I want to find mid point of biggest and relatively straighter vein in the live tracking video frame for insertion of needle and point a red laser light to that point mounted on a pan tilt of servos. How can I get that best suitable point of insertion

NIR infrared have been used to enhance venous contrast. Adaptive threshold and some morphological operations have been applied to get a point on vein for needle insertion as shown in image attached. But there is some false detection. How that can be removed?