Failure behavior and influence of surgical tool edges in soft tissue cutting

Failure on the cutting edge of surgical tools can affect their repeated use and is an important issue that needs to be addressed. The influence of the cutting length and soft tissue type on cutting forces, surface morphology, surface roughness, corner radius and sharpness index of the cutting edges on surgical blades in the process of soft tissue cutting was investigated in this study and the failure behavior of the soft tissue cutting edge was discussed. The friction force and the corner radius remain relatively stable with increased cutting length, while sharpness index, surface roughness, cutting force and stiffness force increase. Biological materials have a significant impact on the sharpness index of the cutting edge (p = 0.000 < 0.05). A cutting durability decay model based on sharpness index and a failure model, where the main failure form is tissue adhesion wear in soft tissue cutting, are proposed in this paper. The timely removal of the surface adhesion on surgical tools can effectively decrease rapid failure. A precise regression model of the relationship between cutting force and corner radius was derived under the condition of a stable cutting state (R2 = 0.95), which connected the macro cutting force with the micro cutting edge structure. Anti-adhesion technology or sharper cutting edges are recommended to be adopted in surgical tool manufacturing to reduce the probability of adhesion failure to surgical tools.