(a) Insulated needle electrodes
(b) Coaxial needle electrodes
( c)Bipolar coaxial eletrodes:
(d)Fine- wire electrode:
- There are percutaneous electrode where lead wire crosses skin.
- They are internal electrodes in which connections are implanted on electronic circuitry.
- No electrolytic gel is required because extra-cellular fluid is present.
- The basic needle consists of solid needle, made up of stainless steel with sharp points.
- The shank of needle is insulated by varnish, only tip is left exposed.
- The shank is insulated by insulating varnish.
- The lead wire is attached to other end & joint is encapsulated in plastic hub to protect it.