Design and application of low-frequency ultrasound and its combination with laser radiation in surgery and therapy.

Further development of combined laser-ultrasonic medical technologies is presented. An analysis is made of the main effects produced by low-frequency ultrasound on biological tissues. These effects include cavitation, acoustic streamings, acoustic pressure, and mechanical influence. Possible application of low-frequency ultrasound is considered in regard to tumor therapy, bactericidal treatment of infectious tissues, and spray treatment of head and neck wounds. Some limitations of ultrasound application in medicine are discussed, and the feasibility of combining laser radiation with ultrasound is studied. A number of new laser-ultrasonic combinations are put forward and developed. They embrace the combination of photodynamic therapy with ultrasonic tumor therapy (sonophotodynamic therapy), laser-ultrasonic wound treatment (spray treatment), and laser-ultrasonic drug delivery (photophonophoresis). Some of the above-mentioned technologies were tested experimentally, and the results obtained are considered.