A Combination Method of Artificial Potential Field and Improved Conjugate Gradient for Trajectory Planning for Needle Insertion into Soft Tissue

10.5405/jmbe.1804

Pan Li；Shan Jiang；Jun Yang；Zhiyong Yang

Needle insertion ； Trajectory planning ； Artificial potential field ； Local minimum ； Improved conjugate gradient

Journal of Medical and Biological Engineering

34卷6期（2014 / 12 / 01）

568 - 573

英文

To reduce postoperative complications and unwanted side-effects, injury to vital tissues and/or nerves should be avoided in minimally invasive surgery. In this paper, a combined trajectory planning algorithm that uses an artificial potential field (APF) method in conjunction with an improved conjugate gradient algorithm (ICGA) is proposed. Fascial tissues create local minima (LM) when the APF method is applied, which may lead to needle oscillation. The proposed method finds sub-goal points using ICGA to escape from LM. Thus, a complete smooth trajectory passing through anatomical obstacles is obtained. Needle guidance and steering can be performed through a unicycle model. The optimal APF function is obtained by adjusting parameter n. When n=6, the distance between LM and the target reached its minimum (1.0198), which shows that Point 6 is closest to the target and n=6 performs higher search efficiency. The experimental simulation shows combination method has higher efficiency (13.45% higher) compared to APF method, which requires just a few tenths of a second on a standard PC.