Effect of handle design and target location on insertion and aim with a laparoscopic surgical tool.

Two laparoscopic tools, a scissor-type grasper and an ergonomically designed grasper, were compared in terms of operation efficiency and physical workload while inserting into a simulated abdomen and aiming five cross-shaped targets. Thirty right-handed novice participants performed the tasks with five tool-grasping hand postures at two computer monitor angles that simulated reaching an organ during laparoscopic surgery. When comparing the two free style hand postures used, there was a significant improvement in operation efficiency. This demonstrated that the participants quickly became familiar with the Intuitool by finding new hand postures that will significantly help them reach the target faster and more accurately. The 45( composite function) monitor angle showed the worst accuracy and deviation, the 0( composite function) monitor angle showed the best accuracy and smallest deviation with the upper target. Thus it is recommended that the camera trocar be placed directly above the organ of interest, and the part of the organ to be reached should be displayed slightly above the center of the feedback monitor. For physical workload, the method of gripping the tools was the most important factor. The scissors-type tool caused the largest wrist flexion, in contrast both free styles hand postures with the Intuitool showed the least wrist flexion.