain
PSWD pain relief esp with vasculitis, connective tissue disorders; reduce post-op pain
85
what are the benefits of microcirculation with SWD?
inc oxygenation
facilitate blood flow
promote natural healing effects (removal of dead cells, inc nutrients to the region)
86
what 3 things result in thermal effects in diathermy?
high frequency oscillating EM field causes back and forth motions of ions resulting in collisions that produce heat through increased internal kinetic energy
rotation of diploes (water molecules) results in increased random motion of adjacent molecules and produces heat
distortion of atoms and molecules that aren’t charged results in increased random motion of adjacent molecules, which may cause some heat
87
what temp Inc is necessary to cause change in tissue extensibility?
4 deg C
88
should a 4 deg C tissue temp inc be used in elderly pts? why or why not?
no bc the yoften have dec sensation and also don't whisk away heat as quickly which can lead to burns
89
what is the tx time for a 4 deg C temp inc with diathermy?
20 min
90
what is the tx time for a 2-3 deg C temp inc with diathermy?
20 min
91
what is the tx time for a 1 deg C temp inc with diathermy?
20 min
92
what is the pulse width of diathermy for a 4 deg C temp inc?
400usec
93
what is the pulse width of diathermy for a 2-3 deg C temp inc?
200usec
94
what is the pulse width of diathermy for a 1 deg C temp inc?
100usec
95
what is the pulse rate of diathermy for a 4 deg C temp inc?
800pps
96
what is the pulse rate of diathermy for a 2-3 deg C temp inc?
800pps
97
what is the pulse rate of diathermy for a 1 deg C temp inc?
800pps
98
what is the avg power of diathermy to inc temp 4 deg C?
48W
99
what is the avg power of diathermy to inc temp 2-3 deg C?
24W
100
what is the avg power of diathermy to inc temp 1 deg C?
12W
101
what types of SWD are more effective at elevating deep tissue temp (5cm)?
inductive SWD and PSWD
102
does capacitive SWD work as well as inductive SWD and PSWD at elevating deep tissue temp?
nope
103
inductive SWD is effective at heating tissues with ____ conductivity and _____ electrolyte content, particularly those with ____ perfused blood
high, high, well
104
t/f: inductive SWD and PSWD causes less heating of fat, bone, and collagen tissues compared to capacitive diathermy
true
105
t/f: there is evidence of heating a ms bw 2-5.2 deg C for inc extensibility of tissues
true
106
articles have found that SWD heat develops after about how many minutes?
range from 10-20 min
107
articles have found that SWD heat plateaued around how many minutes?
range from 10-20 min
108
a study by Draper found that tissue heat declines slowly at a rate of...
1 deg C per 5 min
109
a study by Sousa found that tissue retained heat until ___ min post tx
40
110
what is the therapeutic window with diathermy?
5-10 min
111
a study by Beninca found that what arrangement had the slowest temp decay?
coplanar
112
a study by Beninca found that ___ dose application of continuous capacitive SWD had the lowest temp change
low
113
a study by Beninca found that what technique of PWSD increased ms temp the most?
inductive
114
what PSWD had the slowest temp decay?
inductive PSWD
115
the lowest temp change was found in what application of SWD?
inductive sleeve
116
the amount of energy delivered with diathermy depends on what factors?
continuous or pulsed
proximity of electrode, drum, emitter to pt’s skin
power output (W)
duration of tx
117
why is a towel often used with diathermy?
to create space and absorb any moisture for comfort
118
what is the tx time for subthermal SWD?
30 min
119
what is the pulse width of subthermal SWD?
65usec
120
what is the pulse rate of subthermal SWD?
400pps
121
what is the avg power of subthermal SWD?
3-9W
122
subthermal tx should not exceed ____ W of avg power
5
123
t/f: we want to get as close to the skin as possible with subthermal SWD
true
124
what is dosage in diathermy?
the amt of energy delivered to the body that's converted into heat
125
are we able to measure dosage of diathermy directly?
no, we need to monitor the pt's report of heating sensation on their skin and deeper tissues as a dose guide
126
for non thermal effects, avg power should be set <___W
38
127
what are the indications for SWD, PSWD, and MWD?
greater depth of heating than superficial modalities
heat larger area than US
128
t/f: diathermy is the best choice for heating large jts like the knee, hip, and shoulder
true
129
what are the target tissues of diathermy?
ms, ligs, blood, wounds, cartilage (more MSK stuff)
130
what are the target tissues of US?
nerves, GTO, tendon, ms, and wounds
131
is there pt contact with diathermy?
no, there's a very small separation
132
is there pt contact with US?
yes with a medium used
133
what conditions does the research show (+) effects of diathermy for?
knee OA
chronic LBP
chronic pelvic inflammatory disease
jt ROM
HS flexibility
elbow/shoulder/ACL surgery
RA
acute ms injury
ecchymosis and hematoma (subthermal)
ligament pain
134
what conditions does the evidence show that diathermy is ineffective for?
tight HS
chronic LBP
chronic neck pain
SAI
knee OA
neck disorders
jt ROM
(but these are all literally listed under effective too, don't ask bc I don't know:()
135
what are some considerations we should take into account when using diathermy?
presence of metal on pt and in tx area
presence of imbedded metal
active implanted medical devices
136
t/f: the longer the metal implants, the greater the shunting effect of heat
true
137
t/f: a pt should remove all jewelry and piercings with diathermy usage and any clothes with metal
true
138
t/f: application of diathermy over looped wires is contraindicated
true
139
t/f: small pieces of imbedded metal is unlikely to cause tissue burning with diathermy
true
140
t/f: diathermy is safe for rods, plates, and screws
true (but why tho...)
141
diathermy over what active implanted medical devices should be avoided?
cardiac pacemakers
implantable cardioverter defibrillators
cochlear implants
implantable neurostimulators
implantable infusion pumps
142
pts with active implanted medical devices should stay about ___ ft away (can go through walls)
20
143
are active implanted medical devices contraindicated in thermal or subthermal diathermy?
both
144
with continuous SWD/MWD, are there studies on using it over metal implants?
no, so it is a contraindication
145
t/f: diathermy should be avoided over a copper IUD
true, it can cause pain
146
if a clinician is pregnant, should they be near diathermy?
nope
147
t/f: it is normal to have some redness after diathermy, but it should only last a few min
true
148
what are the precautions for diathermy?
cardiac pacemakers
implantable cardioverter defibrillators
cochlear implants
implantable neurostimulators
implantable infusion pumps
149
what are the contraindications for diathermy?
any metallic object on the pt or within the electromagnetic field
any metals imbedded in the body
metal loops imbedded in the body
cancerous tissues
hemorrhage or increased tendency of hemorrhage
cardiac pacemakers, implanted stimulators, including any device w/lead wires attached or unattached
acute injury or inflammation
pregnancy
jts or organs containing high levels of fluid, including the eyes or testes
synthetic materials such as clothing, pillows, and bed coverings
head, face, or TMJ for pts wearing contact lenses
unconscious pts or pts who’re mentally confused
over moist clothes, dressings, or accumulations pf perspiration on the skin
loss of sensation in area of the body to be treated
pts with severe circulatory impairment (peripheral vascular disease, etc)
150
how far from the pts skin should the capacitive or microwave drum be placed?
1-3 inches away
