Ultrasound
Ultrasound
Physical effects of ultrasound:
1- Thermal effects
2- Non-thermal effects
3- Effect of US in tissue repair
First: thermal effect
@ It is due to generation of heat within the tissue due to adsorption of US.
@ Tissue with high amount of protein absorbs US more than other tissues.
@ Generation of heat within the tissue will decrease pain, joint stiffness & increase blood flow.
@ Thermal effect achieved if the temperature of the tissue is raised to 40°c - 45°c for at least 5 minutes, so the treatment time should not be less than 5 minutes.
@ It is important to know:
* Type of injury.
* Nature of the tissue of injured area.
* Which freq to use?!!
* The blood flow in injured area.
* Never apply US over metal prosthesis (mode conversion ( increase temperature ( pain.
Second: non-thermal effect Non-thermal effect cause@
* Stimulation of tissue repair.
* Increase blood flow in chronically ischemic tissue.
* Protein synthesis.
* Bone repair.
@ This is can be achieved by:
1- Cavitations ( it is formation of very small bubbles in gas containing fluid which leads to changes in cell permeability to various ions as calcium "by low pressure amplitudes".
2- Acoustic streaming ( it is the unidirectional movement of the fluid in the US field which leads to:
* Stimulation of cell activities.
* Stimulation of cell permeability & 2nd messenger activities ( acceleration of tissue repair because of:
1- Increase protein synthesis.
2- Increase secretion from mast cell.
3- Changes in fibroblast mobility.
4- Increase the uptake of 2nd messenger calcium.
5- Increase production of growth factors by macrophages.
3- Standing waves ( it is formed by interact of oncoming waves & reflected waves of US. This reflection due to the hits of US waves at the interface between 2 different tissues (e.g. bone & muscle).
There are 3 points of this wave, maximum& minimum antinodes "where gas bubbles collected" & fixed nodes "where cells
Physical effects of ultrasound:
1- Thermal effects
2- Non-thermal effects
3- Effect of US in tissue repair
First: thermal effect
@ It is due to generation of heat within the tissue due to adsorption of US.
@ Tissue with high amount of protein absorbs US more than other tissues.
@ Generation of heat within the tissue will decrease pain, joint stiffness & increase blood flow.
@ Thermal effect achieved if the temperature of the tissue is raised to 40°c - 45°c for at least 5 minutes, so the treatment time should not be less than 5 minutes.
@ It is important to know:
* Type of injury.
* Nature of the tissue of injured area.
* Which freq to use?!!
* The blood flow in injured area.
* Never apply US over metal prosthesis (mode conversion ( increase temperature ( pain.
Second: non-thermal effect Non-thermal effect cause@
* Stimulation of tissue repair.
* Increase blood flow in chronically ischemic tissue.
* Protein synthesis.
* Bone repair.
@ This is can be achieved by:
1- Cavitations ( it is formation of very small bubbles in gas containing fluid which leads to changes in cell permeability to various ions as calcium "by low pressure amplitudes".
2- Acoustic streaming ( it is the unidirectional movement of the fluid in the US field which leads to:
* Stimulation of cell activities.
* Stimulation of cell permeability & 2nd messenger activities ( acceleration of tissue repair because of:
1- Increase protein synthesis.
2- Increase secretion from mast cell.
3- Changes in fibroblast mobility.
4- Increase the uptake of 2nd messenger calcium.
5- Increase production of growth factors by macrophages.
3- Standing waves ( it is formed by interact of oncoming waves & reflected waves of US. This reflection due to the hits of US waves at the interface between 2 different tissues (e.g. bone & muscle).
There are 3 points of this wave, maximum& minimum antinodes "where gas bubbles collected" & fixed nodes "where cells