Methods of control for minimizing extra-fine needle deflection with a combination of vibration and rotation in the lower abdomen

Abstract

Cancer vaccine therapy is a novel treatment method which uses an extra-fine (0.53 mm in diameter (25 G)) needle to deliver a tumor-specific vaccine directly into a tumor. This method is expected to deliver an effective treatment with few side effects. However, the procedure is very difficult to perform because of needle deflection. We intend to develop a needle insertion robot to combat this deflection and deliver the vaccine successfully. The key features of the robot were developed to minimize needle tip deflection while traversing complex tissues which is composed of various tissues. In this paper, as targeted to lower abdomen, we propose a control method for minimizing needle tip deflection during insertion through vibration and axial rotation. The effectiveness of the proposed method was evaluated in artificial and biomaterial tissues found in the lower abdomen (muscle, bowel, and skin). Results demonstrated that the effectiveness of vibration and rotation was changed depending on the kind of the tissues. The rotation was effective to the thick tissues (muscle and skin) and the vibration was effective to membranous tissues (bowel). Based on the results, our method used vibration and rotation when the needle is inserted into the skin and muscle and only vibration when traversing through soft tissue such as the bowel. In conclusion, the proposed method can minimize needle tip deflection robustly in a lower abdomen phantom.

Preoperative Needle Insertion Path Planning for Minimizing Deflection in Multilayered Tissues

“…We verified this by comparing the calculated scores and needle tip deflections measured in these experiments. The target size ( r tar ) is set to ±2 mm in this experiment [12]. Six trials are performed for each entry position for all experimental scenarios.…”

“…In addition, since PVC phantom and chicken meat, used in this paper, are almost homogeneous, we will verify the proposed path planning with more realistic models including a lot of fibers such as a hog meat. Focusing on a lower abdominal insertion as in our recent work, needles have to pass several intestinal lumens, which are hollow organs and cause a different type of deflection compared to layered tissues [12]. With those realistic tissues, we consider that the deflection probability will be more effective because the variance of deflection may be increased due to the tissue characteristics.…”

“…Previously, we proposed an approach that facilitates the straight insertion of the fine needle by minimizing needle tip deflection [12–13]. As an insertion method for minimizing needle tip deflection and targeting errors, needle insertion with axial rotation is a common approach [14–16].…”