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Flashcards in Diathermy Deck (20)
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1
Q

What type of modality is Diathermy?

A

Heat

2
Q

What are the two types of generators of Diathermy?

A

Shortwave (most common) and microwave

3
Q

What is diathermy?

A

• High frequency electromagnetic energy
– Generate heat in body tissues (deep heating)
– Non-thermal effects (questionable)

4
Q

T/F: Electromagnetic energy travels at the speed of sound?

A

FALSE; it travels at the speed of LIGHT! (300,000,000 m/s)

5
Q

What is the most common frequency of shortwave diathermy?

A

27.12 MHZ, 11 meter λ

6
Q

Does microwave or shortwave diathermy penetrate deeper?

A

Shortwave

7
Q

Is shortwave or microwave diathermy safer?

A

Shortwave

8
Q

What type of electrode is used to produce an electrical field?

A

Capacitor electrode

9
Q

What type of electrode is used to produce a magnetic field?

A

Induction electrode

10
Q

Why should the capacitive technique be used on Thin patients?

A

It may heat subcutaneous fat more than muscle. Use for patients/areas with low subQ fat
– Knee, foot, hand, shoulder

11
Q

When should you use the inductive technique?

A
Greatest absorption in high electrolyte,
high dipole tissue
– Deeper
– Muscle, tendon, joint
• Use for patients with more subQ fat /
obese patients
12
Q

What law is Dose vs response?

A

Arndt-Schultz Law

13
Q

What law is Absorption vs therapeutic effect?

A

Grotthuss-Draper Law

14
Q

Inverse square

A
– Dose vs divergence
– E.g. Change from 10 cm
to 20 cm = 2x distance
– Inverse of 2 = ½
– Square of ½ is ¼
– Therefore ¼ as much
heat with 2x the
perpendicular distance
15
Q

Cosine Law

A
Lambert’s
Cosine law
– Angle of
application
– Reduced
energy if angle
is increased.
16
Q

Physiologic responses to diathermy:

A
• Continuous Short Wave Diathermy
– CSWD
– Less common
• Pulsed Short Wave Diathermy
– PSWD
– More common
– Heat vs no heat
• Heat
– Pain relief, wound management, joint
contracture
17
Q

What are the indications to use diathermy?

A
• Research
– Osteoarthritis
– Neck/back pain
– Ankle pain
– Dermal wounds
• Other musculoskeletal injuries /
musculoskeletal pain
18
Q

What are the contraindications of diathermy?

A
  • Loss of sensation
  • Electronic implants (even if device is gone but leads remain)
  • Surgically implanted metal (clips, rods, pins, etc)
  • Metal in contact with the skin (jewelry, tmt table, etc)
  • Over cancerous areas
  • Pregnant patients – abdomen, pelvis, and low back
  • Hemorrhagic areas
  • Ischemic areas
  • Testes
  • Eyes
  • Open growth plates in children
19
Q

What are the risks associated with Diathermy?

A
• Pregnant operator should not be exposed
daily
– Remain 3 feet from functioning SWD device
• Copper IUDs
• Other patients near the device
– 10 foot distance
• Other EPA devices – 10 foot distance
• Mentally confused patients
20
Q

How do you apply diathermy?

A
  • Test cold/warm sensation first
  • Remove jewelry
  • 2-3 cm layer of towels for spacing
  • Advise patient to remain still