Study Of Material Property And Application Of Microdissection Tungsten Needle Electrode

Minimally invasive surgery is a technology which refers to the minimal trauma caused during surgery and only a slight wound leaving after surgery with the use of minimally invasive surgical instruments. It has been hailed as one of developing directions of surgical in the 21 st century. Microdissection tungsten needle is a minimally invasive surgical instrument for high-frequency electric knife. It has a ultra-sharp needle tip of which radius is less than 15 microns. In clinic, It is quick in cutting, cuts precisely and has small tissue thermal damage. And it’s operated flexibly.In this paper, the influence and mechanism of rare earth dopants to discharge performance have been studied under the conditions of 2A and 50 A current. It indicates that the thermionic emission poperties of the rare earth tungsten electrodes are improved compared with pure tungsten electrode. WT20 and WC20 electrodes are adapted to operate only in the condition of lower current. WL20 electrode can work in a relatively stable condition. WY20 electrode has an absolute advantage when working under the condition of high current for a long time. However, the ability of thermionic emission of the tungsten electrodes is similar when used for high-frequency electric knife under the condition of small power.It has been researched that the mechanical property of WP, WT20 and WC20 between 200 ℃ and 1000 ℃.The result shows that the plasticity of the tungsten electrode materials is increased with the rise of temperature. At the same temperature, the plastic of WP is best.The bending formability of tungsten electrodes was studied with self-developed bending equipment. It’s found that the relative bending radius has a linear relation with bending angle. The minimum relative bending radius of the tungsten electrode materials decreased with the rise of temperature between 25℃ and 250℃. The bending springback angle is controlled between 8°and 10°. Finally, the reasonable parameters of bending process of the tungsten electrode materials has been obtained.The polishing voltage of tungsten is between 0.98 V and 2.8V when the concertration of Na OH solution is 1mol/L. The electro-corrosion cracking susceptibility of tungsten electrode with initial microcracks on surface increases with the increase of the concertration of Na OH solution and the polishing voltage.It’s safe for microdissection tungsten needle to be used in minimally invasive surgery by researching animal experiment and clinical application. And it can be completely suitable in precise surgery.