Medical Equipment Glossary

High-energy X-rays are used to treat cancer, since some cancer cells are more susceptible to damage from electromagnetic radiation than ordinary cells. The energy of the X-rays (usually expressed in kilovoltage) determines the depth of penetration. Thus for superficial X-rays (suitable for skin treatment) 50-150 kV may be used.

A paper chart recorder for producing graphs of one variable against another. It has a separate signal amplifier to drive the pen in the X (horizontal) direction and the Y (vertical) direction. Such recorders are used in the audiology department for plotting acoustic impedance change against outer ear pressure, and for other applications to plot one variable against another.