Evaluation of liver tissue damage and grasp stability using finite element analysis

Area of Science:

• Biomedical Engineering
• Surgical Device Design
• Computational Mechanics

Background:

• Minimizing tissue damage and ensuring grasp stability are critical in surgical grasper design for minimally invasive surgery.
• Existing research predominantly relies on in vitro experiments and visual inspection for assessing tissue injury and grasp security, with limited quantitative analysis.

Purpose of the Study:

• To develop a robust methodology for quantifying tissue damage and grasp quality in diverse grasper-tissue interactions.
• To provide a computational framework for evaluating surgical grasper designs and improving surgical simulators.

Main Methods:

• Utilized finite element analysis (FEA) to simulate the interaction of eight different graspers (varying radii of curvature and tooth sizes) with liver tissue.
• Incorporated nonlinear material properties for tissue and derived damage evaluation from in vivo experimental data.
• Analyzed stress, tissue damage, and grasp stability through contact status examination.

Main Results:

• Increasing the radius of curvature of graspers led to a reduction in computed tissue damage.
• A smooth wave pattern on graspers decreased tissue damage but increased the area of tissue slippage.
• FEA provided quantitative metrics for peak stress, integrated stress, and tissue damage.

Conclusions:

• The developed FEA methodology offers a valuable tool for researchers to design and test novel surgical graspers.
• This approach can enhance surgical simulator fidelity by incorporating realistic tissue properties and predicting tissue damage outcomes.