Ultrasonic device part I: Overview

Abstract

Ultrasound is over 20 khz, which represents the upper frequency limit of human hearing. Acoustic vibrations are generated when piezoelectric materials on the thin disc-shaped transducers expand and contract. Although low frequency ultrasound devices have been used widely in the dermatologic area for a long time, the mechanism and side effects have been overlooked. A low-frequency ultrasound device has many benefits on the cosmetic dermatology area by thermal effect, vibration effect, and increase of transdermal delivery of lipophilic drugs or cosmetics. However, there have been reports of dermatitis, dyspnea, dizziness, and burns after treatment with ultrasound. Therefore, the use of this device should be under a doctor's supervision.