An ultrasound machine makes images so that organs inside the body can be examined. The machine sends out high-frequency sound waves, which reflect off body structures. A computer receives the waves and uses them to create a picture.

Diathermy is a treatment that provides deep heat to your tissues. It helps relax muscles and joints, reduce swelling and improve blood flow. Diathermy uses radio and sound waves to warm up the tissues beneath your skin

In the developed world, the most frequent type in use is the continuous-flow anaesthetic machine or “Boyle’s machine”, which is designed to provide an accurate supply of medical gases mixed with an accurate concentration of anaesthetic vapour, and to deliver this continuously to the patient at a safe pressure and flow.