Diathermy Flashcards
how is diathermy reflection of waves different than that of ultrasound?
Minimal reflection of waves at tissue interfaces and on bone, so there is little accumulation of energy at these interfaces as would occur with ultrasound
Most common diathermy devices use what type of wave length?
delivers 27.17mHZ frequency waves from the short radio wave section. referred to as shortwave diathermy (SWD)
what is special about a machine called microwave diathermy (MWD)?
Devices that deliver electromagnetic waves from the microwave range of the electromagnetic spectrum are known asmicrowave diathermy(MWD).
Can diathermy only be used as a continuous frequency (T or F)
False
diathermy can be used continuously, regular pulse, or burst of radio frequency energy.
Devices that deliver this type of low radio frequency wave are called? is this wave thermal or non thermal
Devices that deliver radiofrequency waves to the patient at a very low intensity are known aspulsed electromagnetic fields(PEMF) orpulsed radiofrequency energy.
The intensity of the waves delivered by these devices is too low to create heat in body tissues (nonthermal)
How does short wave diathermy work?
Either continuously (no interruption of electromagnetic waves coming from the device) or by pulse (regular brief interruption of waves from the device).
Two types of SWD: electric field (capacitive) method and magnetic field (inductive) method.
By placing a body part between the capacitive electrodes of the SWD device, the body part serves as a dielectric. The capacitive electrodes cause an oscillating electric current to flow through the body tissues between the electrodes. Resistance to this current flow in the tissues results in tissue heating.
The specific absorption rate of radiofrequency waves for capacitive SWD is higher for fat tissue than for muscle because fat tissue has a greater resistance to current flow than muscle.108The result is greater heating of fat tissue and less heating of muscle.
In capacitive SWD what has the higher absorption rate muscle or fat?
The specific absorption rate of radiofrequency waves for capacitive SWD is higher for fat tissue than for muscle because fat tissue has a greater resistance to current flow than muscle. The result is greater heating of fat tissue and less heating of muscle.
How does capacitive SWD work?
Capacitive electrodes cause an oscillating electric current to flow through the body tissues between the electrodes.
Resistance to this current flow in the tissues results in tissue heating.
Inductive SWD is beneficial in heating what type of tissue?
Inductive (magnetic field) diathermy will more effectively heat muscle than capacitive diathermy with less heating of skin and subcutaneous tissue.
what is the typical dosage for diathermy treatments?
15-30 minutes
what repose does a dose 1 have?
non thermal
what repose dose a does 2 have?
mild heat sensation
what does response 3 have?
moderate heat sensation
what does a does three response look like?
vigorous healing
what is the tissue temperature rise for dose one of diathermy?
none
what is the tissue temperature rise for dose two of diathermy?
1.8 F 1 C
what is the tissue temperature rise for dose three of diathermy?
3.6 F. 1C
what is the tissue temperature rise for dose four of diathermy?
7.2 F. 2 C
what is the average watts for dose one of diathermy?
N/A
what is the average watts for dose two of diathermy?
12W
what is the average watts for dose three of diathermy?
24W
what is the average watts for dose four of diathermy?
48 W
what are the suggested target tissues for dose one of diathermy?
acute injuries (sprains, strains, etc.) edema reduction, cell repair
what are the suggested target tissues for dose two of diathermy?
subacute injuries and inflammation
what are the suggested target tissues for dose three of diathermy?
pain, muscle spasms, chronic inflammation
what are the suggested target tissues for dose four of diathermy?
increase blood flow, healing of collagen tissues for stretching of soft tissues
what are the contraindications and indications for diathermy?
Similar to thermal/ultrasound
Diathermy provides a greater depth of heating than superficial thermal modalities and it can heat a larger area (greater amount of tissue) than ultrasound.
These advantages make diathermy the best choice for heating large joints, such as the knee or shoulder, or large muscles, such as the hamstrings.
Also the risk of soft tissue burns is less with diathermy than with conductive heating modalities such as hot packs
when is diathermy indicated the most?
Diathermy is indicated whenever heating of deep tissues (up to 3 to 5 cm) is desired.
