A novel computational fracture toughness model for soft tissue in needle insertion

Area of Science:

• Computational mechanics
• Biomedical engineering
• Surgical simulation

Background:

• Accurate needle-tissue interaction models are crucial for percutaneous puncture vascular intervention in endoscopic liver surgery.
• Existing models often overlook key parameters like Young's modulus and organ capsule structure, limiting fracture toughness estimation.
• Tissue fracture toughness is vital for understanding crack propagation, tissue deformation, and target displacement during procedures.

Purpose of the Study:

• To develop a novel computational fracture toughness model for needle-tissue interaction in liver surgery.
• To incorporate insertion velocity, needle diameter, and Young's modulus into the fracture toughness estimation.
• To validate the model's accuracy against experimental data and analyze influencing factors.

Main Methods:

• Proposed a computational fracture toughness model integrating insertion velocity, needle diameter, and Young's modulus.
• Utilized energy modeling with integrated shell and 3D solid elements to estimate tissue surface deformation.
• Constructed a testbed to experimentally evaluate the model's predictions under varying conditions.

Main Results:

• The computational model's estimated fracture toughness showed strong agreement with physical experimental data.
• Sensitivity analysis identified key factors influencing fracture toughness during needle insertion.
• Model robustness was confirmed through analysis with varying observation noise in Young's modulus and displacement.

Conclusions:

• The developed computational model accurately predicts tissue fracture toughness, enhancing needle-tissue interaction models.
• Considering Young's modulus and insertion parameters improves the precision of fracture toughness estimation in surgical interventions.
• The model provides a robust framework for simulating needle-tissue mechanics in endoscopic liver surgery.