| Aiming at the problem that the puncture friction force of the cannula electrode during the puncture process in deep brain stimulation surgery damages the brain tissue on the puncture path,this paper combines the antifriction effect of the microtexture and proposes the idea of preparing the microtexture electrode.Design and screen the morphology and spacing of micro-textured electrodes,build a micro-textured electrode processing platform,perform micro-textured electrode puncture experiments on pig brains,observe the surface brain tissue adhesion and the value of the frictional force growth rate,and determine the most anti-friction effect Excellent micro-textured electrode.In deep brain stimulation surgery,the outer wall of the cannula electrode is a φ1.5mm316 L stainless steel hollow cylinder,and the micro-texture type selects the pit type and the groove type.In this paper,round and square micro-pit textures and linear and linear interlaced micro-groove textures are processed on the surface of a φ1.5mm 316 L medical bone puncture needle with a spacing of 0.1mm～0.4mm.Laser processing is selected as the microtexture processing method,and the laser process parameters are optimized by orthogonal experiments.The optimization results are power 1.6W,repetition frequency85 k Hz,scanning speed 350mm/s,and scanning times 3 times.Combining the relationship between solid surface wettability and friction performance and the improvement of water droplet wettability in different micro-textured arrays,the micro-texture morphology and spacing that can effectively reduce friction are screened.Four kinds of micro-textured arrays with a pitch of 0.1mm～0.4mm were processed on the surface of a 316 L stainless steel plate.The contact angle was measured by a contact angle measuring instrument and compared with the contact angle of a smooth surface.The results show that the four types of microtexture arrays can improve the wettability of the 316 L stainless steel plate surface.The order of wettability is linear staggered,square,round,and linear;when the microtexture spacing is 0.1mm,the contact angle of water droplets is the lowest and the wetting performance is the strongest.Therefore,the distance between the micro-textured electrodes is set to 0.1 mm.The diameter of the sleeve electrode is small,the long diameter is relatively large,and it is a thin-walled hollow electrode with low rigidity,which causes the sleeve electrode to be easily deformed during clamping,and its straightness,rotation and runout accuracy are difficult to maintain;laser beam tool setting It is difficult to adjust the collinearity with the busbar of the casing electrode;the processing of micro-textured electrodes cannot be flexibly observed on-line and multi-angle in real-time during laser processing.Therefore,in order to improve the processing quality and processing efficiency of micro-textured electrodes,a micro-textured processing platform for deep brain stimulation cannula electrodes is designed to process micro-textured electrodes.A puncture platform was built to perform brain tissue puncture experiments with puncture speeds of 2 mm/s,3 mm/s,4 mm/s,and 5 mm/s.The NANO17 miniature sixdimensional force sensor was used to collect the puncture force during the puncture process and plot the puncture Force curve.Observation and analysis of the brain tissue adhesion on the surface of the micro-textured electrode and its frictional force growth rate.The results show that there is no brain tissue adhesion on the surface of the circular,square and linear interlaced micro-textured electrodes,and there is slight brain tissue adhesion on the surface of the linear micro-textured electrodes,and the friction force of the needle shaft of the linear interlaced micro-textured electrodes increases.The rate value is the lowest,and the growth rate is slower.Therefore,the micro-textured electrode with the best anti-friction effect is a linear interlaced micro-textured electrode with a pitch of 0.1mm. |
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