The waves are generated by a piezoelectric effect caused by vibration of crystals within head of wand/probe. The sound waves that pass through skin cause a vibration of local tissues. This vibration or cavitation can cause a deep heating locally though usually no sensation of heat will be felt by patient. In situations where a heating effect is not desirable, such as a fresh injury with acute inflammation, ultrasound can be pulsed rather than continuously transmitted.

Ultrasound can produce many effects other than just potential heating effect. It has been shown to cause increases in tissue relaxation, local blood flow, and scar tissue breakdown. The effect of increase in local blood flow can be used to help reduce local swelling and chronic inflammation, and, according to some studies, promote bone fracture healing. The intensity or power density of ultrasound can be adjusted depending on desired effect. A greater power density (measured in watt/cm2 is often used in cases where scar tissue breakdown is goal.

I am always a careful driver, so my attention was focused on my driving, but my thoughts were elsewhere. Suddenly, I noticed sign warning that highway was coming to an end just ahead. Only then did I realize that I had missed my exit!

Has that sort of thing ever happened to you?

This situation is an excellent illustration of why I consider message of "Mindful Awareness" to be so very important. Consider that all of us are traveling down highway of life. Each of us has an idea of which route we would like to be taking, but we must be constantly mindful or else we risk missing our turning points.

Sometimes a missed turn can be fixed by taking another turn and circling back. Sometimes an even better route presents itself. But sooner or later everyone will find themselves at end of highway and many people will be unprepared for sudden ending of journey. "I was so sure that highway was longer than this!" they'll say.