The use of needles in surgical practice goes beyond the general suturing of tissue and stitching. With the ever-increasing role of robotic surgery, it is essential not to underestimate the importance of haptic interaction in the training of needle insertion techniques.
Needle interaction with soft tissues is influenced by several factors including the geometrical characteristics of the needle, the speed of insertion, friction and the mechanical properties of the soft tissue. In this study, three types of textile fabrics generally used for medical device purposes were selected, the first of which was a nonwoven nanomaterial, the second a knitted material and the third a woven material.
While the shape of the needle insertion force and displacement curves differed between the selected materials and the type of inserted needle, a number of similarities were observed. With respect to the compact materials, i.e. human skin and the nonwoven material, the round-shaped tip needle generated higher insertion force peaks for all the tested samples while, conversely, the diamond-shaped tip needle produced higher insertion peak forces for the more structured, i.e. the knitted and woven materials.
The insertion force required for the skin samples was significantly higher than for the other tested (synthetic) materials.