Non-Systems: Therapeutic Modalities: Ultrasound: Physiologic Effects Flashcards
1
Q
Thermal
A
- Produced by continuous sound energy
2
Q
Thermal: 1MHz ERA
A
- 1.5 to 2.0 W/cm^2
3
Q
Thermal: 3MHz ERA
A
- 0.5 to 1 W/cm^2
4
Q
Thermal: Deep tissue
A
- A significant rise in tissue temperature can take up to 10 minutes or more for deeper tissues
5
Q
Thermal: “Hot Spot”
A
- Insufficient coupling agent may produce discomfort caused by. hot spot which is the uneven distribution of heat
6
Q
Non-thermal
A
- Produced by pulsed sound energy
7
Q
Non-thermal: Cavitation
A
- Alternating compression and expansion of small gas bubbles in the tissue fluids caused by mechanical pressure waves
8
Q
Non-thermal: Cavitation: Stable
A
- Gas bubbles resonate without tissue damage
9
Q
Non-thermal: Cavitation: Unstable
A
- Severe collapse of gas bubbles during compression phase ultrasound can result in local tissue destruction due to high temperatures
10
Q
Acoustic Streaming
A
- Movement of fluids along the boundaries of cell membranes resulting from mechanical pressure wave
