It is produced by a piezoelectric crystal, which converts electricity into acoustics energy, through the mechanical deformation of the piezoelectric effect.
In physiotherapy, ultrasound is commonly used in combination with other forms of treatment including hot patches, cold patches, electrotherapy.
An important application of the ultrasound is phonophoresis.
Phonophoresis is a technique by which molecules of chemical preparations e.g. anti-inflammatory mainly and analgesics are driven deeper into phlegmatic tissues with the help of sound field forces.