needle electrode
A fine wire through which electrical current may flow when attached to a power source; used to carry high frequency electrical currents that create heat or destroy diseased tissue (called radiofrequency ablation) or seal blood vessels. There are two types of needle electrodes: a simple straight needle; and a straight, hollow needle that contains several retractable electrodes that extend when needed. Needle electrodes may also be a part of devices that monitor electrical activity for diagnostic purposes such as in the performance of electromyography and nerve conduction studies.