Friction dynamics of trocars

Abstract

For some trocars, friction can be as great as the forces associated with instrument-tissue interaction. At movement reversals, friction fluctuates due to deformations of the rubber and silicon parts of the sealing mechanism. Such high variance can deteriorate surgical performance during high precision tasks (e.g., tissue manipulation) that typically involve many changes in movement direction. Comparisons of the investigated trocars indicate that the friction magnitude and variance can be reduced easily by changing the properties of the sealing cap or by lubricating the instruments.

Force feedback and basic laparoscopic skills

“…He found that friction between instrument and trocar differed greatly among various designs of trocars. According to this study, the friction in the trocar varies between 0.25 and 3.0 N [20].…”

“…Some of these causes have already been investigated [19,20]. Sjoerdsma et al [19] focused on the mechanical transmission characteristics of four types of graspers.…”

“…Van den Dobbelsteen et al [20] measured friction characteristics of six commonly used trocars in laparoscopy. He found that friction between instrument and trocar differed greatly among various designs of trocars.…”

Effect of laparoscopic grasper force transmission ratio on grasp control

“…The laparoscopic graspers were placed through a trocar (type Xcel 5; Ethicon ENDO-Surgery Inc., Cincinnati, OH, USA) with low friction to minimize the disturbance of forces caused by other elements [15]. Figure 1 shows the experimental setup for the condition of a laparoscopic grasper.…”

“…The transmission of forces from the tip of the instrument to the handle is limited and significantly disturbed, depending on the type of grasper and the kind of manipulation action (e.g. trocar friction, abdominal wall resistance, scaling factors, mechanical construction, and efficiency) [1,[11][12][13][14][15].…”