| abstract |
An electrosurgical instrument has a conductive elongated member, a connector for connecting an external electrical power supply to the proximal end of the elongated member, an electrosurgical implement at the distal end of the elongated member, and an insulative parylene coating covering the elongated member. The thickness of the parylene coating is in the range of approximately 1 to 6 mil inches, and preferably 2 to 3.5 mil inches. In the preferred embodiment, the surfaces of the instrument that are to remain uncoated are first masked. The unmasked surfaces are roughened and then dipped in a liquid silicone. The parylene coating is then applied by vacuum vapor phase deposition and annealed. A parylene coating can also be applied to portions of the electrosurgical implement for insulation. A thin parylene coating can be applied to the blade of the instrument as a non-stick coating for easier cleaning. If the instrument is an endoscopic electrosurgical instrument used with a trocar sleeve having a valve to receive the shaft, wear between the valve and the shaft can be reduced by applying a parylene coating to the interior surface of the valve. |