Ex vivo experimental needle insertion force model for minimally invasive surgery

The fracture strength of the soft biological tissue aimed by the surgical needles acts as a serious character in clinical processes, for example, robotic-controlled needle steering, catheter insert, suturing, biopsy, etc. Despite the several investigational mechanisms on the fracture toughness of hard tissues, for example, dental tissue, bone, etc., only a very restricted number of investigations have concentrated on soft biological tissues, wherever the effects do not display any constancy mostly because of the casualness of the inserting/puncturing needle geometry. Tissue deformation during needle insertion is one potential source of inaccuracy. In modern medical science, the application of minimally invasive (MI) interventional tools for soft tissue surgery potentially reduced trauma, less blood loss, and less recovery times for the patient. One of the biggest challenges is tissue deformation affected by needle penetrating force, leading the undesired target engagements. The flexibility of soft tissue can create inaccurate needle insertions. With the purpose of the report on this matter, we experimented on the surgical needle insertion investigations on ex vivo duck livers with different diameters of the needle. A distinctive value for fracture toughness was attained for the ex vivo duck liver tissue by appropriately a link to the stiffness values assessed from the set of insertion experimentations. To confirm the investigational outcomes, a finite element model (FEM) of the ex vivo liver was established, and its hyper-viscoelastic properties were projected through an energy-based fracture mechanics method. The perforation forces assessed from the FEM simulations display an outstanding agreement with those developed from the physical investigations for all surgical needle geometries.