US Patent 7135020 Electrosurgical instrument reducing flashover

An electrode assembly for use in combination with an electrosurgical instrument which includes opposing end effectors and a handle for effecting movement of the end effectors relative to one another. The assembly includes a housing having one portion which is removably engageable with the electrosurgical instrument and a pair of electrodes each having an electrically conductive sealing surface and an insulating substrate. The electrodes are removably engageable with the end effectors of the electrosurgical instrument such that the electrodes reside in opposing relation relative to one another. The insulating substrate is made from a plastic material having a high Comparative Tracking Index to reduce the incidence of flashover.