Yes, there are usually considerable differences. Physiotherapy ultrasound is usually of 1MHz (and sometimes 3MHz) frequency and of maximum power of around 10 Watts. Quite often it is used at a fraction of this maximum power, usually anything between 1 Watt and 5 Watts. This is because physiotherapy ultrasound is meant to stimulate and it is also used in a very small area, hence the low powers. Sometimes, low frequency ultrasound (300kHz) is used in physiotherapy but at very, very low powers (0.5-1 Watt). Some machines used in beauty, for cellulite reduction or other purposes, can also be of…