Cavitation refers to the formation and behavior of tiny gas or vapor-filled bubbles (cavities) within tissues that are produced by ultrasound waves colliding. These bubbles expand and collapse rapidly, creating mechanical forces that have various effects, including:
The rapid expansion and collapse of bubbles creates microstreaming, which is the movement of fluid near the bubbles. This microstreaming helps to enhance the transport of nutrients and remove waste products from cells, promoting tissue healing.
Altered Cellular Membrane Permeability
Cavitation-induced mechanical forces enhance the permeability of cellular membranes. This facilitates the uptake of therapeutic substances into cells, improving the effectiveness of drug delivery in certain situations.
Acoustic streaming is the steady flow of fluid induced by the passage of ultrasound waves through a liquid medium. This streaming influences the movement of cells and substances within tissues, facilitating tissue repair and promoting the removal of metabolic waste products.
Therapeutic ultrasound produces mechanical vibrations in tissue, which we apply for therapeutic purposes. These mechanical effects include the relaxation of muscle fibers leading to improvements in muscle spasms, breaking down fibrous tissue, such as scar tissue or adhesions, stimulating microcirculation of blood in tissues, and potentially improving tissue oxygenation and nutrient delivery.
Promotes the synthesis of specific proteins within cells, which play an important role in tissue repair and regeneration. Ultrasound also stimulates the movement of certain types of cells to the site of injury, having a knock on effect to accelerate healing.
Non-thermal effects of ultrasound also contribute to pain relief by altering nerve function and desensitizing nerve endings that perceive pain.