Acoustic and thermal outputs of commercially available therapeutic ultrasound devices

Therapeutic ultrasound, which uses mechanical waves to apply therapy to tissue, is a growing field with applications for physical therapy and improved recovery. This study investigates the acoustic and thermal output characteristics of four therapeutic ultrasound systems, with an aim toward appreciating performance similarities and differences, which is essential to rational experimental design, both on the bench and in the clinic. Acoustic output varied from 0.17 W to 1.14 W, and temperature change mediated in ex vivo muscle tissue ranged from 0.5°C to 3.4°C at a depth of 2 cm. These notable differences reinforce the importance of not considering all therapeutic ultrasound devices equal.